A study was conducted to investigate the effects of object weight on the regulation of grip force during holding tasks using a precision grip. In addition, variations in grip force among individuals were examined. Using a force transducer-equipped grip apparatus, grip force, load force and the vertical position of the object were measured continuously while using load weights of 0.98N, 1.96N, and 2.94N under sandpaper grip surface conditions. From the recorded data, peak grip force, average static grip force, slip force, safety margin force (average static grip force-slip force), and time to stabilize the grip force from the peak grip force were evaluated.
It was found that both the slip force and safety margin force increased with object weight. The static friction coefficient, estimated from the slip force and load force, deviated from Amonton's law at a lower load force. The deviation was believed to be due to the influence of the viscoelastic nature of finger skin. An increase in safety margin force with object weight was considered to be related to the psychological reaction to the increased heaviness of the object. Indeed, in trials that included unexpected changes in object weight, the safety margin force was increased, which also seemed to be associated with the psychological reaction to uncertainty about the object's weight. A relatively large inter-subject variation was revealed for both the slip force and safety margin force.

A 59-year-old man with myocardial infarction underwent 4-vessel coronary artery bypass grafting. After operation, on the 9th hospital day, fever, dehiscence of the median wound, and pus discharge were observed. Methicillin-resistant Staphylococcus aureus (MRSA) was detected in the wound, and median wound curettage and removal of the sternal bone wire were performed. The infection also involved the substernal area and anterior mediastinum, and a diagnosis of mediastinitis was made. After wound cleansing and antibiotic (vancomycin) administration, inflammatory reactions decreased, and MRSA disappeared from the wound. The wound spontaneously closed, and complete closure required 60 days. On the 75th hospital day, pain from the right shoulder to the neck and numbness in the upper limbs suddenly developed. MRI revealed vertebral body destruction at C5-6, and a diagnosis of cervical osteomyelitis was made. The spinal cord was compressed, and there was a risk of spinal cord injury below the cervical spine. After consultation with orthopedic surgeons, cervical anteroposterior fixation was performed, he improved, and was discharged. We report a patient with MRSA mediastinitis complicated by cervical osteomyelitis who required emergency surgery.

The electromyographic (EMG) activities of the back and thigh muscles while pedaling a bicycle ergometer at different load levels (300, 450, 600 and 750 kpm/min) and during walking and running at top speed up and down a staircase were investigated in children classified as physically less and more active than average. Each child underwent a battery of physical fitness tests to determine his physical fitness level relative to the national standard. Although the physiques of the inactive and active children did not differ, there were considerable differences between their back-lift, grip and knee-extension strengths, and the maximum anaerobic power, and 50-m dash performances of the two groups. The EMG data for each of the different tasks over selected periods (bicycle pedaling: 5 complete revolutions, staircase task: 5 stepping cycles) under different workload conditions were full-wave rectified and integrated (IEMG) . Under low workload conditions (ergometer tasks at 300 and 450 kpm/min and walking up and down stairs), the mean IEMG values (mIEMG) of all the muscles tested did not differ significantly in the inactive and active children. However, for all the higher workload tasks (pedaling at 600 kpm/min and running up and down stairs), the mIEMG values of the erector spinae muscles in the inactive children were significantly lower than those of the active children, and the difference increased gradually as the workload increased. This trend was even more marked when normalized mIEMG values were used. When the children ran up and down stairs at top speed, the inactive group had lower thigh, gluteus maximus and erector spinae muscle mIEMG values than the active group, and the difference between the normalized mIEMGs of the erector spinae muscles of the two groups showed a particularly strong statistical significance (P<0.01) when running both up and down stairs. As a similar trend was observed when the workload was maintained at a high level for the bicycle pedaling task, we concluded that at least part of the difference between the muscular activities of the two groups of children demonstrated when they carried out the running task was attributable to differences in the development of the muscle fibers and neuronal mechanisms of the erector spinae muscles.

