Biomedical subjects

S Kanazawa

Publications and source records attributed to S Kanazawa.

At least 91 records · Page 5Linked to original sources

PubMed1996

p59fyn-p125FAK cooperation in development of CD4+CD8+ thymocytes.

p59fyn is an Src family nonreceptor tyrosine kinase that has been suggested to play an important role in T-cell development and function. p125FAK is a unique nonreceptor tyrosine kinase and has been known to respond to integrin-extracellular matrix interactions. To examine their roles in thymocytes, heterozygous fak mutation was introduced into homozygous Fyn deficiency. The double mutation, but neither Fyn deficiency nor FAK heterozygosity alone, displayed impaired development of CD4+CD8+ thymocytes with atrophy of the thymic cortex, suggesting a unique cooperation between p59fyn and p125FAK in CD4+CD8+ T-cell development.

Animals↗

PubMed1996

Non-penetrating traumatic tricuspid regurgitation after mitral valve replacement.

A case of traumatic rupture of the tricuspid chordae tendineae with severe regurgitation in a patient who previously had mitral valve replacement is presented. In this case, it is strongly suggested that a firm pericardial adhesion of the anterior right ventricular wall became a factor of the disruption of the tricuspid valve under a slight precordial blow.

Adult↗

PubMed1996

In vitro and in vivo testing of an implantable motor-driven left ventricular assist device.

A totally implantable motor-driven left ventricular assist device (LVAD) has been developed and tested. The performance of this LVAD was tested in a mock circulatory system. This pump provided 8 L/min of output against a mean afterload of 120 mm Hg with a filling pressure of 20 mm Hg when the pump was operated in the fill/empty mode. The right and left pumps were tested in a mock loop. The right pump afterload was kept in the range from 23-32 mm Hg. With increase in the left pump afterload, the pump power output varied from 1.64 to 2.37 W. The instantaneous motor power input varied from 22.6 to 30.6 W with the total system efficiency ranging from 6.7 to 9.4%. To date, 4 in vivo studies have been conducted for up to 12 h. Two animals survived 12 and 10 h, respectively. Termination was due to bleeding in 1 animal, vent tube obstruction in 1, and respiratory failure in 2. All animals died of technical failure. Another experiment is to be undertaken, and a newly designed cannula is now being manufactured.

Abdominal Muscles↗

PubMed1996

Cloning and sequence analysis of czc genes in Alcaligenes sp. strain CT14.

We have isolated 14 cadmium (Cd)-resistant, soil-borne bacteria. Among those, strain CT14, which was identified as an Alcaligenes sp., has a czc (cadmium, zinc, and cobalt divalent cation resistant determinant) system. Here we report the nucleotide sequence of 4 genes (czcCBAD) of the system. CzcCBA showed over 98% identity with those of A. eutrophus CH34, however, CzcD, the distal gene product, was 117 amino acids longer than that (199 amino acids) of A. eutrophus CH34, and had considerable similarity to the members of the CDF (cation diffusion facilitator) family proteins all over the region.

Alcaligenes↗

PubMed1996

[A case of tricuspid and mitral valve replacement for incomplete endocardial cushion defect].

A 56-year-old female who was diagnosed incomplete endocardial cushion defect, underwent closure of ostium primum defect and repair of mitral cleft 2 years ago. Mitral and tricuspid ring annuloplasty was done 9 months after the first operation because of an increment of mitral and tricuspid valve regurgitation. The Third operation, mitral valve replacement by mechanical valve and tricuspid valve replacement by bioprosthetic valve, was performed because of the gradually increased mitral stenosis and tricuspid regurgitation. Post-operative course was uneventful. Resected anterior cusp of mitral and tricuspid valve revealed hypertrophy and shortness macroscopically, and revealed fibrosis and calcification histopathologically. It was considered that remarkable regurgitation was due to secondary change of both valves. We concluded that valve replacement should be performed for case of secondary change of atrioventricular valve in adult patient.

Endocardial Cushion Defects↗

PubMed1996

[Traumatic injuries of the thoracic aorta--report of five cases].

