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Biomedical subjects

S Hagiwara

Publications and source records attributed to S Hagiwara.

At least 19 recordsLinked to original sources
PubMed1992

Heavy chain variable (VH) region diversity generated by VH gene replacement in the progeny of a single precursor cell transformed with a temperature-sensitive mutant of Abelson murine leukemia virus.

Sequence analysis of a large number of DNA clones containing a functional heavy chain variable, diversity, and joining (VHDJH) complex generated by VH to VHDJH joining (VH gene replacement) in the progeny derived from a common precursor cell transformed with a temperature-sensitive (ts) Abelson murine leukemia virus (A-MuLV) indicates that endogenous VH gene replacement in vitro generates immunoglobulin gene joints distinct from those generated by the usual VH to DJH joining. Such joints keep the pentamer CAAGA at the 3' end of the donor VH segment and lack a recognizable D segment, as can be seen also in vivo. The results suggest that VH gene replacement participates in generating VH region diversity in vivo, as previously postulated. During the joining process, a unique VH gene was selected in all progeny cells, together with a single A nucleotide dominantly added to the junctional boundaries. The basis of these regulatory processes is discussed.

Abelson murine leukemia virus↗
PubMed1992

Altered calcium homeostasis accompanying changes of regional bone mineral during a very-low-calorie diet.

Calcium homeostasis during a very-low-calorie diet (VLCD) was examined. During the treatment, intact parathyroid hormone tended to decrease initially, bone Gla-protein increased significantly in the third week, and tartrate-resistant acid phosphatase decreased during the entire treatment. Serum ketone bodies showed significant correlations with intact parathyroid hormone and bone Gla-protein in some cases. Regarding bone mineral content, bone mineral content of the head increased while that of the legs decreased, resulting in no significant changes in total bone mineral content. These results suggest that VLCD treatment alters calcium homeostasis, which may cause regional bone mineral changes.

Acid Phosphatase↗
PubMed1992

High-density-lipoprotein metabolism during a very-low-calorie diet.

We examined the changes in high-density-lipoprotein (HDL) metabolism in eight female obese patients undergoing a very-low-calorie diet (VLCD). In the first half of the study, HDL cholesterol (HDL-C), apolipoprotein A-I (apo A-I), and apo A-II showed a parallel decrease. Although lipoprotein lipase (LPL) and hepatic lipase (HTGL) did not change, lecithin: cholesterol acyltransferase (LCAT) decreased. In the latter half of the protocol, HDL-C and apo A-I increased whereas apo A-II decreased, resulting in increased apo A-I-A-II ratios. There was no change in LPL, HTGL, or LCAT. LCAT and apolipoprotein composition may be important in HDL-C changes after VLCD.

Acyltransferases↗
PubMed1992

Postoperative neurosurgical infection and antibiotic prophylaxis.

The most suitable antibiotics for chemoprophylaxis in neurosurgery and risk factors for postoperative neurosurgical infection were investigated by retrospective analysis of 807 neurosurgical procedures in 566 patients between 1980 and 1989. Prophylactic antibiotics were administered intravenously for 6 or 7 postoperative days in all instances. The 807 operations were classified according to the antibiotics used into: 1) penicillin, 2) cephem-I, 3) cephem-II, 4) cephem-III, and 5) others. Postoperative neurosurgical infections occurred in 27 of 807 operations (3.3%), or 27 of 566 patients (4.8%). Hypertension and surgery performed in summer carried a significantly higher risk of infection. Diabetes mellitus, steroid administration, prolonged surgery, re-exploration, and surgery for hemorrhagic cerebrovascular diseases were associated with increased risk, but were not statistically significant. Infection rates by type of chemoprophylaxis were: 3.6% in the penicillin group, 3.7% in the cephem-I group, 1.7% in the cephem-II group, 5.7% in the cephem-III group, and 2.8% in the others group. This result indicates that the best choice for prophylactic antibiotic therapy may be a second-generation cephem.

Adolescent↗
PubMed1992

[Clinical and microbiological study of factors determining effective scaling and root planing].

