Search PubMed⌕ Search

Biomedical subjects

S Oki

Publications and source records attributed to S Oki.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Efficacy of adjuvant hepatic arterial infusion chemotherapy following resection of colorectal liver metastases].

PURPOSE: The aim of this study is to evaluate the effect of adjuvant hepatic arterial infusion chemotherapy (HAIC) following liver resection on the frequency of residual liver recurrence and overall survival. PATIENTS AND METHODS: During 1992 to 1997, 84 patients with liver metastasis from colorectal cancer resected curatively had undergone adjuvant HAIC. The regimen of the HAIC is 1,500 mg of 5-FU by 24-hr continuous infusion once a week for eight weeks. 37 cases in the HAIC group, including patients given more than 7 g of 5-FU, were compared with the control group. RESULT: The cumulative 5-year liver recurrence-free ratios were 72.6% in the HAIC group and 29.8% in the control group (p = 0.0005). The cumulative 5-year survival ratios were 61.4% in the HAIC group and 28.0% in the control group (p = 0.0069). Multivariate analysis revealed that more than 5 mm of surgical margin and adjuvant HAIC significantly decreased the risk of recurrences in residual liver. CONCLUSION: Adjuvant HAIC is an effective procedure to prevent recurrence in residual liver and improve the prognosis of patients with liver metastasis from colorectal cancer.

Adult↗
PubMed1999

[Supratentorial ectopic ependymoma: a case report].

Ependymomas usually arise from the ventricular surface and approximately two-thirds of them are infratentorial. We present an unusual case of supratentorial ependymoma located in the parietal parenchyma and exhibiting no continuity with the ventricular system. On March 30, 1998, a 63-year-old woman was admitted to our neurosurgical service because of a sudden consciousness loss attack two weeks before. On admission, neurological examination revealed no abnormal findings. Computerized tomography (CT) revealed a mass lesion of the parietal lobe which was enhanced homogeneously. Magnetic resonance imaging (MRI) also showed the mass of the parietal lobe which was iso-intense on T1-weighted images, iso and high intense on T2-weighted images and homogeneously enhanced by administration of Gd-DTPA. In the angiography, left carotid angiograms showed a tumor stain. On February 26, 1998, total removal of the tumor was performed using stereotactic craniotomy with neuronavigator and intraoperative echography. After surgery, focal radiation therapy (56Gy) was carried out. The pathological diagnosis was cellular ependymoma with partial clear cell components. Several kinds of tumor may occur in the cerebral parenchyma. We conclude, however, that ependymoma has to be included in the differential diagnosis when the tumor location is distant from the ventricles.

Brain Neoplasms↗
PubMed1998

Micrometastatic colorectal cancer lesions in the liver.

A surgical resection of metastatic liver lesions from colorectal cancer contributes to an improved prognosis. However, the postoperative recurrence rate remains high, particularly in the residual liver. This is probably the result of the failure to detect small lesions. In the present study, we histologically examined the presence of intrahepatic micrometastases, which are considered to be related to recurrence in the residual liver. Intrahepatic micrometastases were histologically examined in 31 resected specimens of 25 patients undergoing a hepatic resection because of metastasis to the liver from colorectal cancer. Micrometastases were found in 14 of 25 cases (56.0%). They were located in the portal veins, central veins, sinusoid, and bile ducts. The longest distance from the main metastasis was 38.2 (mean 7.5 +/- 8.0) mm. The size of the macrometastases became larger, and the frequency of micrometastases and the distance of micrometastases from macrometastases had a tendency to increase. Continuous invasion of the macrometastases into the micrometastases through the vasculature or bile duct was also observed. These results suggested that some micrometastases observed in the metastatic liver from colorectal cancer were thus seeded from the primary lesions, while other micrometastases originated from the macrometastatic lesions as satellite lesions.

Colorectal Neoplasms↗
PubMed1998

Identification of a novel splicing mutation and 1-bp deletion in the 17alpha-hydroxylase gene of Japanese patients with 17alpha-hydroxylase deficiency.

