Biomedical subjects

Yoichi Shimada

Publications and source records attributed to Yoichi Shimada.

At least 37 records · Page 2Linked to original sources

PubMed2005

Contact area, contact pressure, and pressure patterns of the tendon-bone interface after rotator cuff repair.

BACKGROUND: The contact pressure and contact area at the tendon-bone interface after the most commonly used rotator cuff repair methods have not been investigated. HYPOTHESIS: There are no significant differences among the transosseous, the single-row suture anchor, and the double-row suture anchor techniques in terms of contact pressure, contact area, and pressure patterns at the tendon-bone interface. STUDY DESIGN: Controlled laboratory study. METHODS: After creating a full-thickness supraspinatus tendon tear in 10 cadaveric shoulder specimens, we inserted pressure-sensitive film between the tendon stump and the bone, and we repaired the tear by (1) transosseous, (2) single-row suture anchor, and (3) double-row suture anchor techniques. RESULTS: The contact area of the double-row technique was 42% greater than that of the transosseous technique (P < .0001) and 60% greater than that of the single-row technique. The contact area of the transosseous technique was 31% greater than that of the single-row technique (P = .0015). The average pressures of the single-row and double-row techniques were 18% (P = .014) and 16% (P = .03) greater, respectively, than that of the transosseous technique, but there was no significant difference between the single-row and double-row techniques (P = .915). CONCLUSIONS: The double-row technique produced the greatest contact area and the second-highest contact pressure, whereas the single-row technique created the highest contact pressure and the least contact area. The transosseous technique produced the second-greatest contact area and the least contact pressure. CLINICAL RELEVANCE: The double-row suture anchor technique and the transosseous technique may provide a better environment for tendon healing.

Absorbable Implants↗

PubMed2005

Factors related to spinal mobility in patients with postmenopausal osteoporosis.

Quality of life in patients with spinal osteoporosis is impaired by the decline of spinal mobility. However, the factors related to the spinal mobility in these patients are still unclear. We evaluated the possible factors affecting spinal mobility in patients with postmenopausal osteoporosis. A total of 128 postmenopausal women with osteoporosis aged over 50 years (mean, 70 years) were included in this study. The thoracic and lumbar kyphosis angles and range of motion (ROM) of the total spine were measured in the upright position and at maximum flexion/extension with a computer-assisted device. The paravertebral muscle thicknesses (PVMT) of thoracic and lumbar spine in the upright position were measured using an ultrasound unit. The number of vertebral fractures was evaluated with radiographs of the spine. Isometric back extensor strength (BES) was evaluated with a strain-gauge dynamometer. Correlations between these variables were then analyzed. Age (r=-0.412), lumbar kyphosis angle (r=-0.284), BES (r=0.369), PVMT at the lumbar spine (r=0.227) and the number of vertebral fractures (r=-0.260) showed significant correlations with total spinal ROM (P<0.05). However, no significant correlations were observed between the total spinal ROM and PVMT at the thoracic spine (r=-0.069) or thoracic kyphosis angle (r=-0.138). Multiple regression analysis revealed that the BES was the most significant contributor to the total spinal ROM. The present study suggests a possible association between BES and spinal mobility in patients with postmenopausal osteoporosis.

Aged↗

PubMed2005

Effects of reducing resistance, repetitions, and frequency of back-strengthening exercise in healthy young women: a pilot study.

OBJECTIVE: To determine the effects of reducing intensity or frequency of back-strengthening exercise on back extensor strength. DESIGN: Randomized controlled trial. SETTING: Exercises were performed in participants' homes. Instruction and measurements were performed at the rehabilitation center in the hospital. PARTICIPANTS: Fifty-eight healthy female volunteers (mean age, 20 y). INTERVENTIONS: Participants were assigned to 1 of 5 exercise intervention groups: control; standard protocol (STD) that has been shown to increase back extensor strength; weight reduction (WRD); repetition reduction (RRD); and frequency reduction (FRD). Back exercises involved lifting a weighted backpack while in a prone position. The study period was 12 weeks. MAIN OUTCOME MEASURE: Isometric back extensor strength. RESULTS: Back extensor strength increased significantly in all groups except the control group. The maximum increase was achieved by the STD group (39%), followed by the FRD (25%), WRD (22%), RRD (20%), and control (5%) groups. Percentage change in back extensor strength was significantly greater in the STD group than in all other groups except the FRD group. CONCLUSIONS: Back extensor strength in the WRD, RRD, and FRD groups was significantly higher at 12 weeks compared with baseline. Reductions in intensity and frequency resulted in similar effects on increases in back extensor strength.