The aim of the present study was to monitor longitudinally the clinical and microbiological parameters after root debridement in order to determine the factors affecting successful and unsuccessful results. Nine patients with moderate and severe periodontitis participated. Four sites of single root with over 5-mm periodontal pockets in each quadrant were selected. The oral hygiene was controlled in all patients, then root debridement was performed without anesthesia at the three sites of the quadrants every two weeks during eight weeks. The clinical parameters consisted of plaque index, gingival index, probing depth, clinical attachment level, bleeding on probing, tooth mobility and the value of gingival crevicular fluid (GCF). The microbiological parameters such as percentages of cocci, motile rods, non-motile rods and spirochetes and the number of microorganisms were examined and the percentages of black pigmented Bacteroides (BPB) and Actinobacillus actinomycetemcomitans as well as the number of anaerobic colonies were counted. The results demonstrated that a reduction in the probing depth was observed in all sites except four. The successful sites clinically showed a decrease of the probing depth and GCF value and, microbiologically, reduced percentages of the spirochetes and BPB. The results indicated that the decrease of the probing depth and GCF under 50 Periotoron units in coincidence with the bacterial reduction can be used to determine the successful response of root debridement.

Adult↗
PubMed1991

Decreased bone mineral density in diabetic patients on hemodialysis.

Renal osteodystrophy in hemodialyzed patients with DM-HD shows different features from that in non-DM,HD. Two studies were done. One was a comparison of BMD in 30 non-DM,HD patients and 30 DM-HD patients. The second was a comparison of possible factors affecting calcium metabolism in the higher and lower BMD groups (n = 20/21) in the DM-HD patients. BMD was measured by dual-energy X-ray absorptiometry (DEXA; Hologic QDR 1,000/W) in the third lumbar vertebra (L3), head, pelvis, and whole body. The BMDs of the DM-HD group were lower in these areas and whole body than that in the non-DM,HD group. A significant difference was found in the head BMD (p less than 0.05). In the second study, factors which may contribute to the differences in BMD were compared in the DM-HD patients divided into higher and lower BMD of the head. The group with higher head BMD had a value 110% of the mean value or more. Clinical and biochemical test results (age, the time since the first dialysis, body weight, the degree of obesity, height, serum calcium, serum phosphate, serum aluminum, serum c-PTH level and the dose of 1 alpha-OH-D3) were compared. The degree of obesity of the patients with higher BMD was significantly larger than that with lower BMD (p less than 0.005).

Aged↗
PubMed1991

Total and regional bone mineral content in patients with non-insulin dependent diabetes mellitus.

Total body bone mineral content and bone mineral content in various body sites were measured by dual-photon absorptiometry in 103 patients with non-insulin-dependent diabetes mellitus (NIDDM) and the findings were compared with those for 214 non-diabetic control subjects matched for age and body weight. Neither total body bone mineral content (TBBM) nor the bone mineral density of the third lumbar vertebra (L3 BMD) in the diabetic subjects differed from the values in control subjects of either sex, but the values were significantly decreased in patients diseased for at least five years when compared with control subjects. Regional bone mineral measurement showed prominent bone loss in the truncal site, but no reduction in bone mass was found in the head, pelvis, arms, or legs in either male or female patients. These results suggest that reduced TBBM and L3 BMD are associated with duration of the disease and that a site-specific bone defect is present in NIDDM.

Adult↗
PubMed1991

Lipoprotein metabolism in normolipidemic obese women during very low calorie diet: changes in high density lipoprotein.