The effects of the surface friction of a grasped object on the regulation of grip force during holding tasks using a precision grip were investigated. Using a force transducer-equipped grip apparatus, the grip force and load force acting on the object were measured continuously while surface materials (silk, wood, suede and sandpaper) and load weights (0.98N, 1.96N, 2.94N, 4.90N and 9.81N) were varied. From the recorded data, the average static grip force, slip force, safety margin force and static friction coefficient were evaluated.
It was found that both the slip force and safety margin force increased as the slipperiness of the object surface increased. Significant interactions between surface type and weight were observed in the slip force and static friction coefficient. The interaction effect resulted from the fact that the frictional relationships with the fingers changed according to both weight and surface conditions. This was considered due to the viscoelastic nature of finger skin. An increase in the safety margin force with surface slipperiness was considered due to psychological reaction, probably fear of dropping the object. Unexpected changes in surface conditions caused a greater safety margin force than trials without a surface change, which might also have been associated with psychological reaction to uncertainty of the new surface condition. A relatively large inter-subject variation was found in the slip force and safety margin force relative to slippery surfaces.

We evaluated the surgical strategy for thoracic aortic aneurysm associated with abdominal aortic aneurysm. From January 1982 to March 1999, 24 consecutive patients underwent surgical treatment for thoracic aortic aneurysm with abdominal aortic aneurysm. Staged operation was performed if one was only slightly dilated, but extensive operation was needed if the size of both aneurysms was greater than 6cm. In cases of thoracic aortic aneurysm with abdominal aortic aneurysm up to 4cm in size, surgical treatment was performed only for the thoracic aortic aneurysm. Circulatory support during operation was established from the ascending aorta, and circulatory arrest with deep hypothermia and retrograde cerebral perfusion were used for brain protection during surgery for thoracic aortic arch aneurysm. Hospital mortality was 12.5% (3/24 cases). The causes of death were cerebral infarction and respiratory failure. Antegrade systemic perfusion and aortic no-touch technique were an effective method of surgery for thoracic aortic aneurysm with abdominal aortic aneurysm to avoid perioperative embolism and major complications. We successfully performed staged operation, but regular radiographic follow-up was needed.

(Objective) Neoadjuvant hormonal therapy (NHT) before radical prostatectomy promotes the downstaging of primary lesions. A retrospective analysis was conducted of the relationship between NHT durations and positive surgical margin rates, as well as between positive surgical margin rates and three types of prostatectomy (antegrade radical prostatectomy, retrograde radical prostatectomy, and laparoscopic radical prostatectomy (LRP)).;(Materials and Methods) This study was a retrospective analysis of 257 patients treated with radical prostatectomy during the three years between April 2002 and March 2005. Of the 257 patients, 190 were treated by NHT. NHT durations were classified into “not conducted,” “<1 month,” “1-3 month,” “3-6 month” and “>6 month,” and the relationship between positive surgical margin rates and NHT durations was investigated. Seventy-four patients underwent antegrade radical prostatectomy, 131 were treated with retrograde radical prostatectomy, and 52 underwent LRP. Positive surgical margin rates were investigated according to the types of prostatectomy, as well as according to prostate-specific antigen (PSA) levels upon diagnosis.;(Results) Positive surgical margin rates were 53.8% in the “not conducted” and “<1 month” groups, 38.8% in the “1-3 month” group, 32.4% in the “3-6 month” group, and 10.7% in the >6 month” group. Positive surgical margin rates after open surgery (antegrade and retrograde) tended to decrease when NHT durations were longer, while those after LRP tended to increase inversely. No correlation was observed between PSA levels upon diagnosis and positive surgical margin rates or between presurgical PSA levels and NHT durations.;(Conclusion) Positive surgical margin rates were not significantly different when patients were treated with NHT for 1-3 months, but they tended to decrease when NHT was for >6 months. However, positive surgical margin rates after LRP increased when NHT continued for longer periods of time. This may the result of fibrous adhesion in the vicinity of the prostate due to long-term NHT which made the surgical margins unclear.
Prostatectomy ; month ; Positive ; LDL-Receptor Related Protein 1 ; public service announcement