Adolescent↗

PubMed2005

Attachment types of the long head of the biceps tendon to the glenoid labrum and their relationships with the glenohumeral ligaments.

PURPOSE: To clarify the attachment types of the long head of the biceps tendon to the glenoid labrum and their relationships with the glenoid attachment of the glenohumeral ligaments. TYPES OF STUDY: Anatomic study in cadavers. METHODS: Using 101 cadaver shoulders, the glenoid attachment types of the biceps tendon and the location of the glenoid origin of the glenohumeral ligaments were assessed macroscopically and then histologically on the sagittal section. RESULTS: The glenoid attachment types of the biceps tendon were defined as entirely-posterior in 28 shoulders (27.7%), posterior-dominant in 56 shoulders (55.4%), equal in 17 shoulders (16.8%), and entirely anterior in none (0%). In all shoulders, the superior and middle glenohumeral ligaments were attached between 12 and 1 o'clock (average, 12:36 o'clock), whereas the inferior glenohumeral ligament (IGHL) showed greater variation. In the posterior-dominant and equal types, the IGHL was attached relatively high (average 2:49 o'clock for the posterior-dominant type and 1:49 o'clock for the equal type). In the entirely posterior type, the IGHL was attached low, between 4 and 5 o'clock (average, 4:32 o'clock). There was a significant difference between them (P < .001). Histologic examination showed that in the posterior-dominant and equal types, the fibers of the IGHL directly linked to the fibers of the biceps tendon, whereas in the entirely posterior type no such direct connections were observed. However, in all types, the fibers of the biceps tendon were attached to the posterior labrum. CONCLUSIONS: The labral attachment of the long head of biceps tendon was posterior regardless of its macroscopic appearance. The macroscopic attachment pattern of the biceps tendon resulted from the different attachment height of the IGHL. The attachment site of the IGHL is lower than 4 o'clock in the entirely posterior type, whereas it is higher than 4 o'clock in other types. CLINICAL RELEVANCE: The present study provides useful information about the original attachment site of the IGHL during Bankart repair.

Anthropometry↗

PubMed2005

Cross-sectional area of the tendon and the muscle of the biceps brachii in shoulders with rotator cuff tears: a study of 14 cadaveric shoulders.

BACKGROUND: The intraarticular portion of the long head of the biceps tendon is often widened in shoulders with cuff tears. It is unclear whether this is a local phenomen or is caused by muscle hypertrophy. METHODS: We investigated morphological changes of the biceps brachii in 14 embalmed shoulders: 7 with intact rotator cuff and 7 with rotator cuff tears. We measured the cross-sectional area (CSA) of the tendon of the long head of the biceps (LHB) at 9 levels between the glenoid origin and the musculotendinous junction. The muscle volume and the muscle fiber length of the long and short heads of the biceps were measured to calculate the physiological CSA (PCSA) by dividing the volume by the fiber length. RESULTS: The CSA of the LHB tendon at the entrance to the bicipital groove was greater in cuff tear shoulders than in normal shoulders. The PCSA of the biceps was similar in normal and cuff tear shoulders. INTERPRETATION: Hypertrophy of the LHB tendon appears to be a localized morphological change near the entrance to the bicipital groove.

Aged↗

PubMed2005

The relationship between cardiac output measured by the thermodilution method and that measured by the carbon dioxide rebreathing technique during laparoscopic surgery.

Carbon dioxide insufflation during laparoscopic surgery may interfere with the accuracy of the cardiac output value measured by the NICO2 system. The authors simultaneously measured cardiac output by the thermodilution method and by the carbon dioxide rebreathing technique during laparoscopic adrenalectomy in a patient with a nonfunctional adrenal tumor. There was a strong correlation between the cardiac output values measured by the two methods. This case report suggests that the carbon dioxide rebreathing technique can be used to monitor cardiac output during laparoscopic surgery.

Aged↗

PubMed2005

Determining the plasma concentration of ketamine that enhances epidural bupivacaine-and-morphine-induced analgesia.

