Search PubMed⌕ Search

Biomedical subjects

H Baba

Publications and source records attributed to H Baba.

At least 217 records · Page 12Linked to original sources
PubMed1995

A new function of Nm23/NDP kinase as a differentiation inhibitory factor, which does not require it's kinase activity.

We recently identified a differentiation inhibiting factor (I-factor) in mouse myeloid leukemia M1 cells as a murine homolog of nm23-H2/nucleoside diphosphate kinase (NDPK)-B gene product. We examined the I-factor activities of several authentic nm23/NDPK proteins, i.e. recombinant rat NDPK alpha and beta, recombinant mouse nm23-M1 and -M2, and recombinant human nm23-H1 and -H2 containing a mutant nm23-H2His protein lacing NDPK activity. Almost all these nm23/NDPK proteins showed I-factor activity. Moreover, to understand the active domain exhibiting I-factor activity of nm23-H2 protein lacking NDPK activity, we have investigated the I-factor activities of some truncated nm23-H2 proteins. The truncated nm23-H2 protein containing N-terminal peptide 1-60 retained the I-factor activity. These results provide the first evidence for a function of nm23/NDPK as a differentiation inhibiting factor in leukemic cells, that is independent of its NDPK activity and dependent on the presence of N-terminal peptide.

Animals↗
PubMed1995

Inefficient membrane targeting, translocation, and proteolytic processing by signal peptidase of a mutant preproparathyroid hormone protein.

A preproparathyroid hormone allele from a patient with familial isolated hypoparathyroidism was shown to have a single point mutation in the hydrophobic core of the signal sequence. This mutation, changing a cysteine to an arginine codon at the -8 position of the signal peptide, was associated with deleterious effects on the processing of preproparathyroid hormone to proparathyroid hormone in vitro. To examine the biochemical consequence(s) of this mutation, proteins produced by cell-free translation of wild-type and mutant cRNAs were used in assays that reconstitute the early steps of the secretory pathway. We find that the mutation impairs interaction of the nascent protein with signal recognition particle and the translocation machinery. Moreover, cleavage of the mutant signal sequence by solubilized signal peptidase is ineffective. The consequence of this mutation on processing and secretion of parathyroid hormone is confirmed in intact cells by pulse-chase experiments following transient expression of the mutant protein in COS-7 cells. The inability of the mutant signal sequence, however, to interfere with the targeting and processing of other secreted proteins does not support obstruction of the translocation apparatus as the mechanism underlying the dominant mode of inheritance of hypoparathyroidism in this family.

Alleles↗
PubMed1995

Gastric carcinoma in patients over 70 years of age.

The clinicopathological features and prognosis of gastric cancer in 344 patients aged 70 years or older who underwent gastrectomy between 1965 and 1990 were determined. Over the years the mean size of the tumour decreased, differentiated tumour tissue was more common, depth of penetration was less prominent, lymphatic and vascular involvement was less frequent, and the rate of lymph node metastasis and peritoneal dissemination decreased. Extensive lymph node dissection was more frequently carried out and the rate of curative resection rose. Survival rates improved with early detection of gastric cancer and there was no increase in operative morbidity and mortality rates. As age alone is not a contraindication to surgery for patients with gastric carcinoma, early detection of the lesion and surgical treatment are expected to increase the survival of elderly patients with this malignancy.

Aged↗
PubMed1995

Surgical treatment of patients with gastric carcinoma and duodenal invasion.

We retrospectively examined the extent of invasion of gastric cancer with duodenal involvement in order to design pertinent surgical procedures that may lead to a better prognosis. Examinations were made on excised tissues from 650 patients who underwent gastrectomy for adenocarcinoma in the gastric antrum. In 95 patients, the cancer cells extended to beyond the pyloric ring. Spread into the duodenum was limited to within 2 cm in 76% of the patients and to within 3 cm in 81%. In addition to high rates of metastasis in group 1 and 2 lymph nodes, some group 3 lymph nodes also were involved, and more frequently so in cases with duodenal invasion than in those without such invasion (P < 0.01). The 5-year survival rate for patients with duodenal invasion was 35.4% when a curative resection was done. For patients with advanced adenocarcinoma with duodenal invasion, gastrectomy with resection of 3-4 cm of the duodenum and dissection of group 1, 2, and 3 lymph nodes were recommended.