Five cases of traumatic aneurysm of the thoracic aorta associated with blunt chest trauma are described. Although we lost one case, four cases were successfully treated. Case 1, This was a 22-year-old female who underwent surgery for graft replacement of the descending thoracic aorta under extracorporeal circulation two days after injury. Case 2, This was a 17-year-old male who underwent surgery for graft replacement of the descending thoracic aorta under extracorporeal circulation 24 hours after injury. Case 3, This was a 56-year-old female who underwent surgery for graft replacement of the descending thoracic aorta under extracorporeal circulation 24 hours after injury. Case 4, This was a 69-year-old male who underwent surgery for graft replacement with three branches for an aortic arch aneurysm under extracorporeal circulation one month after injury. Despite an emergency operation, we lost case 5 (a 21-year-old male) because of a complete discontinuity of the aortic isthmus. The postoperative course of the other four cases was uneventful. Vessel injury may be more widespread than preoperative radiographic findings demonstrates. Blunt chest trauma is usually accompanied by multisystem injury. Therefore, it is imperative to determine the first priority of treatment based on further preoperative examination in cases having associated injuries.

Adolescent↗

PubMed1996

[A case of swallowed fish bone-induced esophageal perforation and mediastinitis treated with pedicled omental graft].

We experienced a case of 47-year-old man who suffered swallowed fish bone-induced esophageal perforation with purulent mediastinitis and underwent direct suture closure of the perforation and reinforcement with a pedicled parietal pleura four days after the onset. Postoperative esophageal suture insufficiency was occured and reoperation was performed two months after the first operation. The esophageal fistula was plugged with a pedicled omental graft successfully. The postoperative course of the patient was uneventful and he discharged 45 days after the second operation. A reinforcement by pedicled omental graft for esophageal rupture accompanied with mediastinitis was considered to be a useful procedure.

Animals↗

PubMed1996

[Percutaneous CT guided bone biopsy in patients with suspected bone neoplasm].

Bone biopsy is necessary for the diagnosis of ambiguous skeletal lesions. Although several merits of computed tomography (CT)-guided percutaneous needle biopsy have been documented, few radiologists have performed this procedure in Japan. We performed this procedure with a newly introduced bone biopsy needle (OSTYCUT, angiomed, Karlsruhe, Germany) under CT guidance and evaluated the results. CT-guided bone biopsy (pelvic[n = 11]vertebral[n = 10], femoral[n = 1], sternal[n = 1]) was performed in 19 consecutive patients. Seventeen patients were suspected metastatic disease, and the others were suspected primary bone tumor. All biopsies but one were diagnostic. Malignancy was proved in 11 lesions. Three patients with prostatic carcinoma were proved to show no malignancy of bone lesions after a series of hormonal and chemotherapies. In one patient with both malignant mesothelioma and cervical carcinoma, the biopsy specimen from thoracic vertebra proved metastasis from mesothelioma. CT-guided bone biopsy is useful to evaluate the presence of malignancy and the effect of therapy for it, and to determine the primary site.

Adult↗

PubMed1995

Mesodermal defect in late phase of gastrulation by a targeted mutation of focal adhesion kinase, FAK.

FAK is a unique non-receptor protein tyrosine kinase that was found in cellular focal adhesions. An increasing number of in vitro observations has suggested that FAK mediates signaling through integrins brought about by interactions with extracellular matrix (ECM). It is highly tyrosine-phosphorylated in v-src-transformed cells and during embryogenesis. To clarify the function of FAK in cell-ECM interactions, embryonic phenotype of its mutant was analysed. FAK-deficient embryos could implant and initiate gastrulation normally, but showed abnormalities in subsequent development. The abnormalities were characterized as a general deficiency in mesoderm, and the phenotype was quite similar to that caused by fibronectin-deficiency. The results suggest that FAK mediates fibronectin-integrin interactions uniquely at this stage of development, thereby playing an essential role in development of mesodermal cell lineages.

Animals↗

PubMed1995

Integrin stimulation decreases tyrosine phosphorylation and activity of focal adhesion kinase in thymocytes.

FAK, focal adhesion kinase, is expressed in a variety of cell types and has been suggested to transduce signals brought about by integrin-extracellular matrix (ECM) interactions. Integrin stimulation increases tyrosine phosphorylation and activity of FAK in all the cells examined to date. In contrast, in thymocytes stimulation of VLA-4 (alpha 4 beta 1) and LFA-1 (alpha L beta 2) resulted in a marked decrease in tyrosine phosphorylation and activity of FAK.

