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Biomedical subjects

M Kobayashi

Publications and source records attributed to M Kobayashi.

At least 487 records · Page 27Linked to original sources
PubMed2000

Hepatic vascular side effects of styrene maleic acid neocarzinostatin in the treatment of hepatocellular carcinoma.

Styrene-maleic acid neocarzinostatin (SMANCS) sometimes causes hepatic vascular side effects, including arterial stricture, obstruction, and arterio-portal shunt. A total of 128 intra-arterial SMANCS injection treatments, performed for 89 patients with hepatocellular carcinoma, were analyzed to determine the relationship between angiographic findings and subsequent hepatic vascular injuries. After SMANCS therapy, hepatic arterial stricture or obstruction occurred in 5 patients (5/128; 3.9%), arterio-portal shunting in 12 (12/128; 9.4%), liver shrinkage in 4 (4/128; 3.1%), and cholangitis or biloma in 2 (2/128; 1.6%). Among 23 patients whose plain abdominal X-ray films just after SMANCS injection showed Lipiodol retention in the hepatic artery, 5 patients developed arterial obstruction, 10 developed arterio-portal shunt, and 2, cholangitis or biloma. Among 26 patients with Lipiodol retention in the portal vein, 4 developed hepatic lobe atrophy with aggravation of liver function. Among 3 patients with Lipiodol retention in both the hepatic artery and the portal vein, 1 developed arterio-portal shunt. In 76 treatments without excessive Lipiodol retention, only 1 of the patients developed arterio-portal shunt. Excessive retention of Lipiodol in hepatic vascular beds just after SMANCS therapy was significantly associated with future vascular side effects (22/52 vs 1/76; P < 0.0001). Lipiodol retention in arteries just after SMANCS injection was closely associated with subsequent arterial obstruction or arterio-portal shunt, and Lipiodol retention in the portal vein was related to subsequent hepatic lobe atrophy.

Adult↗
PubMed2000

Progressive and sufficient decrease of hepatitis B core antibody can predict the disappearance of hepatitis B virus DNA in Japanese patients with hepatitis B surface antigen clearance.

The aim of this study was to elucidate the relationships among serum levels of hepatitis B virus (HBV) DNA, periods after hepatitis B surface (HBs) antigen clearance, and the titer of hepatitis B core (HBc) antibody in 200-fold diluted serum. Twelve patients who had clearance of HBs antigen from serum were studied. Five patients had not received any treatment (group A), and seven had received prednisolone withdrawal therapy. The patients in groups A and B were followed up for 86 months and 108 months (median), respectively. Serum HBV was measured by the nested polymerase chain reaction method. In both groups, serum HBV tended to become gradually undetectable after HBs antigen clearance. The positive rate of HBV in the sera 5 years or more after HBs antigen clearance was significantly lower than that in the sera at less than 5 years, both in group A (P = 0.004) and group B (P = 0.010). In both groups, the titer of HBs tended to decline every year after HBs antigen clearance. HBV was still detectable in the sera of some patients for a long period of time after they showed seroconversion to HBs antibody. The results suggest that detection of HBV was difficult in sera with an HBc titer of 30% or lower and at more than 5 years after HBs antigen clearance in both groups. It is important to note that HBV DNA rarely exists in the serum, even when HBs antigen and HBc are both negative.

Adolescent↗
PubMed2000

Increased response rate to interferon therapy after a second course in hepatitis C patients who show relapse after the initial course.

Some patients with chronic hepatitis C become HCV-RNA seronegative during interferon (IFN) therapy. However, about one-half of these patients show a relapse, evident by high serum alanine aminotransferase (ALT) level. In some patients with biochemical relapse, the serum HCV-RNA level becomes low immediately after the ALT relapse. Here, we assessed the changes in serum HCV-RNA level in patients with ALT relapse after IFN therapy, and evaluated the efficacy of a second course of IFN, started at the recovery stage after ALT relapse. Two hundred and seventy-seven patients who showed HCV-RNA seronegativity by reverse transcription nested-polymerase chain reaction (RT nested-PCR) and normalization of ALT during the initial IFN therapy, and had positive HCV-RNA with ALT relapse (> 100 IU/l) within 3 months after completion of the initial IFN course were enrolled in this retrospective study. Two hundred and sixty patients were followed-up without further IFN retreatment after the ALT relapse (group 1), and 17 patients received another 6-month course of IFN after the ALT relapse (group 2). The median level of serum HCV-RNA, determined with a branched DNA probe assay (version 1; Chiron-Dai-ichi Kagaku Tokyo, Japan), in group 1 was 3.1 Meq/ml before IFN therapy, 1.3 Meq/ml at the time point of the ALT peak after the completion of IFN therapy, and 0.7 and 2.6 Meq/ml at 2-4 and 6-8 weeks after the ALT peak, respectively. The serum HCV-RNA level at 2-4 weeks after the ALT peak was lower than that before IFN therapy. The eradication rate of HCV-RNA (complete response; CR) in group 2 (47.1%; 8/17) was significantly higher than that in group 1 (1.5%; 4/260; P < 0.001). In conclusion, our data suggested that: (1) patients who showed biochemical relapse after initial IFN therapy had a significantly lower serum HCV-RNA level at recovery after ALT relapse compared with that before initial IFN therapy. (2) A high response rate was noted after a second course of IFN administered at the recovery stage of the ALT relapse, compared with patients without IFN retreatment.

