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Biomedical subjects

S Tamai

Publications and source records attributed to S Tamai.

At least 19 recordsLinked to original sources
PubMed1999

Sleep complaints among the elderly: results from a survey in a psychogeriatric outpatient clinic in Brazil.

BACKGROUND: Sleep complaints are frequent in old age. These difficulties are often associated with health-related problems, drug consumption, and the presence of mental disorders. Nonetheless, only sparse information is available on the clinical characteristics of elderly persons with insomnia. AIMS: (a) To evaluate the prevalence of sleep problems among the elderly assessed in a psychogeriatric outpatient clinic; (b) to evaluate the association between the use of sleep tablets and sleep difficulties in this sample of patients. METHODS: One hundred eighteen consecutive subjects were recruited from a psychogeriatric outpatient service in São Paulo, Brazil. Their sleep pattern was systematically assessed with the "sleep inventory," a questionnaire consisting of 31 items that evaluate a number of sleep-related features. Clinical diagnoses followed the ICD-10 clinical descriptions and diagnostic guidelines. The number of drugs consumed by patients was also recorded. RESULTS: Sleep complaints were highly prevalent (59.3%), with early-morning awakening and nightmares being more frequent among patients with a depressive disorder. The use of sleep tablets was reported by 37.3% of subjects, and was associated with subjective sleep difficulties (odds ratio [OR] = 7.13, p = .008), difficulties falling asleep (OR = 7.33, p = .021), and frequent awakening during the night (OR = 7.10, p = .040) in a logistic regression analysis. CONCLUSION: Sleep dissatisfaction is frequent among psychogeriatric outpatients. Subjects taking hypnotic drugs have more sleep-related complaints than those who do not. The clinical use of hypnotics may not be very effective for the treatment of sleep-related problems in the elderly. There is an urgent need for systematic prospective controlled studies to assess the efficacy and safety of the various forms of treatment of insomnia in old age.

Aged↗
PubMed1999

Clear cell change in colorectal adenomas: its incidence and histological characteristics.

AIMS: The aim of our investigation was to clarify the histological characteristics and biological significance of clear cell change in colorectal adenomas. METHODS ANID RESULTS: We found three cases (0.086%) of tubular adenomas with clear cell change in a review of 3486 cases of colorectal adenoma. These three cases occurred in male patients and were located in the left-sided colon. To investigate the nature and biological significance of the clear cells, we conducted histochemical staining (periodic acid-Schiff (PAS) with or without diastase digestion, alcian blue pH 2.5) and immunohistochemical staining (using antibodies against carcinoembryonic antigen (CEA), alpha-fetoprotein, p53 protein and Ki67 antigen) and also mitotic counts. Histologically, the changed area was characterized by pyknotic and randomly arranged nuclei with PAS-negative clear and vacuolated cytoplasm. Immunoreactivity for CEA was diffuse and strong in the clear cells, but not in the tumour cells in the ordinary portion of the adenomas. The Ki67 labelling index and the mitotic activity were both higher in the clear cell portion than in the ordinary portion. CONCLUSIONS: This is the first study to indicate the incidence of clear cell change among colorectal adenomas. It has confirmed high proliferative activity within the clear cell portion of colorectal adenomas.

Adenoma↗
PubMed1999

Long-term results of arthrodesis for osteoarthritis of the ankle.

A bone graft in the shape of a triangular prism was taken from the anterior surface of the tibia and used in the arthrodesis in 43 joints of 42 patients with primary and secondary osteoarthritis of the ankle. The modified anterior sliding inlay graft method was used. The average period of external immobilization was 5.8 weeks (range, 27-84 days), and followup ranged from 2 years 4 months to 14 years 11 months (average, 7 years 2 months). Nonunion was detected in three (7%) patients: one patient returned to work without additional treatment, and the other two patients underwent followup surgery within 7 months, and bony union was achieved. The final rate of nonunion was 2.3%. After the operation, excellent alleviation of pain was obtained. However, dorsiflexion of the foot decreased from the preoperative average value of 10.5 degrees to the postoperative value of 4.2 degrees, and plantar flexion also decreased from the preoperative value of 24.7 degrees to the postoperative value of 14 degrees. In addition, the range of motion of the subtalar and Chopart joints gradually improved with little effect on daily living activities. The most appropriate position of arthrodesis of the ankle appears to be in the neutral position between dorsal and plantar flexion. In addition, the varus and valgus angle of the hindfoot should be in a neutral or slightly valgus position. Degenerative arthritis developed and advanced in the subtalar joint in 32.5% of the patients, and these degenerative changes were exacerbated in many patients if such changes were present before surgery. Tibial stress fracture occurred in two (4.7%) patients as a complication that was specific to the current surgical method. Thus, the surgical procedure was modified to prevent the onset of tibial stress fracture.