Animals↗

PubMed1995

Reduced cell motility and enhanced focal adhesion contact formation in cells from FAK-deficient mice.

The intracellular protein tyrosine kinase FAK (focal adhesion kinase) was originally identified gy its high level of tyrosine phosphorylation in v-src-transformed cells. FAK is also highly phosphorylated during early development. In cultured cells it is localized to focal adhesion contacts and becomes phosphorylated and activated in response to integrin-mediated binding of cells to the extracellular matrix, suggesting an important role in cell adhesion and/or migration. We have generated FAK-deficient mice by gene targeting to examine the role of FAK during development. Mutant embryos displayed a general defect of mesoderm development, and cells from these embryos had reduced mobility in vitro. Surprisingly, the number of focal adhesions was increased in FAK-deficient cells, suggesting that FAK may be involved in the turnover of focal adhesion contacts during cell migration.

Animals↗

PubMed1995

Judgment of gender through facial parts.

Japanese male and female undergraduate students judged the gender of a variety of facial images. These images were combinations of the following facial parts: eyebrows, eyes, nose, mouth, and the face outline (cheek and chin). These parts were extracted from averaged facial images of Japanese males and females aged 18 and 19 years by means of the Facial Image Processing System. The results suggested that, in identifying gender, subjects performed identification on the basis of the eyebrows and the face outline, and both males and females were more likely to identify the faces as those of their own gender. The results are discussed in relation to previous studies, with particular attention paid to the matter of race differences.

Adolescent↗

PubMed1995

Hepatic arteriography in patients with hepatocellular carcinoma: change in findings caused by balloon occlusion of tumor-draining hepatic veins.

OBJECTIVE: A previous study suggested that temporary occlusion of a segment of the hepatic vein causes an increase in arterial flow and retrograde portal flow in the occluded segment. Such occlusions might improve the efficacy of arterial infusion therapy. Accordingly, we studied the change in blood flow visible on hepatic arteriograms when a segment of the hepatic vein is temporarily occluded in patients with hepatocellular carcinoma. MATERIALS AND METHODS: The study group consisted of 24 patients with nodular-type hepatocellular carcinoma. Conventional hepatic arteriography was followed by hepatic arteriography performed using a balloon catheter to occlude the hepatic vein that was most closely associated with the tumor. Visualization of the tumor-draining veins, portal vein branches, the degree of tumor vascularity, and the density of the hepatogram on the hepatic arteriogram were retrospectively compared before and during venous occlusion. The veins were evaluated visually; an increase of tumor vascularity was defined as an increase in the number of countable tumor vessels during occlusion, and a dense hepatogram was considered to be a definite sinusoidgram induced by venous occlusion. RESULTS: Conventional hepatic arteriography showed the tumor-draining veins to be branches of the portal vein in only two of the 24 patients (8%). Hepatic arteriography during venous occlusion, however, showed the tumor-draining veins to be branches of the portal vein in four of the patients (17%). An increase in the degree of tumor vascularity with venous occlusion was observed only in a patient with an initial arteriohepatic vein shunt. Dense hepatogram and hepatofugal opacification of the portal vein branches in the occluded, tumor-bearing segment were obtained in 10 patients (42%). Eight of these did not have liver cirrhosis, whereas all of the remaining 14 patients did (p < .001). CONCLUSION: Our results suggest that occlusion of a segment of the hepatic vein may be useful during arterial infusion of hepatocellular carcinoma.

Adult↗

PubMed1995

[A case of thymic squamous cell carcinoma successfully treated with curative resection].

A case of rare thymic squamous cell carcinoma was reported. A 46-year-old female was admitted to our hospital because of an abnormal shadow on chest X-ray. Chest CT showed anterior mediastinal tumor and histological diagnosis of squamous cell carcinoma was made by needle biopsy under CT guide. Esophagus and lung were no abnormal findings, we thought the primary region was thymus. On mid-sternotomy, anterior mediastinal tumor was resected with thymus, right phrenic nerve and pericardium, however it was not direct invasion to heart, great vessels, lung and chest wall. Resection of peripheral fatty tissue and dissection of mediastinal lymph nodes as much as possible, it was not capsular invasion and mediastinal lymph nodes metastasis and complete curative resection was able to perform. Additional radiation therapy was done, post-operative course was uneventful.

