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Biomedical subjects

Tadashi Tanaka

Publications and source records attributed to Tadashi Tanaka.

14 recordsLinked to original sources
PubMed2006

Changes in vertebral wedging rate between supine and standing position and its association with back pain: a prospective study in patients with osteoporotic vertebral compression fractures.

STUDY DESIGN: Prospective consecutive series. OBJECTIVE: To analyze supine and standing radiographs and the association of back pain using subjective pain criteria. SUMMARY OF BACKGROUND DATA: It has been considered that there is little correlation between the degree of collapse of the vertebral body and the level of pain. In previous studies, however, measurements have only been based on supine radiographs. Although there were 2 authors who reported the results of supine lateral and standing lateral radiographs in patients with thoracolumbar vertebral fractures, as far as we know, there has not been any detailed report concerning the correlation between radiologic findings using supine and standing lateral radiographs and back pain. METHODS: We examined 100 consecutively treated patients, prospectively. Back pain and the supine and standing radiographs were assessed 1 month after injury. Changes in vertebral wedging rate (WR) from supine to standing position (Delta WR) was reported by the following equation: Delta WR = WR(standing)-WR(supine). RESULTS: The median age of the cohort was 75 years (range, 60-89 years). The median VAS of back pain at supine position, at standing position, and when standing erect was 13, 33, and 41, respectively. The median wedging rate on the supine and standing radiographs were 28% and 37%, respectively (P < 0.001). There was a significant correlation between Delta WR and back pain when standing erect (r = 0.79, P < 0.001). CONCLUSION: Changes in vertebral wedging rate between supine and standing position and its association with back pain may give a clue to the pathogenesis of pain from osteoporotic thoracolumbar vertebral compression fractures.

Aged↗
PubMed2006

The treatment of acute thoracolumbar burst fractures with transpedicular intracorporeal hydroxyapatite grafting following indirect reduction and pedicle screw fixation: a prospective study.

STUDY DESIGN: Prospective consecutive series. OBJECTIVE: To evaluate the outcomes of the treatment of acute thoracolumbar burst fractures by transpedicular hydroxyapatite grafting following indirect reduction and pedicle screw fixation. SUMMARY OF BACKGROUND DATA: In the treatment of thoracolumbar burst fractures, the major problem after posterior correction and instrumentation is failure to support the anterior spinal column, leading to the loss of correction of kyphosis and instrumentation breakage. METHODS: There were 15 consecutive patients who had thoracolumbar burst fractures and associated incomplete neurologic deficit. They underwent surgery within 4 days of admission, had their implants removed within 1 year, and were prospectively followed for at least 2 years. Following indirect reduction and pedicle screw fixation, transpedicular intracorporeal hydroxyapatite grafting to the fractured vertebrae was performed. Median operating time was 130 minutes, and median blood loss was 155 g. RESULTS: The neurologic function of all 15 patients improved by at least 1 American Spine Injury Association grade, with 9 (60%) having complete neurologic recovery. Sagittal alignment was improved from a median preoperative kyphosis of 20 degrees to -1 degrees (lordosis) by surgery but was found to have slightly deteriorated to 1 degrees at final follow-up observation. Computerized tomography showed a median spinal canal narrowing of 64%, 22%, and 11%, respectively. There were no instances of instrumentation failure. CONCLUSIONS: Posterior indirect reduction, transpedicular hydroxyapatite grafting, and pedicle screw fixation could provide reliable neurologic improvement in patients with incomplete neurologic deficit, and could prevent the development of kyphosis. This technique does not require fusion to a segment, thereby preserves thoracolumbar motion.

Adolescent↗
PubMed2006

Discovery of nonpeptidic small-molecule AP-1 inhibitors: lead hopping based on a three-dimensional pharmacophore model.

We designed and synthesized small-molecule activator protein-1 (AP-1) inhibitors based on a three-dimensional (3D) pharmacophore model that we had previously derived from a cyclic decapeptide exhibiting AP-1 inhibitory activity. New AP-1 inhibitors with a 1-thia-4-azaspiro[4.5]decane or a benzophenone scaffold, which inhibit the DNA-binding and transactivation activities of AP-1, were discovered using a "lead hopping" procedure. An additional investigation of the benzophenone analogues confirmed the reliability of the pharmacophore model, its utility to discover AP-1 inhibitors, and the potency of the benzophenone derivatives as a lead series.