Activities of Daily Living↗
PubMed1999

[Expert systems and automatic diagnostic systems in histopathology--a review].

In this decade, the pathological information system has gradually been settled in many hospitals in Japan. Pathological reports and images are now digitized and managed in the database, and are referred by clinicians at the peripherals. Tele-pathology is also developing; and its users are increasing. However, in many occasions, the problem solving in diagnostic pathology is completely dependent on the solo-pathologist. Considering the need for timely and efficient supports to the solo-pathologist, I reviewed the papers on the knowledge-based interactive expert systems. The interpretations of the histopathological images are dependent on the pathologist, and these expert systems have been evaluated as "educational". With the view of the success in the cytological screening, the development of "image-analysis-based" automatic "histopathological image" classifier has been on ongoing challenges. Our 3 years experience of the development of the pathological image classifier using the artificial neural networks technology is briefly presented. This classifier provides us a "fitting rate" for the individual diagnostic pattern of the breast tumors, such as "fibroadenoma pattern". The diagnosis assisting system with computer technology should provide pathologists, especially solo-pathologists, a useful tool for the quality assurance and improvement of pathological diagnosis.

Expert Systems↗
PubMed1999

Marrow cell culture on poly-L-lactic acid fabrics.

Bone marrow cells from rat femurs were cultured in Eagle Minimum Essential Medium containing 15% fetal calf serum until confluence. After the cells were trypsinized, they were subcultured on fabrics made of biodegradable poly-L-lactic acid for 2 weeks in the medium containing fetal calf serum, ascorbic acid phosphate, beta-glycerophosphate, and with and without dexamethasone. In the presence of dexamethasone, the fabrics showed many mineralized nodules together with cuboidal shaped cells that had osteoblastic activity, as evidenced by high alkaline phosphatase activity and the appearance of osteocalcin messenger ribonucleic acid. However, in the absence of dexamethasone, nodules did not form and many fibroblastic cells appeared with no evidence of osteoblastic activity. These results indicate the possibility of making a hybrid ligament substitute having an in vitro prefabricated bone anchor.

Alkaline Phosphatase↗
PubMed1998

Analysis of gene expression in osteogenic cultured marrow/hydroxyapatite construct implanted at ectopic sites: a comparison with the osteogenic ability of cancellous bone.

We investigated the in vivo osteogenic ability of cultured marrow cells subcultured in porous hydroxyapatite. This osteogenic ability was compared with that of cancellous bone grafts. Fresh marrow cells were obtained from young adult rat femora and cultured in a standard medium for 10 days, then trypsinized and used to make constructs of porous hydroxyapatite (HA) and cultured marrow cells. An additional 2-week culture (subculture) was performed for the construct in standard medium with and without the addition of dexamethasone (Dex). The 2-week subcultured constructs then were implanted into subcutaneous sites of syngeneic rats. These implants and the rat cancellous bone were harvested and prepared for gene expression analysis of alkaline phosphatase (ALP) and osteocalcin (OC) as well as for histological analysis. ALP and OC mRNAs could be detected in Dex-treated subcultured constructs 1 week after implantation with an increase at 2 weeks, comparable to the observation in cancellous bone. Histological analysis showed active bone formation even 1 week postimplantation. In contrast, the subcultured constructs without the addition of Dex did not show bone formation, and only small levels of ALP and OC mRNAs were found. These results indicate that the bone tissue formed by grafting the Dex-treated construct of cultured marrow cells and hydroxyapatite possesses a high osteoblastic activity comparable to that of viable cancellous bone. Thus the prefabricated osteogenic subcultured marrow/HA construct may be applicable in bone reconstructive surgery.

Alkaline Phosphatase↗
PubMed1998

Heterogeneous pattern of gene expression in cloned cell lines established from a rat transplantable osteosarcoma lung metastatic nodule.

