Biomedical subjects

S Tamai

Publications and source records attributed to S Tamai.

At least 235 records · Page 13Linked to original sources

PubMed1993

The pedicled venous flap. An experimental study.

Musculocutaneous pedicled venous flaps on the dorsum of rats survived at a statistically significantly higher rate than musculocutaneous composite grafts (p < 0.01). With a Silastic sheet (Dow Corning) beneath, both composite grafts and pedicled venous flaps necrosed. When a Silastic sheet with holes in it to allow some revascularisation from the bed was placed beneath, the survival rate was significantly better than with a complete Silastic sheet (p < 0.01). These results demonstrate that pedicled venous flap survival depends both on the draining vein, and revascularisation from the underlying bed.

Animals↗

PubMed1993

Non-radioactive coloured microsphere measurement of regional tissue blood flow for axial pattern flaps in rabbits.

We administered non-radioactive coloured microspheres (NRACM) to measure the regional tissue blood flow (RTBF) of eight axial pattern flaps and four kidneys in four rabbits using four repeated injections into each animal. As a control, we used radioactive microspheres (RAM) for six kidneys in three rabbits. There were no significant differences for RTBF values between NRACM and RAM, between the numbers of microspheres used (2 x 10(6) and 4 x 10(6)), or between the number of injections. These results showed that NRACM is a useful and safe laboratory method.

Animals↗

PubMed1993

Blood flow through prefabricated flaps--an experimental study in rabbits.

Prefabricated flaps were created by femoral vessel implantation beneath the abdominal skin in rabbits. The area of survival and blood flow through the prefabricated flap were measured after 1, 2, 4, 6, 8, and 12-week intervals. The parameters at 6, 8 and 12-week intervals were significantly larger than those for random pattern flaps (p < 0.01), but were significantly smaller than those for axial pattern flaps (p < 0.01). The minimum interval at which the prefabricated flap could be transferred successfully was between 6 and 8 weeks in this model. Microangiography demonstrated that neovascularisation began at the distal end of the implanted vascular bundle and spread throughout the flap by 8 weeks.

Abdominal Muscles↗

PubMed1993

Vascularized tail bone grafts in rats.

A new experimental model for vascularized corticocancellous bone grafts was established by investigation of vascular anatomy of the tail in 15 adult Fischer 344 rats and determination of the viability of vascularized tail bone grafts into the abdominal wall in 22 7-week-old rats. The tail bones of 40 rats were then raised on the pedicle of the caudal artery and its venae comitantes, transferred to a resected portion in the femur, and observed for 16 weeks. The vascularized graft showed marked reactive periosteal bone formation during the first and second weeks following transfer, and thereafter, the graft continued to show active bone formation. In transverse section, the sharp processes became rounded. In the cancellous bone, both bone resorption and bone formation were noticeably activated early after transfer, although resorption predominated and the amount of the cancellous bone consequently diminished. The nonvascularized grafts showed "creeping substitution." The results suggest that morphologic adaptation occurs if living (i.e., vascularized) tail bones are transferred to long-bone femurs.

Abdominal Muscles↗

PubMed1993

Immunohistochemical analysis of cathepsin B expression in human lung adenocarcinoma: the role in cancer progression.

Production of cathepsin B by tumor cells has been linked to metastatic potential in several experimental models. Sections of 95 primary lung adenocarcinomas were examined for expression of cathepsin B using a standard avidin-biotin immunohistochemical technique. Staining for cathepsin B was observed in 22.1% of all cases and 28.0% of those of the Clara cell type. In Clara cell adenocarcinomas, cathepsin B expression correlated with positive lymph node status, presence of distant metastases, and poor prognosis (P < 0.05). However, no correlation with clinical outcome was observed in other cell types. Our data suggest that cathepsin B may be involved in invasion and metastasis in Clara cell lung adenocarcinoma.

Adenocarcinoma↗

PubMed1993

Coexisting undifferentiated thymic carcinoma and thymic carcinoid tumor.