Animals↗
PubMed2006

[Leak of anesthetic gases inside the anesthesia machine].

We experienced the leak of anesthetic gases inside the anesthesia machine in spite of performing the leak test before its use. After induction of anesthesia, a laryngeal mask airway was inserted and the patient was ventilated manually. At the beginning we could not find any signs of machine troubles. High airway pressure occurred immediately after switching to the mechanical ventilation. Because we could not detect the details of the machine trouble, tidal volume was set lower and the surgery was continued. After surgery, we found a crack in a fresh gas circuit valve. We have to check the anesthesia machine regularly and know its duration of use.

Anesthesia, Closed-Circuit↗
PubMed2005

Patients' expectations and satisfaction in lumbar spine surgery.

STUDY DESIGN: Prospective consecutive series. OBJECTIVE: To determine patient expectations in lumbar spine surgery and assess the level of fulfillment of those expectations. SUMMARY OF BACKGROUND DATA: Little has been offered in the literature in specific regards to lumbar spine surgery. METHODS: Ninety-eight patients, 49 patients who underwent discectomy for lumbar disc herniation (Group 1) and 49 patients who underwent laminotomy for lumbar spinal stenosis (Group 2), completed the self-report questionnaire. Preoperative expectations, reasons for surgery, and expected postoperative status were inquired before surgery and the satisfaction at 2 years after surgery. RESULTS: Concerning patients' expectations, half of the patients expected to become completely leg pain free, and more than three fourths of the patients expected to become unlimited in their walking ability in both groups. More than half of the patients expected to have a 90% or greater chance of complete success of surgery. With regard to satisfaction, 42 of the 49 patients (86%) in Group 1 and 35 of the 49 patients (71%) in Group 2 chose "Surgery met my expectations" at the follow-up. The remaining patients selected "I did not improve as much as I had hoped." Positive expectations were associated with better satisfaction in Group 1 only. Of the patients who had achieved the expected postoperative status with respect to their no.1 reason for surgery, 2 of 34 patients in Group 1 (6%) and 5 of the 26 patients in Group 2 (19%) nonetheless reported "unfulfilled expectations." In patients whose no. 1 concern was further progression, 3 (38%) of the 8 patients in Group 1 and 2 (40%) of the 5 patients in Group 2 demonstrated unfulfilled expectations. CONCLUSIONS: Even if the clinical expectations were met, some patients were still dissatisfied. Patients with spinal stenosis (Group 2) seem to have more unrealistic expectations than patients with disc herniation (Group 1).

Adult↗
PubMed2005

Anatomic changes in lateral spondylolisthesis associated with adult lumbar scoliosis.

STUDY DESIGN: Prospective consecutive series. OBJECTIVE: To analyze the anatomic changes in lateral spondylolisthesis. SUMMARY OF BACKGROUND DATA: Previous studies have focused on the correlation between lateral spondylolisthesis, and curve progression and pain. To our knowledge, there has not been any detailed report concerning anatomic changes in lateral spondylolisthesis. METHODS: We examined 24 consecutive patients (mean age 66 years), with lateral spondylolisthesis associated with lumbar scoliosis who had computerized tomography (CT) after myelography. Coronal reconstruction CT was used to measure the vertebral translation. Vertebral rotation was measured by the Aaro method using transaxial CT. RESULTS: The Cobb angle averaged 26 degrees (range 13 degrees-75 degrees). Lateral spondylolisthesis was found most commonly at the lower-end vertebra. The cephalad-slipped vertebra rotated toward the convex side of the main curve, whereas the caudal vertebra rotated toward the convex side of the lumbosacral hemi (or fractional) curve below. Mean lateral translation and vertebral rotation were 7 mm and 8 degrees, respectively. There was a significant correlation between lateral translation and vertebral rotation (r = 0.49; P = 0.018). The convex superior articular process of the caudal vertebra had compressed the nerve root laterally in 21 patients, of whom 10 had radicular pain. The concave, inferior articular process of the cephalad vertebra had compressed the dural sac posteriorly, and 2 patients had radicular pain. CONCLUSIONS: To our knowledge, this study has been the first attempt to analyze anatomic changes in lateral spondylolisthesis using CT. It may offer further insight into the pathogenesis of adult lumbar scoliosis.