We report studies of two unrelated Japanese patients with 17alpha-hydroxylase deficiency caused by mutations of the 17alpha-hydroxylase (CYP17) gene. We amplified all eight exons of the CYP17 gene, including the exon-intron boundaries, by the polymerase chain reaction and determined their nucleotide sequences. Patient 1 had novel, compound heterozygous mutations of the CYP17 gene. One mutant allele had a guanine to thymine transversion at position +5 in the splice donor site of intron 2. This splice-site mutation caused exon 2 skipping, as shown by in vitro minigene expression analysis of an allelic construct, resulting in a frameshift and introducing a premature stop codon (TAG) 60 bp downstream from the exon 1-3 boundary. The other allele had a missense mutation of His (CAC) to Leu (CTC) at codon 373 in exon 6. These two mutations abolished the 17alpha-hydroxylase and 17,20-lyase activities. Restriction fragment length polymorphism (RFLP) analysis with a mismatch oligonucleotide showed that the patient's mother and brother carried the splice-site mutation, but not the missense mutation. Patient 2 was homozygous for a novel 1-bp deletion (cytosine) at codon 131 in exon 2. This 1-bp deletion produces a frameshift in translation and introduces a premature stop codon (TAG) proximal to the highly conserved heme iron-binding cysteine at codon 442 in microsomal cytochrome P450 steroid 17alpha-hydroxylase (P450c17). RFLP analysis showed that the mother was heterozygous for the mutation.

Adolescent↗
PubMed1998

Capillaries with fenestrations around regenerating muscle fibers in the soleus muscle of the dystrophic (dy) mouse.

To investigate the morphological changes in capillaries around regenerating muscle fibers in the dystrophic (dy) mouse, we examined capillaries in the soleus muscles of 30-day-old control and dy mice by electron microscopy. In the control mice, the intramuscular capillaries were continuous. In the dystrophic mice, the muscles contained degenerative muscle fibers and many small muscle fibers regenerating after necrosis; these fibers had centrally located nuclei. The capillaries in the dy mice were mostly continuous, but some had a narrow vascular lumen around regenerating muscle fibers, possibly indicating newly formed capillaries. Moreover, about 20% of the capillaries with a narrow vascular lumen had a small number (less than five) of fenestrae bridged by a single-layered diaphragm. These findings suggest that capillary networks around muscle fibers regenerating after necrosis are remodeled by newly formed capillaries, and some of these capillaries have fenestrae in the endothelium to increase the supply of nutrients and oxygen to the regenerating muscle fibers.

Animals↗
PubMed1998

Three-dimensional structure of the vascular network in normal and immobilized muscles of the rat.

OBJECTIVE: To examine whether there are three-dimensional changes in capillaries of rat soleus muscle during mechanical limb immobilization. DESIGN: Scanning electron microscopy, with the microcorrosion cast technique, was used to examine vascular networks in immobilized Wistar rat soleus muscles from 4 to 12 weeks after limb immobilization and to compare these networks with those in the control muscle. INTERVENTION: Immobilization of the soleus muscle was achieved by unilateral pinning of the ankle joint in full plantar flexion. RESULTS: The wavelike structure of the vascular network in the control muscles changed into a straight configuration in 8- and 12-week immobilized muscles.

Animals↗
PubMed1998

Morphodifferentiation of skeletal muscle fiber ends at the myotendinous junction in the postnatal Chinese hamster: a scanning electron microscopic study.

The postnatal morphodifferentiation of muscle fiber ends at the myotendinous junction was examined by scanning electron microscopy in gastrocnemius muscles of the Chinese hamster. Muscle fiber ends during the first week were simply conical or slightly complex, having a few pit-like invaginations and longitudinal and narrow clefts. By the second week, fiber ends gradually became complicated with an increased number of clefts and finger-like processes. Pits and short clefts linearly arranged towards the fiber tip were visible until the second week. This possibly indicates the linear elongation of the clefts by the fusion of adjacent pits to one another and to preexisting clefts. By the fourth week, the fiber ends had almost fully matured and displayed numerous cytoplasmic processes and lateral grooves.