Adenocarcinoma↗
PubMed1995

Revision surgery for lumbar disc herniation. An analysis of 45 patients.

We reviewed 45 patients who had undergone repeated open operations for lumbar disc herniation. There were 26 men and 19 women with a mean follow up of 4.3 years. Twenty-four patients had had one previous discectomy, 12 had 2, and 9 had 3 or more; 11 needed a fusion without instrumentation. Residual or re-extruded disc hernias, either sub- or transligamentous, were frequently found at revision. Good to excellent results were obtained in 64%. Those who had a first-time revision had earlier improvement and better results. Complete removal and a thorough search for herniated disc material is essential when carrying out the initial operation for extruded or sequestrated herniation. At revision, removal of as much as possible of the remaining nucleus and annulus, but with minimal invasion of the posterior elements, is crucial for improving the outcome.

Adolescent↗
PubMed1995

Flexibility and alignment of the cervical spine after laminoplasty for spondylotic myelopathy. A radiographic study.

The long term effects of laminoplasty on cervical movement and alignment were investigated by radiography and CT scans in a study of 56 patients with multisegmental myelopathy who had undergone a C3 to C7 open-door laminoplasty. Follow up averaged 5.8 years. Satisfactory neurological improvement occurred in 73%. Cervical flexion decreased by 35% and extension by 57%; the decrease of both movements was statistically significant. Decreased vertebral slip, as well as slightly reduced lordosis, was seen after operation. Increase in measured canal size after operation and at follow up was 48% and 40%; 8% of the expanded canal size was lost at the last follow up. Expansive open-door laminoplasty leads to a better neurological prognosis in this group of patients, while maintaining an increase in canal size and preserving spinal stability.

Aged↗
PubMed1995

Lumbar radiculopathy associated with anterior intraspinal bony lesions.

Thirty-one patients underwent posterior decompression for anterior intraspinal bony lesions which were causing symptoms. The diagnoses were a displaced apophyseal endplate, vertebral corner bulge, and an ossified posterior longitudinal ligament or disc. Symptoms were caused by associated lumbar disc herniations or by gradual impingement by the bony lesion on neural tissue. The success rate after operation was 84%. Anterior spinal canal compromise by bony lesions can be treated by decompression through a posterior approach with minimal destruction of the laminae and facets.

Adult↗
PubMed1995

Osteoplastic laminoplasty for cervical myeloradiculopathy secondary to ossification of the posterior longitudinal ligament.

Forty-seven patients with cervical myeloradiculopathy due to ossification of the posterior longitudinal ligament were treated by laminoplasty. The spinal canal from C3 to C7 was opened en bloc unilaterally and a spacer bone graft inserted to separate the floating laminae. The average follow up was 7.3 years (range 5 to 11 years). Favourable results were obtained in 35 patients and even though they had serious postoperative symptoms those with advanced neurological symptoms before operation showed considerable improvement. Late results were poor in patients who had greater than 50% compromise of the spinal canal by the ossified lesion. Laminoplasty is a safer method of obtaining favourable late results in patients with involvement of more than 3 vertebrae, but in those with a more severe compromise of the spinal canal by ossification, additional anterior decompression may be necessary later.

Adult↗
PubMed1995

The cervical spine in the Klippel-Feil syndrome. A report of 57 cases.

We report 57 cases of the Klippel-Feil syndrome. Five had type I congenital cervical fusion, 48 type II and 4 type III. The symptoms and signs varied considerably. Patients with C2-C3 fusion often had symptoms associated with odontoid dysplasia and occipito-cervical instability. Twenty-one had progressive neurological symptoms and 19 were operated on: 3 had occiput-C3 posterior arthrodeses, 2 a single level fusion, 1 a laminectomy and anterior arthrodesis, and 13 had laminoplasties. Degenerative changes at the unfused segment and a narrow bony canal are high risk factors in the development of neurological compromise.