Thymic carcinoma is an unusual neoplasm, and the undifferentiated type is rare. Thymic carcinoid is also rare. This report describes a patient with coexisting undifferentiated thymic carcinoma and a carcinoid tumor. Both lesions were completely excised. The carcinoid cells showed argyrophilic granules by Grimelius' method and immunoreactivity against neuron-specific enolase, whereas the undifferentiated carcinoma cells were negative for argyrophilic stain and immunostaining against neuron-specific enolase.

Carcinoid Tumor↗

PubMed1993

Positive end-expiratory pressure ventilation decreases plasma atrial and brain natriuretic peptide levels in humans.

To investigate the possible role of atrial and brain natriuretic peptides (ANP and BNP) in the renal effects of mechanical ventilation with positive end-expiratory pressure (PEEP), we measured changes in plasma ANP and BNP levels during PEEP in patients undergoing subtotal esophagectomy. Application of 15 cm of H2O PEEP for 1 h decreased the levels of plasma ANP and BNP from 24.4 +/- 5.5 (mean +/- SEM) and 19.0 +/- 3.5 fmol/mL to 14.4 +/- 2.1 and 15.3 +/- 3.0 fmol/mL, respectively (P < 0.05). The level of plasma cyclic guanosine monophosphate, an intracellular second messenger of ANP and BNP, also decreased from 8.4 +/- 1.5 to 5.7 +/- 0.8 pmol/mL (P < 0.05). PEEP increased the levels of plasma arginine vasopressin from 2.0 +/- 0.5 to 4.2 +/- 1.2 pg/mL, aldosterone from 36.1 +/- 4.9 to 65.3 +/- 12.7 pg/mL, and plasma renin activity from 1.4 +/- 0.5 to 2.7 +/- 0.7 ng.mL-1.h-1. During PEEP ventilation, urine output, urinary sodium and potassium excretion, osmolar clearance, and cardiac index all decreased. PEEP increased free water clearance, right atrial pressure, pulmonary arterial pressure, and pulmonary capillary wedge pressure. The level of plasma endothelin, mean blood pressure, and heart rate did not change significantly. These results suggest that not only hemodynamics and the vasopressin and renin-angiotensin-aldosterone system, but also the natriuretic peptide system (ANP and BNP), are involved in the renal effects of PEEP.

Adult↗

PubMed1993

Vascularised fibular grafts for reconstruction of the femur.

From 1979 to 1990 we treated 20 patients with large bone defects or established nonunion of the femur by vascularised fibular grafts. There were 18 men and two women with an average age at operation of 36.6 years (16 to 69). Ten patients had infected nonunion, three had post-traumatic nonunion or a bone defect without infection, four had a defect after tumour resection, and three had other lesions. The mean length of the fibular grafts was 18.1 cm. Postoperative circulatory disturbances needed revision surgery in five patients, including three with circulatory problems in the monitoring flap, but not at their anastomoses. The outcome was successful in 19 of the 20 patients with bone union at means of 6.1 months at the proximal site and 6.6 months at the distal site. Three patients had fractures of the fibular grafts but all these united in two to three months after cast immobilisation.

Adolescent↗

PubMed1993

[Establishment of a cisplatin-resistant human ovarian cancer cell line].

A human ovarian cancer cell line designated "MH" was established from ascites of a patient with ovarian serous cystadenocarcinoma treated with cisplatin. This cell line was grown for more than 2 years and over 100 passages in medium RPMI1640 containing 10% FCS. The cell doubling time, saturation density and plating efficiency was approximately 6.3 days, 5.5 x 10(4)/cm2, and 42%, respectively. Chromosomal analysis revealed aneuploidy with a modal number of 72 and 14-19 types of marker chromosomes. CA125 was detected in both the original tumor and the cultured cells. This cell line is cisplatin-resistant (IC50: 3.28 microM) and has high protein kinase C activity.

Adult↗

PubMed1993

Vascularized fibular grafts in the treatment of osteomyelitis and infected nonunion.