We have established three cloned cell lines (COS1NR, COS2NR and COS4NR) from the lung metastatic nodule of a highly metastatic variant of rat transplantable osteosarcoma, C-SLM. All three clones shared the same morphological characteristics and tumorigenicity, but their growth rates in vitro and metastatic ability in vivo differed from each other. Single-strand conformation polymorphism (SSCP) analysis revealed all three clones to have the same p53 gene mutation and parent C-SLM tumor. On the other hand, Northern blot analysis showed a different pattern of expression for the genes, c-fos, c-jun, c-Ha-ras, transin (rat stromelysin), bone Gla protein (osteocalsin) and nm23/NDP kinase. These results indicate the presence of a heterogeneous cell population in terms of the different pattern of gene expression in a lung metastatic nodule of rat osteosarcoma and the present newly established cell lines will be useful for further investigation of the biological behavior of osteosarcomas.

Animals↗
PubMed1998

Axial alignment of the lower limb in patients with isolated meniscal tear.

Meniscal tears do not always result from trauma. To elucidate other factors responsible for meniscal tears, we evaluated the axial alignment of the lower limb in 385 patients (385 menisci) with isolated meniscal tear who were examined between 1972 and 1994. The patients were aged 50 years or less and had no ulceration or defect of articular cartilage of the knee when examined arthroscopically. Of the 385 menisci, 90 were lateral complete discoid; 110, lateral incomplete discoid; 68, lateral semilunar; and 117, medial semilunar. Patients in each of these four groups were divided into four subgroups according to sex and whether there was an obvious history of trauma. The so-called Mikulicz's mechanical axis of the affected side was utilized to evaluate the alignment. The axial alignment of the lower limb was normal in the patients with isolated tears of lateral complete discoid meniscus, lateral incomplete discoid, or lateral semilunar. It appeared that the axial alignment of the lower limb did not have a relationship with the occurrence of these tears. Patients with isolated tears of medial semilunar meniscus without obvious trauma, showed varus deformity of the knee. This deformity appeared to be closely related to the presence of medial meniscal tear.

Adolescent↗
PubMed1998

Morphologic changes in long head of biceps brachii in rotator cuff dysfunction.

Morphologic changes in the long head of the biceps brachii (LHB) and bicipital groove associated with cuff tears were studied in 170 cadavers. In specimens with minimum or moderate cuff tears, the primary finding was relative stenosis at the bicipital groove induced by enlargement of the LHB. However, this stenosis was not apparent in specimens with massive cuff tears and in these specimens, the medial wall of the groove exhibited wear and tear, a potential cause of LHB instability. We suggest that the long head of the biceps brachii muscle can potentially compensate for inadequate rotator cuff function. This increasing activity could lead to enlargement of the tendon and cause deterioration of the bicipital gliding mechanism.

Adult↗
PubMed1998

Subzero nonfreezing preservation in a murine limb replantation model.

This study was designed to examine the most effective temperature for hypothermic storage, without freezing, to prolong ischemic tolerance in an amputated murine hindlimb model. We measured freezing points in the calf muscle and the subcutaneous tissue of the foot in the amputated limbs of Fisher 344 strain male inbred rats. The highest freezing point was -1.5 degrees C, which was recorded in the calf muscle. To prevent freezing in any of the tissues in the amputated limb, the temperature for the lowest nonfreezing preservation was defined as -1 degrees C. The amputated limbs were preserved at subzero nonfreezing temperature (-1 degrees C) and at 4 degrees C for 4, 8, 12, 24, 48, and 72 h, and were then transplanted to other inbred rats by microsurgical techniques. We evaluated the vascular patency of the anastomoses by direct observation and performed histological examinations on the seventh day after replantation. Subzero nonfreezing preservation of a limb at -1 degrees C for 72 h was significantly superior to hypothermic preservation at 4 degrees C for 72 h in terms of anastomotic patency rates (P < 0.05). The histology of skeletal muscles preserved at -1 degrees C for 8 h showed greater similarity to the normal situation than the histology of those preserved at 4 degrees C for 8 h. Bone viability with osteoblastic activity was maintained in grafted limbs preserved at -1 degrees C for 72 h, but in the limbs preserved at 4 degrees C for 72 h the bone was not viable, showing no osteoblastic activity. Clinically, the period of ischemia in major limb replantation at normal ambient temperatures is limited to about 6 h. In this study, the maximum ischemia time for replantation of a limb containing muscle tissue was prolong to 8 h at -1 degrees C, but the maximum ischemia time at 4 degrees C could not be prolonged to 8 h. Our results suggest that, in the major replantation of a limb containing muscular tissue, hypothermic preservation at -1 degrees C would be more useful than preservation at 4 degrees C.

Animals↗
PubMed1998

Detection of cracks in polyethylene components of retrieved knee joint prostheses.