Aged↗
PubMed2005

Insulin secretion and glucose utilization are impaired under general anesthesia with sevoflurane as well as isoflurane in a concentration-independent manner.

PURPOSE: The dose-dependent effects of sevoflurane and isoflurane anesthesia on glucose tolerance were compared in humans. METHODS: A prospective, randomized clinical study was conducted in 30 patients. The 30 patients were divided randomly into three sevoflurane anesthesia groups (0.5, 1.0, and 1.5 minimum alveolar concentration [MAC]) and three isoflurane anesthesia groups (0.5, 1.0, and 1.5 MAC). Induction of anesthesia was accomplished by inhalation of the volatile agent and nitrous oxide. After induction, anesthesia was maintained at the designated MAC for 15 min without surgical stimulation. The intravenous glucose tolerance test (IVGTT) was performed in these 30 patients while they were under general anesthesia and again several days after surgery in 5 of these patients while they were awake, as a control. RESULTS: The insulinogenic index (change in concentration of immunoreactive insulin/change in glucose concentration), the acute insulin response, and rates of glucose disappearance were significantly lower in all anesthesia groups than in the control group. However, the insulinogenic index, acute insulin response, and the glucose disappearance rate did not differ significantly among the six anesthesia groups. CONCLUSION: Sevoflurane anesthesia impairs glucose tolerance to the same degree as does isoflurane anesthesia. Glucose intolerance during sevoflurane or isoflurane anesthesia is independent of agent and dosage up to 1.5 MAC.

Anesthesia, General↗
PubMed2004

Low-back pain following surgery for lumbar disc herniation. A prospective study.

BACKGROUND: Lumbar disc herniation often causes sciatica. Although surgery may provide relief of sciatic pain, it is uncertain how surgery affects the relief of low-back pain. The purpose of the present prospective study was to assess the efficacy of discectomy in the treatment of low-back pain associated with lumbar disc herniation. METHODS: Between 1998 and 2001, forty consecutive patients with single-level, unilateral lumbar disc herniation were treated surgically. The first twenty patients (Group 1) underwent standard discectomy, and the second twenty (Group 2) underwent microendoscopic discectomy. Curettage of the disc space was not performed. All forty patients were prospectively followed, and clinical outcomes were evaluated with use of a questionnaire. The mean duration of follow-up was forty months. RESULTS: All forty patients were satisfied with the outcome. Leg pain decreased rapidly (within one month) in all patients and continued to decrease at the time of the latest follow-up. There was no significant difference between the two groups in terms of leg pain, with the numbers available (p = 0.39). A significant decrease in the mean low-back pain score was noted at the time of the latest follow-up (p = 0.0007). CONCLUSIONS: Excision of a herniated disc for relief of sciatica provided rapid relief of sciatica and low-back pain. The findings of the present small study suggest that lumbar disc herniation might be a possible cause of low-back pain.

Adolescent↗
PubMed2004

Excision repair cross complementing 3 expression is involved in patient prognosis and tumor progression in esophageal cancer.

The prognosis of patients with esophageal cancer remains poor. TNM classification is not sufficient to predict the prognosis. Therefore, novel predictive markers of the prognosis of esophageal cancer patients are awaited. The abnormality of the nucleotide excision repair (NER) is often involved in human cancers. Excision repair cross complementing 3 (ERCC3) contributes to NER. In esophageal cancer, ERCC3 expression has not been studied. Expression of ERCC3 was quantified by real-time reverse transcription polymerase chain reaction (RT-PCR) using LightCycler in 43 primary esophageal squamous cell carcinomas (ESCCs) and their paired normal esophageal mucosa. We examined the correlation between the ERCC3 expression and the clinicopathological factors and prognosis of ESCC patients. ERCC3 expression level was significantly correlated with the pathologic stage, tumor size and local invasiveness (t-factor) in esophageal cancer tissues. Reduced expression of ERCC3 was accompanied with tumor progression (p=0.0049) and higher pathologic stage (p=0.020). Moreover, ESCC patients with low ERCC3 mRNA expression had significantly shorter post-operative survival time than those with high expression (p=0.0003). In esophageal cancer, reduced expression of ERCC3 was correlated with local tumor progression and poor prognosis after operation.