Adolescent↗
PubMed1995

Complete response of transverse colon carcinoma to S1, a new chemotherapy agent: report of a case.

A complete response to a new chemotherapeutic agent, S1, was achieved in a 64-year-old Japanese man with advanced transverse colon cancer. S1 is a combination of the agents tegafur, 5-chloro-2,4-dihydroxypyridine, and oxonic acid. Because the patient was considered to be a high operative risk due to his poor general condition, S1 was administered at 100 mg/day for 5 days/week over 12 weeks. However, as the serum carcinoembryonic antigen level continued to gradually increase, partial resection of the transverse colon was finally performed. Histopathological study of the resected specimen showed mucin pools in the colon wall with no residual viable cancer cells. No perioperative complications were recognized and the patient is now leading a normal life 6 months after his operation without any signs of recurrence.

Adenocarcinoma↗
PubMed1995

Genotoxic effect of griseofulvin in somatic cells of Drosophila melanogaster.

Griseofulvin (GF), a carcinogenic spindle poison, was tested in two types of somatic-cell assays of Drosophila melanogaster, one of which detects the induction of DNA damage and the other mutation/mitotic recombination. In both assays, GF was fed to tester larvae and genetic endpoints examined after emergence. In the wing spot test, trans-heterozygous flies carrying mwh and flr3 wing-hair mutations produced both significant and dose-dependent increases in the frequency of mwh single spots over the control level but no increase of twin spots. In the DNA repair test, double-mutant larvae carrying both mei-9(a) (excision repair-defective) and mei-41(D5) (postreplication repair-defective) mutations showed hypersensitivity to killing by GF compared with their DNA repair-proficient counterparts, suggesting that GF caused potentially lethal DNA damages which were efficiently repaired by the DNA repair-proficient but not -defective larvae. These lines of evidence clearly demonstrate that GF is genotoxic in somatic cells of Drosophila. It is noted that (1) GF-fed larvae showed a developmental delay and (2) surviving adult flies had morphological abnormalities in their eyes and wings.

Animals↗
PubMed1995

Effectiveness of extended lymphadenectomy in noncurative gastrectomy.

PURPOSE: We examined the efficacy of extended lymph node dissection for prolonging survival in macroscopically or histologically proven incurable gastric cancer. PATIENTS AND METHODS: We analyzed clinico-pathologic data on 119 patients with serosally invasive gastric cancer who underwent noncurative gastrectomy, with respect to the relation between the extent of lymphadenectomy and survival benefit. RESULTS: The 5-year survival rate was significantly higher among patients treated with extensive lymphadenectomy (R2/3) compared to simple gastrectomy (R1). Extensive lymphadenectomy significantly prolonged survival time even after noncurative gastrectomy in cases where there was no evidence of hepatic metastasis, peritoneal seeding, or extensive nodal metastasis beyond the tertiary lymph node, and regardless of the extent of direct invasion to adjacent organs. CONCLUSIONS: Gastrectomy combined with extended lymphadenectomy and/or resection of adjacent organs is recommended for gastric cancer patients without distant metastasis, even when the operation is histologically noncurative. Gastrectomy and perioperative intensive chemotherapy are called for when patients have distant metastasis.

Adenocarcinoma↗
PubMed1995

Lymphatic invasion and potential for tumor growth and metastasis in patients with gastric cancer.

BACKGROUND: Lymph node metastasis is a risk factor for the occurrence of peritoneal dissemination and liver metastasis in patients with gastric cancer. METHODS: We analyzed data on 324 patients with serosally invasive gastric cancer with respect to the relation between lymphatic invasion and potential for tumor growth and metastasis. All these patients were curatively treated in the Department of Surgery II, Kyushu University. RESULTS: Lymphatic invasion was evident in 214 patients, in whom vascular invasion was more frequent and the rate of lymph node metastasis was higher compared with patients with no lymphatic invasion. There was no difference in tumor size. The type of recurrence varied, and the prognosis was poor in patients with lymphatic invasion. The DNA ploidy pattern was higher, and the levels of proliferating cell nuclear antigen labeling and argyrophilic nucleolar organizer regions count were significantly higher in tumor tissues with lymphatic invasion than in those without invasion. CONCLUSIONS: Gastric cancers with characteristics of lymphatic invasion have higher proliferating activities, and metastases to distant organs are likely.