Animals↗
PubMed1998

[Basic and clinical studies on tazobactam/piperacillin in pediatric field].

A drug susceptibility test of the combination drug TAZ/PIPC, which consists of a newly developed beta-lactamase inhibitor, tazobactam (TAZ), and one of penicillin antibiotics, piperacillin (PIPC), with combination ratio of 1:4 in potency, was conducted with stock strains and clinical isolates. The clinical efficacy and safety of its injection was also evaluated in children with a variety of infectious diseases. The results were as follows: 1. In susceptibility test, 114 strains from 4 species of stock strains were treated with 8 drugs, that is, TAZ/PIPC, PIPC, penicillin G (PCG), ampicillin (ABPC), cefotiam (CTM), cefotaxime (CTX), ceftazidime (CAZ), and sulbactam/cefoperazone (SBT/CPZ). Of three clinically isolated species from patients, Staphylococcus aureus (S. aureus) was treated with TAZ/PIPC, PIPC, methicillin (DMPPC), CTM, CTX, and SBT/CPZ, and the others were treated with the same drugs except for DMPPC. The MICs were measured for these bacterial strains inoculated at the concentration of 10(6) CFU/ml. The MIC90 values of TAZ/PIPC against 45 strains of Streptococcus pyogenes (S. pyogenes), one of the stock cultures of Gram-positive cocci, were 0.05 microgram/ml and similar to those of PIPC, CTM, CAZ, and SBT/CPZ. The MICs of TAZ/PIPC for 28 strains of Streptococcus agalactiae (S. agalactiae) were 0.39 microgram/ml and similar to those of PIPC, CTM, CAZ, and SBT/CPZ. As for Gram-negative bacilli, the MIC90 of TAZ/PIPC against 10 strains of Bordetella pertussis (B. pertussis) were 0.10 microgram/ml and similar to those of PIPC. The MIC90 of TAZ/PIPC against 31 strains of Haemophilus influenzae (H. influenzae) were 0.05 microgram/ml and similar to those of PIPC, CTX, and SBT/CPZ. Regarding Gram-positive cocci isolated from patients received this combination drug, the MIC90 of TAZ/PIPC against 2 strains of S. aureus, a non beta-lactamase producing strain and a low-beta-lactamase producing strain, were 0.78 microgram/ml and 3.1 micrograms/ml, respectively; the former value was similar to those of PIPC, DMPPC, CTM, and CTX, and the latter was similar to those of PIPC, DMPPC, CTX, and SBT/CPZ. Of 4 strains of Streptococcus pneumoniae, 2 strains were inhibited at 0.05 microgram/ml, and the others at 1.56 micrograms/ml; both values were similar to those of PIPC, SBT/CPZ. As for Gram-negative bacilli, 6 of 7 strains of H. influenzae did not produce beta-lactamase and 1 strain was a high producer. The MICs of TAZ/PIPC against beta-lactamase nonproducing strains were < or = 0.025 microgram/ml in 5 strains and 0.39 microgram/ml in 1 strain, and the values were similar to those of PIPC and SBT/CPZ. While the MIC of TAZ/PIPC against the high beta-lactamase producing strain was 0.78 microgram/ml; similar to that of SBT/CPZ and smaller than that of PIPC. 2. The results of clinical effects on 7 diseases in 33 cases were as follows: TAZ/PIPC was clinically judged "excellent" in 17 (51.5%); good in 14 (42.4%); fair in 2 (6.1%). No case with no response was seen in this study, and the total efficacy rate of "excellent" and "good" was 93.9%. 3. Bacteriological effects were evaluated in 17 strains of 4 species, and all of them were eradicated. 4. Adverse reactions were judged in 35, which consisted of 33 in which the clinical effects were evaluated and 2 dropped from this study. Of these cases, diarrhea was observed in 4 (11.4%). 5. Laboratory tests revealed an increase in platelets in 1 of 32 cases (3.1%), and eosinophilia in 2 of 29 cases (6.9%). Biochemical profile showed an increase in GPT alone and abnormal increases in both GOT and GPT in 1 each out of 21 cases.