Subsurface cracks that had formed in polyethylene artificial knee components were observed nondestructively with a new method, scanning acoustic tomography (SAT). Standardization of the SAT observation was done by in-vitro rolling fatigue testing on an unimplanted ultra high molecular weight polyethylene (UHMWPE) knee component. Retrieved knee components were of two types; KOM (Kyocera, Kyoto, Japan) sterilized with ethylene oxide gas, and MG (Zimmer, IN, USA) sterilized with gamma-irradiation. The SAT images revealed cracks in all the retrieved components, and these existed mainly 0. 3-1.0 mm from the surface. Comparison of crack formation in each portion of the contact area of the polyethylene components showed that the middle portion of the MG type had the highest concentration of cracks. When the distribution of compressive stress on the polyethylene components was assessed by mechanical testing, the strongest compressive stress was seen in the middle portion of MG type components.

Acoustics↗
PubMed1998

Temporary internal fixation of the scaphotrapezio-trapezoidal joint for the treatment of Kienböck's disease: a preliminary study.

Temporary scaphotrapezio-trapezoidal (STT) fixation with Kirschner wires (K-wires) has been used in the treatment of 16 cases of Kienböck's disease since 1988. Twelve of these cases with a follow-up of at least 1 year were reviewed. Eight patients were women and 4 were men and the average age at the time of surgery was 44 years (range, 20-67 years). Five cases were treated with temporary STT fixation and vascular bundle implantation (group V), and 7 cases were treated with temporary STT fixation and tendon roll implantation (group T). K-wires were removed between 16 and 26 weeks after surgery (average, 18.6 weeks) in group V, and between 8 and 13 weeks (average, 9.7 weeks) in group T. The follow-up periods ranged from 12 to 92 months (average, 38 months). Postoperative wrist pain disappeared in 7 cases and decreased in 5. The postoperative arc of wrist flexion and extension increased from 97 degrees to 108 degrees in group V and from 85 degrees to 103 degrees in group T. Grip strength improved from 22.2 to 30.6 kg in group V and from 11.4 kg to 17.7 kg in group T. X-ray evaluation revealed that the mean carpal height ratio was 0.488 before surgery, 0.489 during STT fixation, and 0.480 at the final follow-up. The carpal height decreased in 3 cases (2 in group V and 1 in group T). The postoperative radioscaphoid angle improved in all cases during K-wire insertion and regressed after removal of the K-wire, eventually showing a decrease in 4 cases, an increase in 3 cases, and no change in 5 cases.

Adult↗
PubMed1998

Histologic findings in polyacrylamide-coated polytetrafluoroethylene (PTFE) arterial grafts in the rat abdominal aorta.

To improve cell attachment without inducing thrombogenesis, the authors coated the inner surface of polytetrafluoroethylene (PTFE) prostheses (I.D.: 1 mm; length: 10 mm; wall thickness: 0.5 mm; fibril length: 30 microm) with polyacrylamide (PAA), known to have a strong antithrombotic effect (PAA-PTFE). They implanted the prostheses into the abdominal aorta of rats, and retrieved them at intervals of up to 9 months. Graft healing was observed under light and scanning electron microscopy. All the inner surfaces of the grafts examined were barely covered with fibrin or platelets. The PAA-coated fibers had many projections, in contrast to the original PTFE prostheses. Neo-endothelium was observed to be directly attached to these structural fibers of the PAA-PTFE grafts. Restoration of the neointima was also observed in these vascular prostheses.

Acrylic Resins↗
PubMed1998

A method for prevention of arterialized venous flap necrosis.

The authors used a delayed arteriovenous (A-V) shunt method to prevent congestion and necrosis of arterialized venous flaps. Two weeks before elevating the flap, an A-V shunt between the central artery and vein was created at the more proximal flap end. Twelve rabbits (24 flaps) were used for this experiment. Flaps were followed for 4 weeks. Twelve of 24 flaps survived completely; another 10 flaps showed partial necrosis; and two flaps became completely necrotic. These results demonstrated that this method is superior to a simple A-V shunt in preventing congestion and necrosis in the arterialized venous flap.

Animals↗
PubMed1998

Electromyographic analysis of shoulder joint function of the biceps brachii muscle during isometric contraction.