Adult↗
PubMed2000

Baculovirus infection blocks the progression of fat body degradation during metamorphosis in Bombyx mori.

The effect of baculovirus infection into silkworm pupa particularly on programmed fat body degradation during metamorphosis was investigated. Pupal fat body degradation did not occur following infection with Bombyx mori nucleopolyhedrovirus (BmNPV). There were no histolytic differences between the fat body tissues of mock and BmNPV infected papae until 48 h postinfection (p.i.). Between 48 and 72 h p.i., significant differences were observed. In order to determine whether the histolysis of fat body was due to apoptosis, genomic DNAs were purified at various p.i. times and analyzed. Rapid genomic DNA fragmentation was observed at 24 and 48 h after pupation in both mock and BmNPV infected pupae. However, BmNPV infection clearly inhibited DNA fragmentation and ladder formation at 72 h and later times p.i. Furthermore, pulse-labeling analysis showed that BmNPV infection restored protein synthesis in fat body cells. These results suggested that fat body degradation during pupal-adult development was due to apoptosis, and that BmNPV was able to evoke a cellular response in these cells.

Animals↗
PubMed2000

Non-traumatic osteonecrosis of the femoral head treated with transtrochanteric anterior rotational osteotomy combined with vascularized iliac bone grafting.

A 49-year-old Japanese man who had non-traumatic osteonecrosis of the femoral head with a wide necrotic lesion received transtrochanteric anterior rotational osteotomy combined with vascularized iliac bone grafting. After the bone graft (6 x 1.5 cm) was collected, the femoral head was anteriorly rotated by 90 degrees. A bone tunnel of 1.2 cm in diameter was prepared on the necrotic lesion adjacent to the intact area from the anterior part of the femoral neck to inside the femoral head. The bone graft was trimmed to the size of this bone tunnel, and inserted up to immediately below the articular surface. In the monitoring using T1-weighted magnetic resonance imaging (MRI), the low signal-intensity area between the bone graft and intact area had disappeared, and a high signal-intensity area on the weight-bearing portion of the femoral head had extended. With modifications on the insertion point of the bone graft, transtrochanteric anterior rotational osteotomy combined with vascularized iliac bone graft would be a useful means to preserve the femoral head in large non-traumatic osteonecrosis of the femoral head.

Bone Transplantation↗
PubMed2000

Morphological study of the regeneration mechanism of acetic acid-injured colon crypts in the rat.

The regeneration mechanism of injured rat colonic mucosa with 1% acetic acid was certified in this study. The injured colons were studied periodically on experimental days 1, 3, 5, 7, 15, and 20 with light and scanning electron microscopy. Specimens were examined in paraffin sections stained with hematoxylin and eosin; crypts were isolated with the HCl digestion method; and three-dimensional stromal collagen tissue was prepared with the NaOH cell maceration method. Damage to the mucosal and submucosal layers peaked between the 1st and 3rd days with edema, regeneration, necrosis, and inflammation. The edema and inflammation subsided, and mucosal atrophy and crypt reduction remained at around 1 week. At 2 weeks the mucosa became thick, and crypts showed many branches in their lower two-thirds; and by 3 weeks the mucosa had recovered to almost normal. The ratio of number of crypts at the base and surface was almost 1.5 on the 15th day and 1.0 on the 20th day, suggesting that each branch progresses upward to create an independent crypt. We believe that the fission mechanism plays an important role in crypt repair after acetic acid injury of the colonic mucosa. As the proliferative zone of the colonic crypt is localized at the crypt base, fission of the crypt starting at the base and progressing up to the surface is the most reasonable and efficient mechanism for repair by increasing the number of crypts.