Acute Disease↗
PubMed1997

Metastasis of rectal cancer to lymph nodes and tissues around the autonomic nerves spared for urinary and sexual function.

PURPOSE: To clarify the indications for autonomic nerve-sparing operations for rectal cancer, the presence of lymph nodes and metastasis in the tissue around the autonomic nerve were examined in 28 rectal cancer patients. These were staged as pT2 in 8 patients, pT3 in 19 patients, and pT4 in 1 patient histopathologically. METHODS: The specimens of the autonomic nerve including the inferior mesenteric plexus, preaortic plexus, superior hypogastric plexus, hypogastric nerve, and pelvic plexus were removed with radical abdominopelvic lymphadenectomy after the autonomic nerve-sparing rectal cancer operation. RESULTS: In the tissue around the autonomic nerve, lymph nodes were 11.2 +/- 9.6 in number and 2.6 +/- 2.4 mm in size (mean +/- standard deviation). The frequency of presence of lymph nodes was higher and the number of lymph nodes was larger in the inferior mesenteric plexus (70.4 percent; 3.6) and the preaortic plexus (66.7 percent; 2.1) than in the left and right pelvic plexuses (39.1 percent, 1; 36 percent, 1). Metastasis to the lymph nodes or lymphatic permeation in the tissue around the autonomic nerve were observed in four cases (14.3 percent) of lower rectal cancer, consisting of three with Stage III cancer (pT3, pN1-3, and M0) and one with Stage IV cancer (pT4, pN1, and pM1 (HEP)). CONCLUSION: Radical rectal excision that includes lymph nodes and adjacent tissue around the autonomic nerves may result in metastatic tumor removal that would otherwise be left in situ with nerve-sparing techniques for advanced rectal cancer in Stage III.

Autonomic Pathways↗
PubMed1997

An assessment of the anatomical relationship between the pelvic plexus and the rectal wall to determine the indications for its preservation in surgery for rectal cancer.

Preservation of the pelvic plexus in surgery for rectal cancer could shorten the distance between the cancer and the lateral resection margin, whereby the curability of the operation may be reduced. To clarify the indications for preserving the pelvic plexus in such surgery, the relationship of the pelvic plexus to the rectum and rectal cancer was investigated anatomically in 12 autopsied specimens and 12 surgical specimens. The rectum and anus were dissected with all the pelvic organs from autopsied cadavers and transverse sections were prepared at 10-mm intervals after fixation. The location of the pelvic plexus was then measured on the tissue preparations, and compared to that of surgical specimens from rectal cancers with concurrent resection of the pelvic plexus. The pelvic plexus was located from 3.3 +/- 1.2 cm above to 2.3 +/- 1.9 cm below the peritoneal reflection in the autopsied specimens. The average distances between the muscularis propria and the pelvic plexus in the autopsied specimens and surgical specimens were 8.3 +/- 3.5 mm and 14.7 +/- 4.5 mm, respectively, showing a significant difference (P < 0.05). Pelvic plexuses were located about 10 mm from the outer margin of rectal muscularis propria. These findings indicate that concurrent resection of the pelvic plexus may be required to secure sufficient surgical clearance in pT3 rectal cancers, especially those invading deeply beyond the muscularis propria (a2).

Cadaver↗
PubMed1997

Topographic comparison of subneural apparatuses at neuromuscular junctions in normal and dystrophic (mdx) mice: a scanning electron microscope study.