Aged↗
PubMed2003

Trauma care systems in Japan.

The trauma care system in Japan was set up in the 1960s in response to social problems caused by traffic accidents and has since been altered extensively. First-aid and patient transfer are performed by emergency personnel belonging to a fire station. Instead of 'western-style trauma centres', three types of facilities exist: (1) primary emergency care facilities for treating mild cases not requiring hospitalisation; (2) secondary emergency hospitals directed to treating moderately severe disease or injury; (3) tertiary emergency hospitals corresponding to the emergency departments of university hospitals, or lifesaving emergency centres, able to manage the most severe cases such as myocardial infarction, cerebrovascular accident and polytrauma. Although the quantity of emergency facilities and hospitals appears sufficient, the quality of emergency care needs to be improved. This could be accomplished by the unification of small hospitals to create larger hospitals, and/or by the establishment of trauma centres, as well as by improvements in relevant education and training.

Accidents, Traffic↗
PubMed2003

Variations in transpiration rate and leaf cell turgor maintenance in saplings of deciduous broad-leaved tree species common in cool temperate forests in Japan.

To clarify mechanisms underlying variation in transpiration rate among deciduous broad-leaved tree species, we measured diurnal changes in stomatal conductance (gs) and leaf water potential, and calculated the maximum transpiration rate (Emax), leaf-specific hydraulic conductance (K(s-l)) and difference between the soil water potential and the daily minimum leaf water potential (Psis - Psi(l,min)). Pressure-volume (P-V) measurements were made on leaves. Saplings of eight broad-leaved tree species that are common in Japanese cool temperate forests were studied. Maximum transpiration rate varied significantly among species. There was a statistically significant difference in Psis - Psi(l,min), but not in K(s-l). Species with large Emax also had large Psis - Psi(l,min) and gs. The results of the P-V analyses showed that species with a large Psis - Psi(l,min) maintained turgor even at low leaf water potentials. The similar daily minimum leaf pressure potentials (Psip) across all eight species indicate that Psip values below this minimum are critical. Based on these results, we suggest that the leaf cell capacity for turgor maintenance strongly affects Psis - Psi(l,min) and consequently Emax via stomatal regulation.

Betula↗
PubMed2003

[AO classification of fractures].

In the AO classification, the diagnosis of a fracture is expressed by its location (bone and segment) and morphological features, which is characterized by the hierarchical organization into triad. This classification is comprehensive and very useful in a daily clinical practice.

English Abstract↗
PubMedDate not supplied

Ocular discomfort at the initial wearing of rigid gas permeable contact lenses.

PURPOSE: To evaluate the relationship between ocular discomfort in the initial wearing of rigid gas permeable contact lenses (RGPCL) and the time required to adapt to RGPCL as measured by using the visual analogue scale (VAS). METHODS: RGPCL were prescribed for 89 patients (178 eyes) with myopia or myopic astigmatism and no history of wearing contact lenses. The patients who stopped wearing RGPCL after 1 week because of ocular discomfort were defined as dropouts, and those who adapted to regular full-time RGPCL wear were defined as successful wearers. VAS scores were measured at several intervals for 1 month after the initial wearing of the lenses. The number of days required to adapt to wearing RGPCL was defined as the adaptation time. RESULTS: Four patients were dropouts due to ocular discomfort (eight eyes; 4.5%). VAS scores were significantly lower in successful wearers than in dropouts at 1 week, although their VAS scores were not different at 1 day. VAS scores of the successful wearers at 1 week were significantly lower than those at 1 day. The average time required to adapt to RGPCL was 23.0 +/- 22.1 days for the 85 successful wearers. Lower VAS scores at 1 day or 1 week were significantly correlated with a shorter adaptation time in the successful RGPCL wearers. CONCLUSIONS: Our results indicate that the VAS score might be useful for predicting successful RGPCL use and the adaptation time required by successful wearers.

Adaptation, Ocular↗