In Japan, doctors inexperienced stent-graft new devices are required to secure agreement on criteria and choice of the device size in endovascular aneurysm repair (EVAR) from experienced doctors. It was hoped that strict patient selection might reduce the learning curve for initial successes in given procedures. In a leading center in Japan, a number of cases which were scheduled for operation at other institutes were evaluated anatomically. We surveyed the initial success of Zenith AAA system implantation in the remaining cases by inexperienced doctors and evaluated the results. This study aimed to verify the validity of strict patient selection in improving the success rate of inexperienced doctors. We enrolled 112 consecutive patients from 19 institutes, who were scheduled for repair between January and October in 2007. All patients were evaluated on the basis of a less-than-3mm reconstructed CT image. Mean patient age was 76±5.7 years. All cases satisfied the Zenith's anatomic prerequisites. Fifteen cases were excluded for various reasons, the major reason being insufficiency of the proximal landing zone (LZ) length, angle and contour. The second reason was difficulty to approach via the iliac artery. Ninety seven cases were included, of which 17 cases were low-risk candidates for EVAR. Medium-risk seventy two cases requiring some advice to avoid problems with device size, technique of implantation and choice of main-body side. Eight cases were high-risk, requiring the presence of an experienced surgeon. Excluded cases had significantly shorter proximal LZ, larger aortic diameters 15mm below the renal artery and tortuous access routes on preliminary measurement by inexperienced doctor. Perioperative mortality was 0%, while the major complications were injury to the iliac artery in one high-risk case and thromboembolism of the superficial femoral artery in another. Perioperative proximal type I endoleak occurred in 5 cases. In 3 of these cases, the endoleak was eliminated by implantation of a Palmatz stent. In the other 2 cases, it disappeared within a month without additional procedures. These cases had a significantly greater angle between the proximal LZ and the suprarenal aorta and significant amount of mural thromboses in the proximal LZ. Perioperative type III endoleak occurred in 3 cases. In all cases the endoleak was eliminated by additional procedure. Perioperative type II endoleak occurred 8 cases. In 3 of these cases, the endoleak disappeared within a month. In the 5 other cases, the endoleak did not disappear. Mid-term results showed iliac leg thromboembolism in one case and new type II endoleaks in 3 cases. Type II endoleak occurred in cases which had significantly greater angles between the proximal LZ and the aneurysm. The results which were evaluated in our center had excellent perioperative and mid-term outcomes. We think this evaluation system is effective for risk assessment and reduces the learning curve in EVAR. In anatomically marginal cases, it is possible for proximal type I endoleak and injury of the iliac artery to occur. It is impossible to exclude these marginal cases if treatment need for EVAR is a priority. In these cases, lessexperienced operators should be trained in troubleshooting techniques in advance.

In the last decade, 78 patients received operations for abdominal aortic aneurysms with a transperitoneal approach (TP) while in 82 patients we used an extraperitoneal approach (EP). Forty-two patients in the TP group and 40 in the EP group who required no concurrent repair of the inferior mesenteric artery, renal artery or lower extremity arteries were compared. There was no difference between the two groups in mean operative time, mean amount of intraoperative bleeding or mean amount of required homologous blood transfusion. The mean interval after surgery to beginning peroral alimentation and the mean duration of postoperative fluid therapy were significantly shorter in the EP group than in the TP group. An extraperitoneal approach for abdominal aortic reconstruction is preferable for an early postoperative recovery.

The effects of aging on adaptive force control of precision grip while manipulating a small object were compared between older (84.2±8.9 yrs, n=33) and young adults (19.1±0.24 yrs, n=18) from the following perspectives: (1) adaptation to an unfamiliar object with uncertain physical properties during 16 consecutive lifts ; (2) adaptation to an object with a non-slippery (sandpaper) surface during 12 consecutive lifts, followed by 12 consecutive lifts with a slippery (silk) surface ; and (3) adaptation to objects with different weights (0.49, 0.98, 1.96 and 2.94 N) during 24 lifts (6 consecutive lifts for each weight) .During each trial, grip and load forces were monitored. Safety margin force and slip force were evaluated from the data obtained.
The majority of older adults employed a considerably greater safety margin for an unfamiliar object in the initial trials than did young adults, while the minority of the older adults were able to adapt their safety margin force with a few trials, like the young adults. The older adults who overestimated the safety margin force, however, successfully adjusted their grip force to more optimal levels with repeated lifts, suggesting that the adaptive capability of grip force remained even at 90 years of age. The adaptation of older adults, however, was found to be slower (i. e., required more trials) than that of young adults. Upon encountering surface friction change, the safety margin forces in older adults were more strongly affected by the previous surface condition than those in the young adults. In addition, adaptation to a non-slippery surface seemed more difficult than that to a slippery surface with aging. Upon encountering weight change, older adults showed more difficulties in scaling their safety margin forces according to object weights.
Slower adaptation and difficulty in adaptation to the friction or weight change in older adults may reflect the agerelated decline of tactile sensitivity which impaired the signaling of frictional conditions and various discrete events in the hand. In addition, the lift repetition for force adaptation may possibly reflect the age-related deficit or slowing of central processing capacities related to grip force production.