N-methyl-D-aspartate (NMDA) receptor antagonists enhance opioid-induced analgesia. The plasma concentration of ketamine, an NMDA receptor antagonist that enhances epidural morphine-and-bupivacaine-induced analgesia, is not known. We examined 24 patients with lung carcinoma or metastatic lung tumor who underwent video-assisted thoracic surgery in a placebo-controlled, double-blind manner 4 h after emergence from anesthesia. The morphine + ketamine group (n = 8) and morphine + placebo group (n = 8) received 5 mL volume of 2.5 mg morphine and 0.25% bupivacaine and the placebo + ketamine group (n = 8) received 5 mL volume of saline and 0.25% bupivacaine epidurally at the end of skin closure. Four hours after this anesthesia, in the morphine + ketamine and placebo + ketamine groups, ketamine was administered to successively maintain a stable plasma ketamine concentration of 0, 10, 20, 30, 40, and 50 ng/mL by a target-controlled infusion device, and patients assessed the levels of pain at rest, pain on coughing, somnolence (drowsiness), and nausea using a 100-mm visual analog scale (VAS). In the morphine + placebo group, a placebo (saline) was similarly administered instead of ketamine. In the morphine + ketamine group, the VAS scores for pain at rest and pain on coughing significantly decreased on ketamine administration at a plasma concentration of 20 ng/mL or larger compared with the respective baseline VAS scores (P < 0.05 each). In the placebo + ketamine group, the VAS scores for pain at rest and pain on coughing did not significantly change at any plasma concentration of ketamine as compared to the morphine + placebo group. In the morphine + ketamine group, a plasma concentration of ketamine larger than 20 ng/mL did not further reduce VAS scores for pain at rest and pain on coughing. The VAS scores for drowsiness were comparable among the three groups at any plasma concentration of ketamine. Ketamine at a plasma concentration of 20 ng/mL or larger may enhance epidural morphine-and-bupivacaine-induced analgesia. As an adjunct with epidural morphine-and-bupivacaine and considering the safety of small doses, the minimal plasma concentration of ketamine given IV may be approximately 20 ng/mL.

Adult↗

PubMed2005

Novel dural closure technique using polyglactin acid sheet prevents cerebrospinal fluid leakage after spinal surgery.

OBJECTIVE: Extradural or subcutaneous cerebrospinal fluid (CSF) leakage is a common complication after spinal surgery and is associated with the risks of poor wound healing, meningitis, and pseudomeningocele. Numerous methods to prevent postoperative CSF leakage are available, but pressure-tight dural closure remains difficult, especially with synthetic surgical membranes. The efficacy of a novel dural closure technique was assessed by detecting extradural or subcutaneous CSF leakage on magnetic resonance imaging. METHODS: The novel dural closure technique using absorbable polyglactin acid sheet and fibrin glue and the conventional procedure using only fibrin glue were evaluated retrospectively by identifying extradural or subcutaneous CSF leakage on magnetic resonance imaging scans in the acute (2-7 d) and chronic (3-6 mo) postoperative stages after spinal intradural surgery in 53 patients. RESULTS: The incidence of extradural and subcutaneous CSF leakage was significantly lower (P < 0.05) in the acute (20%) and chronic (0%) stages using polyglactin acid sheet and fibrin glue in 15 patients compared with that in the acute (81%) and chronic (24%) stages using only fibrin glue in 38 patients. One patient in the fibrin glue-only group required repair surgery for cutaneous CSF leakage. CONCLUSION: The combination of polyglactin acid sheet and fibrin glue can achieve water-tight closure after spinal intradural surgery and can minimize the risk of intractable postoperative CSF leakage. This simple, economical technique is recommended for dural closure after spinal intradural surgery.

Adolescent↗

PubMed2005

Blood loss estimation during laparoscopic myomectomy using HemoCue.

During laparoscopic myomectomy, it is difficult to determine the actual blood loss volume because physiological saline is used for lavaging to detect the bleeding point or to ensure no active bleeding site. We attempted to estimate blood loss by measuring the waste irrigation fluid's hemoglobin (Hb) concentration using HemoCue (HemoCue, Angelholm, Sweden). Twenty-three women enrolled in our study. After the end of laparoscopic myomectomy, the waste irrigation fluid's Hb content was measured using HemoCue. We estimated blood loss using the following formula. Estimated blood loss (ml)= [waste irrigation fluid volume (ml)]x[Hb concentration in waste irrigation fluid (g/l)]/[patient's preoperative Hb level (g/l)]. The demographic data of the patients showed 35.4 years in age, 159.6 cm in height, and 50.7 kg in weight (mean). The total lavage fluid's Hb level ranged between 0.2 approximately 4.7 (g/l). The total blood loss estimation was calculated and ranged between 17.6 approximately 725.2 ml. There was no significant correlation between the calculated blood loss and the difference in Hb level (Hb level on the first postoperative day minus preoperative Hb level). The HemoCue needs only 10 mcl of blood and it takes only about 45 seconds to produce the result. Furthermore, the HemoCue is a reliable device for measurement of blood hemoglobin concentration. Our method is easy and quick to perform, and blood loss estimation and surgeon's experience (subjective method) show accordance.