Carcinoma, Squamous Cell↗

PubMed1994

Selective repression of growth-regulating cdk2, cyclin E and E2F1 genes in human cell senescence.

Normal human diploid TIG-1 fibroblasts underwent replicative senescence around 64-68 population doubling levels (PDL) by the irreversible serum-unresponsive G1-growth arrest. Repression of growth-promoting genes was searched in this study. The RT-PCR and Western blot analyses have shown that in senescent TIG-1 cells at PDL64-67, cdk2 and cyclin E were selectively repressed at the mRNA and protein levels even after serum stimulation, and cdc2 and cyclin A were less repressed than cdk2 and cyclin E. Such a specific lack of cdk2 and cyclin E proteins correlated with unphosphorylation of the retinoblastoma gene product (pRB) in senescent cells. Transcription factor E2F1 was also completely repressed at the mRNA and protein levels in senescent TIG-1 cells. Middle-passage cells exhibited active expressions of all the above genes and pRB phosphorylation. Therefore, the present results have indicated the selective repressions of cdk2, cyclin E and E2F1 in senescent cells.

Base Sequence↗

PubMed1994

The relation between cubital tunnel syndrome and the elbow alignment.

The authors reviewed forty-three surgically managed cases of cubital tunnel syndrome treated during the past twelve years. Surgery had been performed on thirty-one men and twelve women. Their average age was 46.8 years old. The etiology of cubital tunnel syndrome had been determined as follows: There were twenty-three cases of osteoarthritis of the elbow joint. There were four cases of isolated cubitus valgus deformity. There were three cases of isolated cubitus varus deformity. There were three cases of rheumatoid arthritis. One patient had sustained trauma to the cubital tunnel. In nine other patients there were various causes but no joint malalignment. The selection of the surgical technique for the correction of cubital tunnel syndrome was a function of the etiology of the condition. Cubital tunnel syndrome from osteoarthritis was surgically managed with a modified King technique. Ulnar neuropathy with a cubitus valgus deformity was managed with an ulnar nerve anterior transposition. Ulnar neuropathy with a cubitus varus deformity was managed with a neurolysis. The surgical outcome for cubital tunnel syndrome in patients with an angular deformity at the elbow frequently was not optimum. However, although some patients remained symptomatic, the majority of postoperative patients did obtain improved motor strength and conduction velocities. This confirmed the efficacy of surgical management regardless of the cubital tunnel syndrome etiology.

Adolescent↗

PubMed1994

A theory of the value of children.

This paper uses a non-standard value assumption--uncertainty reduction--to explain parenthood. We begin by reviewing the inadequacies of normative and standard rational choice explanations of shifts in fertility behavior. Then we propose a theory of the value of children based on the uncertainty-reduction assumption. Next we generate a range of hypotheses that follow both from this assumption and from a subsidiary assumption of marital solidarity enhancement. Finally, we explore the extent to which implications based on these new ideas are supported by the relevant empirical literature.

Adolescent↗

PubMed1993

[Percutaneous transhepatic gastrostomy with CT guidance in patients with partial gastrectomy].

Percutaneous transhepatic gastrostomy was performed in two patients, one with partial gastrectomy and Billroth I anastomosis and one with esophageal reconstruction with subtotal stomach, in whom oral feeding was precluded. In both patients, percutaneous gastrostomy with fluoroscopic guidance was impossible since the gastric remnants were small, had a high subcostal position, and were overlain by the transverse colon, lung and left lobe of the liver. The only route available to avoid the overlying bowel and lung was the transhepatic approach. The gastric remnants were punctured with a 22-gauge PTC needle through the left lobe of the liver with CT guidance, and an 8 Fr. Cope-type catheter was fluoroscopically placed in the gastric remnant or the duodenum after tract dilatation over the guide wire. No complications occurred during or after the procedures, and the condition of both patients was greatly improved. Although gastrostomy in patients with partial gastrectomy is thought to be very difficult, percutaneous transhepatic gastrostomy with CT guidance is easy and may be safe since adhesion between the liver and gastric remnant can prevent massive hemorrhage or displacement of the catheters.

Aged↗