The differences in the morphodifferentiation of subneural apparatuses (SNAs) at neuromuscular junctions (NMJs) in the extensor digitorum longus muscle of normal and dystrophic (mdx) mice were examined by scanning electron microscopy. In normal mice, primitive shallow cup-like synaptic troughs present at birth had developed to anastomosing grooves containing both pit-like and slit-like junctional folds (JFs) during the 2nd postnatal week. At the 35th day, the SNAs had developed to almost the adult forms, consisting of labyrinthine synaptic grooves with exclusively slit-like JFs. In the mdx mice, the SNAs showed transformation similar to those in the normal mice until the 35th postnatal day. After this period, SNAs with a number of cup-like depressions occurred and increased in number. These morphological changes seemed to be found on regenerating muscle fibers after necrosis, probably indicating the remodelling of their NMJs.

Animals↗
PubMed1997

Argon laser irradiation to the semicircular canal.

In order to elucidate the effects of argon laser irradiation on the lateral semicircular canal of the guinea pig, the vestibular labyrinth was histologically studied after irradiation, using the conventional celloidin method. Irrigation of the external meatus with ice water was used to evaluate the function of the semicircular canal by recording caloric nystagmus. When irradiation was performed, a laser probe was approximated to the lateral canal, 0.5 to 1 mm away from the surface of the canal. Each time, power applied was 1.0 W on the dial of the laser machine. The duration of irradiation was 0.5 s. The lateral canal was irradiated one to 15 times. Twenty-five to 87 days after irradiation, the temporal bones were fixed in Heidenhein-Susa solution, removed, and subjected to celloidin processing. The irradiated bony wall of the lateral canal demonstrated charring. Lucent areas were observed around and under the charred area. The semicircular duct showed shrinkage with disappearance of the trabecular mesh. New bone formation was observed along the endosteum of the irradiated area. The lateral canal was completely occluded by ossification with or without fibrosis when sufficient energy was applied. The anterior and posterior canals were normal. Caloric tests using 5 mL of ice water for 5 s failed to elicit nystagmus on the irradiated side.

Animals↗
PubMed1997

[A case of a surgically treated extracranial internal carotid artery saccular aneurysm].

Extracranial internal carotid artery aneurysm is rare. Most cases are due to spontaneous or traumatic dissection of the cervical internal carotid artery. Here we report a case of surgically treated extracranial internal carotid artery (ICA) aneurysm. A 74-year-old man noticed a pulsatile mass just below the left mandibular angle. Intravenous digital subtraction angiography revealed multiple aneurysms in the systemic arteries, including the aortic arch, abdominal aorta and left extracranial ICA. It was decided to treat the aneurysms of the aortic arch and of the abdominal aorta conservatively. Cerebral angiography, however, showed a saccular aneurysm which projected latero-posteriorly at the C2 level of the left extracranial ICA. Although the patient had no previous ischemic event, we decided to treat this aneurysm surgically in view of the risk of cerebral ischemia caused by intraaneurysmal thrombus formation or rupture of the aneurysm by neck injury. The operation was performed under mild hypothermal general anesthesia. Electroencephalography was carried out during the operation. A skin incison was made from the anterior border of the sternocleidomastoid muscle to the pretragal region to expose the parotid gland. This skin incision, elevation of the parotid gland and division of the digastric muscle were useful for exposing the distal portion of the extracranial ICA. After trapping of the aneurysm, it was punctured and collapsed by aspiration and the dome was excised at its neck. The ICA was then reconstructed by suturing the cut neck of the aneurysm. Patency of the ICA was confirmed by postoperative angiography. The postoperative course was smooth except for hoarseness, which was caused by damage to a minor branch of the vagus nerve during exposure of the aneurysmal dome.

Aged↗
PubMed1997

[A case of simultaneous bilateral carotid occlusion].

Cases of bilateral cartoid occlusion have often been reported in the literature, but most of them were not examples of simultaneous bilateral carotid occlusion. Simultaneous bilateral cartoid occlusion appears to be rare, so we report one such case in this paper. A 68-year-old woman suddenly became unconscious, and was delivered to our hospital by ambulance. On arrival, she was comatose and showed decerebrate rigidity upon pain stimulation. Results of CT scan were normal, but cerebral angiography showed bilateral internal carotid artery occlusion at the carotid bifurcation. The patient was treated with urokinase and osmotic diuretics, but these were not effective and she died on the eleventh day after admission. Autopsy revealed that the bilateral internal carotid artery was occluded by fresh thrombi at the carotid bifurcation. The mitral valve was thickened by fibrous adhesion, and this was thought to indicate mitral stenosis. MRI before onset had shown flow void sign in the bilateral internal carotid artery. From the clinical course, and radiological and autopsy findings, we consider this case to be one of simultaneous bilateral carotid occlusion due to cardiogenic thrombi. Previous cases of bilateral carotid occlusion are reviewed and discussed.