Cell Division↗
PubMed1995

Effect of lymph node dissection on the prognosis in patients with node-negative early gastric cancer.

BACKGROUND: Our objective was to evaluate the long-term benefit of R2/3 lymph node dissection compared with that of R1, even in node-negative cases. METHODS: We analyzed clinicopathologic data on 373 surgically treated patients with early gastric cancer and without microscopic nodal involvement. RESULTS: Five- and 10-year survival rates for patients treated with R2/3 gastrectomy were 97.3% and 95.4%, respectively. These values were significantly higher than the 90.1% and 81.1% noted for R1 gastrectomy (p < 0.01). Although no difference was found in morbidity and mortality, the incidence of death from a recurrence of the gastric cancer was significantly higher in patients treated with R1 gastrectomy than those with R2/3. Multivariate analysis with the Cox's proportional hazard model revealed patients' age and R2/3 gastrectomy to be independent prognostic factors in patients with node-negative early gastric cancer. CONCLUSIONS: These data show that prophylactic lymph node dissection can potentially prolong the survival time of patients with node-negative early gastric cancer by preventing a recurrence of the gastric cancer.

Age Factors↗
PubMed1995

The role of calcium deposition in the ligamentum flavum causing a cauda equina syndrome and lumbar radiculopathy.

Our report concerns five patients who underwent lumbar decompressive surgery for cauda equina syndrome and radiculopathy secondary to degenerative stenosis associated with calcium deposition in the ligamentum flavum. The resected ligamentum flavum showed diffuse to massive calcium crystal deposition with a histologically marked degeneration in the elastic fibres. Energy dispensive radiographic microanalysis confirmed the crystal to be calcium pyrophosphate dihydrate in all patients, hydroxyapatite mixed in three and calcium orthophosphate mixed in one. The deposition appeared to be a change that is associated with the degenerative process in the ligament and, in some cases having marked deposition in a localised event, it causes or aggravates the neurological symptoms.

Aged↗
PubMed1995

Anterior decompressive surgery for cervical ossified posterior longitudinal ligament causing myeloradiculopathy.

This paper reviews 88 patients (74 males and 14 females) who underwent anterior decompression and fusion for symptomatic ossified posterior longitudinal ligament of the cervical spine. Follow up averaged 8.5 years. Eighteen patients underwent one-vertebra, 59 two-vertebra, and 11 three-vertebra decompression with interbody fusion. The preoperative severity of symptoms significantly affected neurological recovery. Patients with three-vertebra spondylectomy showed significantly little neurological improvement. The return of patients to their previous activities as monitored at follow up was related to their preoperative neurological status. MRI findings appeared to be relevant to neurological recovery. Our findings suggest that anterior decompression is to be recommended for patients with less advanced preoperative symptoms and the involvement of one or two vertebrae.

Activities of Daily Living↗
PubMed1995

Symptomatic arachnoiditis ossificans of the thoracic spine. Case report.

This report describes a man aged 65 years who developed spastic paraparesis secondary to arachnoiditis ossificans in the thoracic spine. Over 35 years previously, in Southeast Asia, the patient had received repeated lumbar punctures in the treatment of meningitis possibly associated with malarial fever. He had multiple arachnoidal ossifications located at levels from T6 to T9 dorsal to the spinal cord which were well delineated by computed tomography. The lesions were completely extirpated by dorsal route surgery, and the patient had marked neurological improvement after surgery. Histology confirmed that the lesions showed mature bone that formed with an osseous marrow and trabeculae, and the lesions exhibited clusters of arachnoidal cells as well as the proliferation of osteoblasts surrounding the ossified area. Early diagnosis and surgical intervention, however, are mandatory in such cases, if the patient is to attain an acceptable degree of recovery.

Aged↗