From 1976 to 1989, 33 patients with osteomyelitis and infected nonunion of lower extremity bones were treated with vascularized fibular grafts. There were 30 males and three females, and the ages at operation ranged from 17 to 69 years. There were 24 tibial lesions and nine femoral lesions. The fibular graft was performed immediately after lesional debridement in eight patients, but in 25 it was done secondarily after debridement and successful subsidence of inflammation. The mean interval between the last debridement and fibular grafting was ten weeks. Thirty of 33 grafts survived. The mean periods required to obtain radiographic bone union was 6.2 months at the proximal site and 6.3 months at the distal site. Local recurrence of infection occurred in four patients; all but one healed well with saucerization. Vascularized fibular graft is an effective procedure for the treatment of destructive osteomyelitis and infected nonunion.

Adolescent↗

PubMed1993

[99mTc-HMPAO SPECT in the brain death--a case report].

Brain single photon emission computed tomography (SPECT) with 99mTc-d,l-hexamethyl-propyleneamine oxime (HMPAO) was performed twice in a 78-year-old man clinically diagnosed as brain death according to the standard criteria of the Japanese Ministry of Welfare. The first brain SPECT demonstrated the tracer accumulation in the brain, indicating preserved cerebral blood flow. The second brain SPECT performed 3 days later revealed cessation of the blood flow. In patients with preserved cerebral blood flow, the diagnosis of brain death cannot be made, even if they meet the existing criteria, because previous report noted the recovery in some of those patients. Brain perfusion SPECT plays an important role as a confirmatory test for the diagnosis of the brain death.

Aged↗

PubMed1993

[A case report of an advanced esophageal carcinoma treated by neoadjuvant chemotherapy (CDDP + 5-FU) and evaluation of effect on metastatic lymph nodes].

A 69-year-old woman was diagnosed to have type 2 advanced esophageal carcinoma measuring Im 9 cm by X-ray and endoscopic examination. CT scan revealed much swelling of No. 106 and 9 lymph nodes. As the patient had dry cough and these lymph nodes, we tried neoadjuvant chemotherapy for reduction of metastatic lymph nodes. The regimen consisted of CDDP 80 mg/m2 (day 1), 5-FU 800 mg/m2 (day 1-4, continuous). After 2 courses, an operation was performed. Histopathological examination of the section of the primary tumor revealed that only a few cancer cells nests (sq. c.c., mod.) remained in the muscle layer. In 41 dissected lymph nodes, 12 lymph nodes had metastatic cancer cell nests before neoadjuvant chemotherapy and only 4 lymph nodes had a few remaining cancer cells nests. The effect of CDDP + 5-FU therapy is the same for primary tumor and lymph nodes.

Aged↗

PubMed1993

Revascularization procedures in the treatment of Kienböck's disease.

Lunate revascularization by means of vascular bundle implantation is one of the useful procedures for stages I and II Kienböck's disease, but for stage III, it should be combined with some biomechanical procedure or partial carpal fusion. There is no indication for this procedure in stage IV disease.

Adolescent↗

PubMed1993

Extracorporeal circulation for tissue transplantation (in the case of venous flaps).

During free-tissue transplantation, recipient vessels are often crushed as a result of trauma or radiation therapy, making anastomosis of vessels difficult. In some cases, a second operation is unavoidable because of formation of a postoperative thrombus at sites of the anastomosis. To solve such problems, it should be possible to transplant tissue anywhere in the body without vascular anastomosis by extracorporeal circulation. This study mainly concerned venous flaps that were spindle-shaped and 4 x 3 cm in size. One hundred and forty-six male Japanese White rabbits, weighing 2.0 to 2.5 kg, were used. Stabilized hemoglobin, lactated Ringer's solution, whole blood, and plasma were used as perfusate. Each of these perfusates was injected at a rate of 5 ml per hour continuously for 3 days in good recipient sites and for 7 days in poor recipient sites. Five rabbits were used in each group. The flaps were examined histologically and electron microscopically. Moreover, in the plasma group, microangiography was performed to observe blood circulation between the flap and the surrounding tissue. The flaps survived in all cases in which the plasma group had good recipient beds but did not survive in any of the other cases, in which degeneration of the endothelial cells was detected prior to edema. According to the results of this examination, tissue viability of the venous flap could be maintained for at least 3 days by perfusion of plasma. During this time, in the cases of good recipient sites, blood may begin to recirculate between the flap and the surrounding tissue.