We examined changes in high density lipoprotein (HDL) metabolism during a very low calorie diet weight reduction program in 6 massively obese normolipidemic women. The diet protocol consisted of a 1st low calorie diet (LCD; 1440, 1280, and 880 kcal daily for 1 week, each, in succession), a 1st very low calorie diet (VLCD; 420 kcal daily for 4 weeks, using Optifast 70), intermission (880 kcal daily for 1 week), the 2nd VLCD (4 weeks) and the 2nd LCD (880 and 1280-1440 kcal daily for 1 week, each). Mean body weight reduction was 18.9 kg. HDL-cholesterol, more specifically HDL2-cholesterol, reduced transiently during the 1st VLCD, intermission, and 2nd VLCD periods, and tended to increase in the 2nd LCD. Apolipoprotein (apo) A-I showed a similar change to HDL-cholesterol. However, apo A-II decreased persistently throughout the weight reduction program, and the apo A-I/apo A-II ratio increased significantly in the later part of the program. Serum triglyceride, apo B, and lipoprotein lipase (LPL) activity in post-heparin plasma did not change. These data suggest that the observed decrease in HDL-cholesterol was not due to a reduction in very low density lipoprotein-derived HDL production or to an LPL deficiency, but was consistent with reduction in chylomicron-derived HDL formation following dietary fat restriction.

Adult↗
PubMed1991

Obesity as a determinant of regional bone mineral density.

Total body and regional bone mineral density (BMD) and bone mineral content (BMC) in obese patients and healthy controls were assessed by dual-photon absorptiometry (DPA) in this study. In both men and women, BMD values in total body, pelvis, upper and lower extremities were significantly (p less than 0.05) higher in the obese group (body mass index greater than 28) than in the non-obese group (body mass index less than 23). These BMD values correlated significantly with body weights and with percentages of body fat. In the obese group, 8 massively obese women were treated with an 8-week very low calorie diet (VLCD), resulting in a 13.4 kg of mean body weight reduction. Although BMC in total body and in pelvis were maintained, significant decreases of BMC in the upper (from 275 +/- 30 to 255 +/- 26 g) and lower (from 871 +/- 47 to 805 +/- 31 g) extremities were observed following the 8-week VLCD treatment. These results suggest that body fat mass affects BMD and BMC preferentially in weight bearing bone, the changes of which are not always associated with changes in total body BMD or BMC.

Adult↗
PubMed1991

[Acute megakaryoblastic leukemia developing 11 years after diagnosis of essential thrombocythemia].

A 57-year-old man was diagnosed to have essential thrombocythemia (ET) in July 1977. He was doing well with continual medication of carboquone but was hospitalized because of slight unconsciousness and gait disturbance in May, 1988. His laboratory data were as follows: WBC count 81,600/microliters with 55% of blasts with cytoplasmic blebs, Hb 10.2 g/dl, and platelet count 2.6 x 10(4)/microliters. Bone marrow aspiration revealed hypercellular marrow with 72.8% blasts. Chromosomal analysis showed tetraploidy with 7p+ and 19p+. Cytochemistry of blasts showed the positivity for platelet peroxidase and CDw 41. The diagnosis of acute megakaryoblastic leukemia was made. Meningeal leukemia was also suspected by the cerebrospinal fluid data, and cytarabine was intrathecally injected. Then the percent of blasts of peripheral blood gradually decreased and the data of cerebrospinal fluid improved. However, several days later the patient became comatose probably due to cerebral bleeding, and died. In this case, two possibilities were considered (1) that a blastic transformation to acute leukemia from ET, and (2) that a secondary leukemia developed as a result of the chemotherapy, independently of ET. Since there was no evidence of myelodysplastic syndrome, it was concluded that this case represented a blastic transformation of ET.

Blast Crisis↗
PubMed1990

Neuronal modulation of calcium channel activity in cultured rat astrocytes.

The patch-clamp technique was used to study whether cocultivation of neurons and astrocytes modulates the expression of calcium channel activity in astrocytes. Whole-cell patch-clamp recordings from rat brain astrocytes cocultured with rat embryonic neurons revealed two types of voltage-dependent inward currents carried by Ca2+ and blocked by either Cd2+ or Co2+ that otherwise were not detected in purified astrocytes. This expression of calcium channel activity in astrocytes was neuron dependent and was not observed when astrocytes were cocultured with purified oligodendrocytes.

Animals↗
PubMed1990

Membrane depolarization and intracellular Ca2+ increase caused by high external Ca2+ in a rat calcitonin-secreting cell line.