Surface electromyography was performed for both heads of the biceps brachii in 11 healthy men while the muscles were under 30% maximum isometric shoulder flexion and abduction. Elbow related biceps activity was minimized by using a brace locked in neutral forearm rotation. Electromyographic activity was normalized as a percentage of maximal muscle contraction during 24 shoulder motions. Electromyographic activity was detected in all motions examined, suggesting that the biceps muscle acts as a flexor and an abductor of the shoulder. Both heads of the biceps muscle had higher activities during external rotation than during internal rotation for most motions. Activities of both heads increased with arm elevation, but showed little dependence on elbow position. The long head was still active during internal rotation of the shoulder. These findings also suggest that the biceps muscle is a flexor and an abductor of the shoulder, and that the long head can act as a humeral head stabilizer in superior and anterior directions. Muscle fatigue of the biceps and the deltoid muscle also was determined at 30% of maximum isometric flexion. All muscles had significantly decreased mean power frequency and turns count, and increased amplitude and integrated electromyography. The rate of decrease in mean power frequency was larger for the biceps than for the deltoid muscle, and the rate of increase in amplitude was larger for the long head of the biceps than for the short head or for the deltoid muscle. These findings suggest that the long head of the biceps must increase its mechanical output to keep the arm in elevation to a greater extent than do the short head and the deltoid muscle. This may be one of the causes of tendinitis or rupture of the long head.

Adolescent↗
PubMed1998

Vascularized bone grafts to the upper extremities.

From 1979 to 1995 in our clinic, vascularized bone grafting was performed in 29 patients with large bone defects, established nonunion, congenital pseudoarthrosis, or avascular necrosis in the upper extremity. Four patients had traumatic bone defects, six had posttraumatic nonunions, two had congenital pseudoarthroses, five had amputations, nine had defects following tumor resection, and three had other lesions. Reconstructed sites were the humerus in 7 patients, the radius in 12, the ulna in 2, both radius and ulna in 1, and the metacarpal and phalangeal bones in 7. Donor bones were fibula in 19 cases, radius in 6, scapula in 2, and medial condyle of the femur in 2. Postoperative circulatory disturbances and venous thrombosis resulted in revision surgery in two patients. Thrombectomy and reanastomosis to other veins were performed, and these flaps took successfully. No patients required additional bone grafts. The mean period required to obtain radiographic bone union was 4 months (fibula, 4.5 months; scapula, 3.5 months; radius, 2.6 months; medial condyle of the femur, 4 months). Vascularized fibula graft is indicated in patients with large bone defects in the humerus, radius, and/or ulna. The scapula is easy to transfer to the proximal humerus on its pedicle. This donor is indicated in young women because operative scars can be hidden. The radius is usually harvested with skin, and its use is indicated in patients with bone loss in the hand including thumb amputations. Thin corticoperiosteal graft from the femur is indicated in patients with established nonunion of the humerus and radius without significant bony defects.

Adolescent↗
PubMed1998

Telomerase activity correlates with growth of transplantable osteosarcomas in rats treated with cis-diammine dichloroplatinum or the angiogenesis inhibitor AGM-1470.

To determine the role of telomerase activity in the growth of tumors in rats undergoing chemotherapy, a comparison of the volumes of telomerase-positive transplantable osteosarcomas was made in rats treated with the antineoplastic agent cis-diammine dichloroplatinum (CDDP) or the angiogenesis inhibitor O-(chloroacetylcarbamoyl)fumagillol (AGM-1470). Male F344 rats, 8 weeks old, received transplants of macroscopic lung metastatic nodules into the subcutaneous back space and treatment was started on day 14 thereafter. CDDP was injected i.v. at doses of 0, 0.625, 1.25 and 2.5 mg/kg body weight (b.w.) and AGM-1470 was administered at total doses of 0, 2.5, 5 and 10 mg/kg b.w. over 2 weeks by osmotic pumps, also implanted into the subcutaneous back space, but remote from the transplanted tumors. On day 28, all animals were killed for measurement of transplanted tumor size and determination of telomerase activities by telomeric repeat amplification protocol (TRAP) assay. The results showed telomerase activity to be highly correlated with the treated/non-treated (T/C) tumor size ratio (r = 0.96, P < 0.0001). In a second experiment, CDDP at 2.5 mg/kg b.w. and AGM-1470 at 10 mg/kg b.w., these being the most effective doses, were given as in the first experiment, and animals were serially killed on days 14, 21, 28, 35 and 42. Tumors in rats treated with CDDP and AGM-1470 showed 18.2% and 20.5% of the control telomerase activity on days 35 and 21, respectively, when tumor growth was inhibited. However, on day 42, the activities increased to 46.5% and 92.5%, this correlating with re-growth (r = 0.73, P < 0.0001). These results suggest that decline of telomerase activity may be involved in tumor growth retardation induced by chemotherapeutic agents. This possibility clearly warrants further mechanistic studies.

Animals↗