Blood Loss, Surgical↗

PubMed2005

A case of cervical spondylitis during stellate ganglion block.

We report a case of cervical spondylitis that developed during treatment with a series of stellate ganglion blocks. A 65-year-old man was scheduled for 10 sessions of stellate ganglion block for treatment of right-sided deafness of sudden onset due to Ramsay Hunt syndrome. Administration of betamethasone was started 5 days before the first block and was continued for 6 weeks. After disinfection of the skin by povidone iodine, each stellate ganglion block was performed via the paratracheal approach. The first four block sessions were uneventful. However, during the fifth session, the patient complained of neck pain. After 10 sessions, the deafness improved and the patient was discharged from the hospital. Three weeks after discharge, he was readmitted for sustained neck and bilateral shoulder pain and numbness of the right hand. Cervical roentgenography and magnetic resonance imaging revealed spondylitis of C5 and C6. Antibiotics were administered for 2 weeks. The inflammatory variables on blood examination improved, but cervical roentgenography performed 8 weeks after the last block showed that the vertebral body of C6 was nearly completely destroyed. Four months after the last block, the vertebral bodies of C5 and C6 had fused. This case indicates that when stellate ganglion block is performed in patients who are taking a corticosteroid, the disinfection procedure must be strictly followed and that if the patient complains of neck or shoulder pain, cervical roentgenography or magnetic resonance imaging or both should be immediately performed to assess the presence of spondylitis.

Aged↗

PubMed2005

Blood concentration of propofol in a patient with delayed emergence from propofol-nitrous oxide anesthesia.

We measured the blood concentration of propofol in a patient with delayed emergence from propofol-nitrous oxide anesthesia. A 78-year-old man underwent subtotal gastrectomy under both epidural and propofol-nitrous oxide anesthesia and did not regain consciousness soon after termination of propofol infusion. Preoperative laboratory examination revealed anemia and a low blood total protein concentration, but there was no evidence of impaired liver function. While the anesthesiologists were waiting for the patient to regain consciousness, a surgeon mentioned that the common hepatic artery might have been occluded during surgical manipulation. Arterial blood samples were obtained 50 and 80 minutes after termination of propofol infusion, and the blood concentration of propofol was measured. We considered that clearance of propofol through the hepatic route may have been impaired; however, the actual blood concentrations of propofol were not significantly increased compared with the respective blood concentrations obtained in the simulation. Therefore, the acute liver damage did not significantly impair elimination of propofol. Because most propofol molecules in the blood bind to proteins and erythrocytes, it is suspected that the anemia and low blood total protein concentration led to an increase in the free fraction of propofol in the blood, thereby delaying emergence from anesthesia.

Aged↗

PubMed2005

Effect of bicarbonated Ringer's solution on the acid-base balance in patients undergoing abdominal aortic aneurysm repair.

AIM: The present study was designed to assess whether prophylactic use of bicarbonated Ringer's solution ameliorates metabolic acidosis in patients undergoing aortic surgery. METHODS: Twenty patients undergoing elective infrarenal aortic aneurysm repair were randomly assigned to receive either bicarbonated Ringer's solution or acetated Ringer's solution. The pH, PaCO(2), and base excess (BE) were measured before surgical incision (T0), 5 min before reperfusion (T1), 5 min after reperfusion (T2), and 30 min after reperfusion (T3). Data were compared between the two groups. RESULTS: Both pH and BE initially showed a slight decrease in both groups during clamping. After unclamping of the aorta, an additional decrease in pH was observed in both groups (T0 to T2, and T3). There were no significant differences in pH between the groups throughout the study period. CONCLUSIONS: Aortic cross-clamping leads to the development of metabolic acidosis, with a decrease in pH and BE. The effect of administration of bicarbonated infusion fluid during elective abdominal aortic surgery had not significant compared with that of acetated Ringer's solution with respect to acid-base homeostasis.

Acid-Base Equilibrium↗

PubMed2005

Clinical application of acceleration sensor to detect the swing phase of stroke gait in functional electrical stimulation.