Acetic Acid↗
PubMed2000

Anomalies of inferior vena cava and left renal vein: risks in aortic surgery.

Although most aortic surgery is now routinely performed without incident, major venous anomalies can cause unexpected bleeding. In the last 6 years, 4 of 166 patients undergoing abdominal aortic surgery at our institution were found to have a major venous anomaly, including a double inferior vena cava (2), a preaortic iliac vein confluence (1), and a circumaortic renal collar (1). The 3 men and 1 woman had a mean age of 62.3 years (range, 56 to 68 years). All four patients underwent surgery for an abdominal aortic aneurysm. Preoperative imaging revealed all of the venous anomalies except for the renal collar. Unexpected venous injuries complicated the operation in one patient who had a double inferior vena cava and an inflammatory abdominal aortic aneurysm and in the patient with the circumaortic renal collar. Major venous anomalies are rarely encountered in patients undergoing aortic surgery. Preoperative assessment and intraoperative awareness are important to prevent unexpected venous injuries. Patients with an anomaly of the left renal vein and an inflammatory abdominal aortic aneurysm are at a particularly high risk.

Aged↗
PubMed2000

Application of solid-phase extraction to the analysis of the isomers generated in biodesulfurization against methylated dibenzothiophenes.

A solid-phase extraction (SPE) technique was applied to analyze and characterize the biodesulfurization reactions against asymmetrically methylated dibenzothiophenes (mDBTs) such as 1-, 2-, 3- and 4-methyldibenzothiophenes present in fossil fuels. Recently, we found that these mDBTs are efficiently degraded by the bacterial strain, Rhodococcus erythropolis KA2-5-1. Separation and concentration of the microbial desulfurization products from each of the mDBTs could be carried out with high efficiency and reproducibility by the SPE procedure. These desulfurization products were identified using the SPE technique combined with GC, GC-atomic emission detection, GC-MS and 1H nuclear magnetic resonance spectroscopy. The analytical data obtained suggested that the desulfurization reactions against mDBTs by this bacterial strain may occur through specific carbon-sulfur bond-targeted cleavages that can be affected by the positions of methyl groups.

Chromatography, Gas↗
PubMed2000

Renal disease in women with severe preeclampsia or gestational proteinuria.

OBJECTIVE: To identify women with severe preeclampsia or severe gestational proteinuria at high risk of having underlying renal disease. METHODS: Between 1980 and 1999, 86 Japanese women who had severe hypertension, severe proteinuria, or both during pregnancy had postpartum needle biopsies of their kidneys. Diagnoses before biopsies were severe preeclampsia in 74 women and severe gestational proteinuria in 12. We compared clinical characteristics, such as antepartum hematuria and postpartum proteinuria, and maternal and neonatal outcomes with regard to presence of renal disease. RESULTS: Nineteen of 86 women (22.1%, 95% confidence interval [CI] 13.9%, 32. 3%) were diagnosed with underlying renal disease. Immunoglobulin A nephropathy was present in 12. Women with renal disease had a significantly earlier onset of proteinuria than those without (median 11 versus 32 weeks' gestation, P <.001). Eighteen of 19 women with renal disease had proteinuria, hypertension, or both before 30 weeks' gestation. Ten of 12 women with severe gestational proteinuria (83.3%, 95% CI 51.6%, 97.9%) had underlying renal disease. Eight of the 19 women had antepartum hematuria, and seven had elevated serum immunoglobulin A levels. In women with severe preeclampsia, onset before 30 weeks' gestation was the best predictor of underlying renal disease (odds ratio 34.1, 95% CI 3.8, 304.5). Women with renal disease had lower rates of severe hypertension (nine of 19 versus 59 of 67, P <.01) and small-for-gestational-age infants (four of 19 versus 34 of 67, P <.05) than those without renal disease. CONCLUSION: Women who had gestational proteinuria or preeclampsia before 30 weeks' gestation were more likely to have had underlying renal disease.

Adult↗
PubMed2000

Gibberellin biosynthesis: metabolic evidence for three steps in the early 13-hydroxylation pathway of rice.