Angiography↗

PubMed1993

[A case of chest wall abscess due to Salmonella newport].

A 18-year-old female with a history of precordial pain was admitted. There was a mass (3.5 x 2.5 cm) in the right inframammary region which was suspected to be chest wall tumor on the basis of CT scan and Ga scintigraphy findings. Exploratory surgery, consisting of total resection of the tumor without removing the ribs, was performed and revealed an abscess. Culture of pus from the abscess grew Salmonella newport (0 antigen 8, H antigen eh; 1.2). Focal infection with Salmonellosis is discussed. Surgical treatment is necessary in addition to chemotherapy.

Abscess↗

PubMed1992

Bone formation process in porous calcium carbonate and hydroxyapatite.

This study determined the bone formation in porous calcium carbonate (CC) and porous hydroxyapatite (HA) in ectopic sites. The bone formation stimulus was derived from bone marrow cells. CC and HA in the shape of disks were implanted with or without rat marrow cells into subcutaneous sites of syngeneic rats. The CC and HA had identical microstructure: pore size was 190-230 microns, porosity was 50-60% and they were fully interconnected. Bone did not form in any implants without marrow cells (disks themselves), whereas bone consistently formed in the pores of all implants with marrow cells after 4 weeks. The bone formation of both CC and HA occurred initially on surface of the pore regions and progressed toward the center of the pore. Scanning electron microscopy and electron-probe microanalysis revealed a continuum of calcium at the interfaces of both bone/CC and bone/HA implants. These results indicate that the bone formation in calcium carbonate derived from marine corals is comparable to the bioactive hydroxyapatite.

Animals↗

PubMed1992

Expression of the transin, c-fos, and c-jun genes in rat transplantable osteosarcomas and malignant fibrous histiocytomas.

The expression of the transin, c-fos, and c-jun genes was assessed in transplantable osteosarcomas and malignant fibrous histiocytomas, as well as in pancreatic duct adenocarcinomas and hepatocellular carcinomas of rats and hamsters. Northern blot analysis revealed that both an undifferentiated osteosarcoma of spontaneous origin (SOS) and 4-hydroxyaminoquinoline 1-oxide (4-HAQO)-induced malignant fibrous histiocytomas with metastatic potential to the lung showed remarkably increased expression of transin mRNA transcripts. This was not the case for the other tumors. Interestingly, levels of transin mRNA were lower in lung metastatic lesions than in primary subcutaneous SOS tumors. The primary SOS and MFH expressed both c-fos and c-jun genes in conjunction with the transin gene, whereas the non-transin expressers, a 4-HAQO-induced osteosarcoma (COS) and the pancreatic duct adenocarcinomas, demonstrated one or the other, but not both. These results suggest a possible involvement of transin expression in the progression of spontaneous osteosarcomas and 4-HAQO-induced malignant fibrous histiocytomas in rats. Expression of the c-fos and c-jun genes may play a regulatory role in this process.

4-Hydroxyaminoquinoline-1-oxide↗

PubMed1992

Continuous local intraarterial infusion after prolonged arterial stasis in the fingers and toes.

Seven patients with trauma to eight digits and one toe went untreated for arterial stasis, with subsequent development of posttraumatic changes in skin coloration. In two patients involving two digits, a daily dose of 2,000 ml containing 240,000 U urokinase, 80 micrograms prostaglandin E1, and 10,000 U heparin in lactated Ringer's solution was administered by intravenous infusion for 10 consecutive days; one of the two digits became necrotic. In all subsequent patients, a daily dose of 80 ml containing 240,000 U urokinase, 40 micrograms prostaglandin E1, 10,000 U (maximum) heparin, and low-molecular-weight dextran was administered by continuous local intraarterial infusion for 10 consecutive days. These seven extremities survived, even in the case of two digits and one toe with over 50 hr of arterial stasis. We believe that revascularization of extremities following prolonged periods of arterial stasis may be possible by means of continuous local intraarterial infusion of antithrombotic agents.

Aged↗