1. Calcitonin secretion is regulated by the external Ca2+ concentration ([Ca2+]o) via a rise in intracellular Ca2+ concentration ([Ca2+]i). The mechanism which couples an increase in [Ca2+]o to an increase in [Ca2+]i was explored in a rat calcitonin-secreting cell line (rMTC 44-2). [Ca2+]i was monitored using Fura-2 AM, and the membrane potential or current was simultaneously measured. 2. Using the conventional whole-cell clamp, tetrodotoxin-sensitive voltage-gated Na+ channels, T- and L-type Ca2+ channels, and three types of K+ channels, the delayed K+ channel, the A-channel and the inward-rectifying channel were observed. 3. Using the nystatin-perforated whole-cell-clamp technique, the resting potential measured under current clamp in standard extracellular medium was -59.0 +/- 5.0 mV (mean +/- S.D., n = 25), and the input resistance was 3.9 +/- 1.9 G omega (n = 10). In 0.5 mM [Ca2+]o most cells (22/25) showed spontaneous action potentials. 4. An increase in [Ca2+]o depolarized the cell membrane and elevated [Ca2+]i even in the presence of 10 microM-tetrodotoxin. The rise in [Ca2+]i was greatly reduced when action potentials were inhibited by applying hyperpolarizing current. The increase in [Ca2+]i saturated with 3-4 mM [Ca2+]o. In 3 mM [Ca2+]o, [Ca2+]i was 188.9 +/- 40.5% (n = 12) of that in 0.5 mM [Ca2+]o. 5. In high [Ca2+]o the duration of action potentials was prolonged, but the action potential frequency did not always increase. In some cases it even decreased in high [Ca2+]o. 6. Two types of action potential were observed in high [Ca2+]o, one with a shorter duration and the other with a longer duration. [Ca2+]i transiently increased in association with the long-duration action potentials. These long-duration action potentials were also accompanied by a larger after-hyperpolarization. 7. Under voltage clamp, high [Ca2+]o caused a membrane conductance increase to Na+ ions. 8. Even when the membrane potential was clamped at a level below the threshold for Ca2+ channel activation, high [Ca2+]o provoked an increase of [Ca2+]i which was composed of an initial transient increase followed by a sustained increase, indicating an involvement of mechanisms other than Ca2+ influx through voltage-gated channels. The sustained increase was more frequently observed than the initial transient increase. The amplitude of the sustained phase was dependent on [Ca2+]o, and in 5 mM [Ca2+]o it was 120.9 +/- 18.9% (103-194%) (n = 58) of that in 0.5 mM [Ca2+]o.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1990

[Philadelphia chromosome positive acute mixed lineage leukemia with bcr (M-BCR-1) rearrangement].

We report two cases of Philadelphia (Ph1) chromosome positive acute mixed lineage leukemia (AMLL) with breakpoint cluster region (bcr) (M-BCR-1) rearrangement. A 31 year-old-man (case 1) and a 42 year-old-woman (case 2) were admitted to our hospital for further evaluation of leucocytosis with atypical blasts. Each case was diagnosed as having bilineal type of AMLL because: (1) blasts in each case consisted of larger myeloid cells positive for myeloperoxidase and small lymphoid cells positive for PAS, and blasts in case 2 were positive for TdT; (2) blasts in case 1 expressed B lymphoid associated antigen; (3) Southern analysis in each case showed clonal rearrangements of both the immunoglobulin heavy chain and the T cell receptor beta gene. These two cases demonstrated the Ph1 chromosome and rearrangement of the bcr (M-BCR-1) gene, but none of splenomegaly, basophilia, and additional chromosome abnormalities were observed. In addition, after achieving remissions, they didn't revert to chronic phase of chronic myelogenous leukemia (CML) and showed normal neutrophil alkaline phosphatase scores, and the Ph1 chromosome disappeared completely in case 1 and coexisted with the normal chromosome in case 2. These findings suggest that diagnosis of both cases should not be CML blast crisis (BC) but Ph1 positive acute leukemia, and Ph1 positive AMLL may be a distinct clinical entity to be distinguished from CML-BC.

Adult↗