[14C4]GA53, [14C4]GA44, and [2H2/14C4]GA19 were injected separately into seedlings of rice (Oryza sativa) using a dwarf mutant (d35) that has low levels of endogenous gibberellins (GAs). After 8 h incubation, the shoots were extracted and the labeled metabolites were identified by full-scan gas chromatography mass spectrometry (GC-MS) and Kovats retention indices (KRIs). Our results document the metabolic sequence, GA53-->GA44-->GA19-->GA20 and the presence of endogenous GA53, GA44, GA19, GA20 and GA1. Previous metabolic studies have shown the presence of the step, GA20-->GA1 in rice. Taken together, the data establish in vegetative shoots of rice the presence of the early 13-hydroxylation pathway, a pathway that originates from GA12 and leads to bioactive GA1.

Gas Chromatography-Mass Spectrometry↗
PubMed2000

Expression of thyroid transcription factor-1 (TTF-1) in human C cells and medullary thyroid carcinomas.

Thyroid transcription factor-1 (TTF-1) has been known to regulate the transcriptional activity of thyroid-specific genes in thyroid follicular cells. We recently identified TTF-1 mRNA expression in rat thyroid C cells. The current study was undertaken to elucidate how TTF-1 is expressed in human C cells and medullary thyroid carcinomas (MTCs), and how this expression influences the functions and clinical behavior of these cells. By immunohistochemistry, the nuclei of normal and hyperplastic C cells distinctively reacted with antibody against TTF-1, whereas the immunostaining intensity in C cells was rather weak and heterogeneous in comparison with that in follicular cells. Identical TTF-1 immunoreactivity was observed in all 15 MTC specimens examined. The reaction intensity did not depend on tumor patterns or cell features. In nonisotopic in situ hybridization, an antisense riboprobe clearly hybridized the cytoplasms of C cells and MTC cells, which concurrently showed immunohistochemical positivity for calcitonin. Northern blot analysis indicated a marked hybridization with TTF-1 mRNA of approximately 2.3 kb in an MTC specimen. Furthermore, the presence of TTF-1 mRNA was confirmed by reverse transcription polymerase chain reaction (RT-PCR) in the human MTC cell line, TT. Our results suggest that human thyroid C cells and MTC cells express TTF-1 in connection with their functional ability. Therefore, TTF-1 expression can be a functional marker not only for follicular cells and follicular cell tumors but also for C cells and medullary C cell carcinomas.

Adolescent↗
PubMed2000

Postoperative hyperperfusion syndrome in elderly patients with chronic subdural hematoma.

BACKGROUND: Temporary acute agitated delirium is a frequent complication after surgery for chronic subdural hematoma (CSH) in elderly patients. To clarify the pathogenic mechanism underlying this complication, we measured cerebral blood flow before and after surgery in elderly patients with CSHs. METHODS: Twenty-seven patients aged 75 years or older with unilateral CSH underwent treatment involving a single burr hole craniostomy with continuous catheter drainage. Cerebral blood flow was measured using single photon emission computed tomography 1 day before surgery, and at 1 hour and 24 hours after surgery. Acute agitated delirium was diagnosed by the characteristic behavioral abnormality. RESULTS: SPECT imaging 1 hour after surgery demonstrated hyperperfusion in the cerebral cortex beneath the CSH in 14 patients (51.9%). Of these 14 patients, five showed acute agitated delirium a few hours after surgery that persisted for 10 to 12 hours. A hematoma was detected in the right hemisphere in all five patients. Hyperperfusion was significantly more intense in patients with acute agitated delirium both 1 hour and 24 hours after surgery than in patients (n = 9) without acute agitated delirium. Moreover, mean arterial blood pressure during the first postoperative hour was significantly higher in patients with acute agitated delirium. CONCLUSION: In elderly patients with CSH, intense and prolonged hyperperfusion after surgery induces temporary acute agitated delirium. This postoperative hyperperfusion syndrome is exacerbated by hypertension.

Aged↗
PubMed2000

Tumor-targeted chemotherapy with SMANCS in lipiodol for renal cell carcinoma: longer survival with larger size tumors.