Functional electrical stimulation (FES) can improve the gait of stroke patients by stimulating the peroneal nerve in the swing phase of the affected leg, causing dorsiflexion of the foot that allows the toes to clear the ground. A sensor can trigger the electrical stimulation automatically during the stroke gait. We previously used a heel sensor system, which detects the contact pressure of the heel, in FES to correct foot drop gait. However, the heel sensor has disadvantages in cosmetics and durability. Therefore, we have replaced the heel sensor with an acceleration sensor that can detect the swing phase based on the acceleration speed of the affected leg, using a machine learning technique (Neural Network). We have used a signal for heel contact in a gait using the heel sensor before training with the Neural Network. The accuracy of the Neural Network detector was compared with a swing phase detector based on the heel sensor. The Neural Network detector was able to detect similarly the swing phase in the heel sensor. The largest difference in timing of the swing phase was less than 60 milliseconds in normal subjects and 80 milliseconds in stroke patients. We were able to correct foot drop gait using FES with an acceleration sensor and Neural Network detector. The present results indicate that an acceleration sensor positioned on the thigh, which is cosmetically preferable to systems in which the sensor is farther from the entry point of the electrodes, is useful for correction of stroke gait using FES.

Adult↗

PubMed2005

The effect of magnetic stimulation on unloaded soleus muscle of rat: changes in myosin heavy chain mRNA isoforms.

This study assessed the potential application and the effectiveness of functional magnetic stimulation (FMS) for preventing skeletal muscle atrophy in adult rats. FMS using magnetic stimulator was performed to rat soleus muscle by placing a round magnetic coil on the back of 3rd-5th lumbar vertebral level at 20 Hz frequency for 60 min/day up to 10 days. A reverse transcriptase-polymerase chain reaction was applied to evaluate relative amounts of mRNAs specific to four myosin heavy chain (MHC) isoforms [MHCIbeta, MHCIIa, MHCIIb, and MHCIId(x)] in rat soleus muscle during contractile activity by magnetic stimulation. Ten-day unloading by hindlimb suspension induced a drastic decrease of MHCIbeta and MHCIIa mRNA expressions, while MHCIIb and MHCIId(x) mRNA was not decreased. The magnetic stimulation resuscitated the down-regulation of the mRNA levels of MHCIbeta and MHCIIa. These results suggest that magnetic stimulation on acute atrophied muscles is useful for preventing the muscle atrophy.

Animals↗

PubMed2005

Ligamentum flavum hematoma in the rigid thoracic spinal segments: case report.

Ligamentum flavum hematoma, a rare cause of spinal nerve root and canal compression, typically occurs in the mobile lumbar spine segments. A thoracic ligamentum flavum hematoma is extremely rare--only one such case of a thoracolumbar (T11-12) lesion has been reported. The thoracolumbar region with its floating ribs, however, is structurally and biomechanically similar to the lumbar spine and its mobility is greater than the higher thoracic levels. To the best of their knowledge, the authors report the first case of a ligamentum flavum hematoma in the region of the rigid thoracic spinal segments with the contiguous rib cage. A symptomatic T9-10 ligamentum flavum hematoma is described in the case of a 66-year-old woman with compensatory thoracic lordosis secondary to the lumbar degenerative kyphosis. The hematoma was removed and the diagnosis was histologically confirmed. The authors speculate that thoracic lordosis might have contributed to the development of the hematoma because the ligamentum flavum and the facet joint were subjected to greater axial stress than in individuals with normal spinal alignment.

Aged↗

PubMed2004

Nodular fasciitis of the finger.

Nodular fasciitis is a benign reactive lesion, often mistaken for a soft tissue sarcoma in clinical practice. Involvement of the finger is very rare and, as a result, in this location the lesion has sometimes been treated by ray amputation because of misdiagnosis. We report on the clinical and histological features of nodular fasciitis in a 30-year-old man who was treated by excisional biopsy. There has been no evidence of local recurrence at the recent follow-up 8 years after surgery. The importance of careful histological examination to avoid radical surgery should be emphasized because marginal excision can provide good results in the treatment of nodular fasciitis.

Adult↗

PubMed2004

Stress fracture of the second metacarpal bone.

Stress fractures are usually encountered in athletes; however, only eight such cases involving the metacarpal bones have been reported in the English literature. We report on the rare case of a 15-year-old female tennis player with a stress fracture of the second metacarpal bone.

Adolescent↗

PubMed2004

Usefulness of tissue doppler imaging for assessing aortic wall stiffness in children with the Marfan syndrome.

The purpose of this study was to assess wall motion velocities of the abdominal aorta using tissue Doppler imaging (TDI) in 12 patients with Marfan syndrome and 30 age-matched normal controls. The patients with Marfan syndrome displayed an increased aortic stiffness index in the abdominal aorta, and significant relationships were observed between wall motion velocities of the abdominal aorta and the aortic stiffness index. Thus, TDI analyzes aortic expansion and contraction velocities and allows the identification of abdominal aortic stiffness in patients with Marfan syndrome.

Adolescent↗