Aged↗
PubMed1997

[Familial astrocytoma associated with von Recklinghausen's disease: report of two cases].

Two cases of astrocytoma associated with von Recklinghausen's disease (neurofibromatosis type; NF-1) were reported. The first case wes a 60-year-old man who had been diagnosed as von Recklinghausen's disease on the basis of skin findings. Magnetic resonance imaging (MRI) showed a tumor in the left temporal lobe. Partial removal was performed with neuronavigator, and because of the existence of Rosenthal fiber the histological diagnosis was pilocytic astrocytoma. Radiation therapy was performed. The second case was a 6-year-old boy suffering from headache and left hemiparesis including his face. MRI showed a tumor with a cyst in the right thalamus and obstructive hydrocephalus. Initially CT-guided stereotactic biopsy was performed, and the histological diagnosis, on the basis of increased cellularity, pleomorphism and nuclear atypia without necrosis or vascular proliferation, was anaplastic astrocytoma. Radiation and chemo-immuno therapy were carried out after V-P shunt. It is well known that von Recklinghausen's disease (NF-1) is often associated with optic glioma (5-36%). In the literature, the glioma seldom occurs in other parts of the brain, supratentorial glioma especially is rare. Only two familial cases of supratentorial glioma associated with von Recklinghausen's disease have been reported. The prognosis of supratentorial glioma associated with NF-1 was poor in these reports. In this paper, the diagnostic and therapeutic problems are discussed.

Astrocytoma↗
PubMed1997

[A long-term surviving case with invasive thymoma undergone 4 times operations for tumor recurrences].

We reported a long-term survivor with invasive thymoma associated with myasthenia gravis. The patient underwent operations 4 times for these 13 years. At the third and fourth operation, the tumor was resected after preoperative neo-adjuvant chemotherapy with cisplatin and adriamycin, and postoperative radiotherapy was added. Her postoperative course was uneventful, and she has been alive. Our strategy for invasive thymoma is that tumors which include both primary and recurrent lesions are removed as completely as possible, and that postoperative radiotherapy is added for stage II, III and IV in Masaoka's classification, and preoperative neo-adjuvant chemotherapy for stage III and IV. We believe that these multidisciplinary treatments and long term follow-up lead good results without harm to quality of life.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Morphologic differences of the vascular buds in the vertebral endplate: scanning electron microscopic study.

STUDY DESIGN: Vascular buds in rabbit vertebral endplates were examined by scanning electron microscopy of corrosion casts. OBJECTIVES: To examine morphologic differences between vascular buds in two regions of the vertebral endplate (inner anular and nucleus pulposar). SUMMARY OF BACKGROUND DATA: Vascular buds are specific structures present at the vertebral endplate that are important as nourishing channels. There is a significant difference in permeability between the lateral portion (inner anular) and the central portion (nucleus pulposar) of the endplate, the latter usually being permeable and the former being impermeable. Morphologic differences between vascular buds in the two regions have not been investigated previously. METHODS: Eight 20-week-old rabbits were used. Vascular buds in rabbit vertebral endplates were examined by scanning electron microscopy of corrosion casts. RESULTS: The vascular buds in the region of the inner anulus form simple loops, but those in the area near the nucleus pulposus exhibit swollen and complex coil-like loops. Although they differ structurally, the average number of vascular buds per area does not vary between the two regions. CONCLUSIONS: We suggest that the morphologic difference between the vascular buds in the two regions (inner anular and nucleus pulposar) plays a principal role in permeability at the endplate.

Animals↗