OBJECTIVES: To evaluate the anticancer effects of a lipophilic macromolecular anticancer agent, poly(styrene-co-maleic acid)-conjugated neocarzinostatin (SMANCS), dissolved in a lipid contrast medium (Lipiodol) given via the renal artery to patients with renal cell carcinoma. METHODS: Among 467 patients with renal cell carcinoma treated between April 1984 and March 1993, 191 were treated with SMANCS dissolved in a lipid contrast medium (a 3:2 mixture of Lipiodol F and Lipiodol Ultrafluid; Lpd). Selective arterial infusion of SMANCS/Lpd was performed at a dose of 1.0 or 1. 5 mg/mL. The infusion was repeated at intervals of about 2 weeks or longer, but the doses and the total number of infusions varied among patients, according to results of computed tomography analysis. RESULTS: Statistical analysis was performed for 415 patients who met the criteria of this study. Twenty-six surgical patients with metastases who underwent infusion therapy of SMANCS/Lpd for primary lesions showed 3 and 5-year survival rates of 23.0% and 12.8%, respectively; the rates were 19.3% and 9.7% in 31 patients who did not receive SMANCS infusion therapy. In 125 surgical patients without metastases who underwent SMANCS/Lpd infusion, the 5 and 10-year survival rates were 83.0% and 75.2%, respectively, whereas rates of 84.6% and 78.9% were observed in 199 surgical patients whose median tumor size was significantly smaller, however, than the SMANCS/Lpd infusion group. The maximal tumor diameter at the beginning of treatment was significantly larger (mean diameter 70.8 mm) in the SMANCS/Lpd infusion group than in the noninfusion group (59.1 mm). The survival rate was statistically better for patients with tumors of 100 mm diameter or larger in the SMANCS/Lpd infusion group (P <0.05): 5 and 10-year survival rates were 70.4% and 61.6%, respectively, for the infusion group and 64.6% and 50.9% for the group receiving no drug. In patients with larger tumor (greater than 110 mm), the survival rate at 13 years was 75% in the SMANCS/Lpd infusion group and 0% in the surgery group. CONCLUSIONS: Arterial infusion therapy with SMANCS/Lpd appears to be effective for large renal cell carcinoma without metastases in conjunction with surgery.

Adolescent↗
PubMed2000

Strengthening of glass-ionomer cement by compounding short fibres with CaO-P2O5-SiO2-Al2O3 glass.

The purpose of this study was to determine if short fibres of CaO-P2O5-SiO2-Al2O3 (CPSA) glass possessing a particular aspect ratio (length/diameter) could be used as a reinforcing agent for glass-ionomer cement. The powder of a commercial glass-ionomer cement (not resin modified) was mixed with variously sized CPSA glass short fibres before mixing with the liquid of the glass-ionomer cement. The mixed powders containing 60 mass% CPSA glass short fibres (diameter, 9.7 +/- 2.1 microm, aspect ratio, 5.0 +/- 0.9) obtained maximum values of 18 and 35 MPa for the diametral tensile strength (DTS) and flexural strength (FS) of set cements, respectively, after 24 h. These DTS and FS values were 1.8 and 4.5 times larger, respectively, than those of the set glass-ionomer cement not containing short fibres. Moreover, it was found that the addition of CPSA glass short fibres was remarkably more effective in the strengthening than electric glass (a typical glass fibre) short fibres. The results suggested that the CPSA glass short fibres acted as a reinforcing agent for strengthening the glass-ionomer cement, because of the shape of short fibres and reactivity between the mixing liquid and short fibres.

Dental Cements↗
PubMed2000

Biological and mechanical properties of PMMA-based bioactive bone cements.

We reported previously that a bioactive PMMA-based cement was obtained by using a dry method of silanation of apatite-wollastonite glass ceramic (AW-GC) particles, and using high molecular weight PMMA particles. But handling and mechanical properties of the cement were poor (Mousa et al., J Biomed Mater Res 1999;47:336-44). In the present study, we investigated the effect of the characteristics of PMMA powder on the cement. Different cements containing different PMMA powders (CMW1, Surgical Simplex, Palacos-R and other two types of PMMA powders with Mw 270,000 and 1,200,000) and AW-GC filler in 70 wt% ratio except Palacos-R (abbreviated as B-CMW1 and B-Surg Simp, B-Palacos 50 [50 wt% AW-GC filler] and B-Palacos 70 [70 wt% AW-GC filler], B-270 and B-1200) were made. Dough and setting times of B-CMW1, B-Surg Simp B-270 and B-1200 were similar to the commercial CMW1 cement which did not contain bioactive powder (C-CMW1), but B-palacos which contained large PMMA beads with high Mw had delayed setting time. B-270 had the highest bending strength among the tested cements. After 4 and 8 weeks of implantation in the medullary canals of rat tibiae, the bone-cement interface was examined using SEM. The affinity index of B-1200 was significantly higher than the other types of cements. B-270 showed good combination of handling properties, high mechanical properties and showed higher bioactivity with minimal soft tissue interposition between bone and cement compared with commercial PMMA bone cement. This may increase the strength of the bone-cement interface and increase the longevity of cemented arthroplasties.

Animals↗