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Biomedical subjects

H Kodama

Publications and source records attributed to H Kodama.

At least 469 records · Page 26Linked to original sources

Generation of osteoclasts from isolated hematopoietic progenitor cells.

A variety of studies have shown that osteoclasts originate from bone marrow, but their exact progenitors and differentiation pathway remain unclear. The treatment of mice with a high dose of 5-fluorouracil (5-FU) results in an enrichment for primitive hematopoietic progenitors; using this procedure, we prepared a new class of murine hematopoietic colonies that had very high secondary plating efficiencies in vitro. When spleen cells from mice pretreated in vivo with 5-FU were cultured in the presence of methylcellulose medium containing recombinant interleukin-3 (rIL-3), small colonies consisting of blast cells with little sign of differentiation developed on day 7 of culture. We lifted these blast colonies, pooled them, and replated them as secondary methylcellulose cultures in the presence of rIL-3 and erythropoietin. Approximately 60% of the cells formed colonies comprising various combinations of neutrophils, macrophages, eosinophils, mast cells, megakaryocytes, and erythroblasts. We replated such blast cells into microtiter wells and cultured them in the presence of rIL-3 (100 U/mL) or recombinant granulocyte-macrophage colony stimulating factor (GM-CSF) (100 U/mL) plus 1.25(OH)2D3 (10(-7) mol/L). Multinucleated cells appeared from day 14 of culture and approximately 100 giant cells per well were scored on day 21 of culture. Parathyroid hormone (1 U/mL) also induced the multinucleated cell formation. May-Grunwald-Giemsa staining revealed the large cells containing many nuclei in their cytoplasm, which is characteristic of bone-resorbing cells or osteoclasts. These cells showed a tartrate-resistant acid phosphatase (TRAP) activity. Calcitonin caused a striking shape change in these cells and suppressed the formation of multinucleated cells. Moreover, electron microscopy shows that these cells were able to resorb fetal calvariae. In the presence of r granulocyte-colony stimulating factor, r macrophage-colony stimulating factor, or r interleukin-6 plus 1.25(OH)2D3, formation of TRAP-positive multinucleated cells was lower compared with the support of rIL-3 or rGM-CSF. Mature macrophages collected from colonies did not form the multinucleated cells as described above, even in the presence of rIL-3 and 1.25(OH)2D3. Moreover, to exclude the possibility that osteoclasts generated from non-blast cells, we performed a cloning experiment from one isolated blast cell and demonstrated that single cells differentiate into osteoclasts or macrophages in the presence of rIL-3 with or without 1.25(OH)2D3. This system will provide a useful model for further analysis of osteoclast formation in vitro.

Animals↗

[Effects of ceftriaxone on severe infectious complications in hematological disorders. Tohkai Research Group on Infections in Hematological Disorders].

Ceftriaxone (CTRX), a new long acting antibiotic in the 3rd generation cephem group, was administered intravenously once or twice a day in daily doses of 1-6 g for at least 3 days to 86 patients with severe infections complicating hematopoietic disorders. Underlying diseases were acute leukemia in 41 cases, chronic leukemia in 3 cases, malignant lymphoma in 19 cases, myeloma in 7 cases and others. Most patients (55 cases) suffered from sepsis or suspected sepsis. As for efficacy rates classified by underlying diseases, the treatment was effective in 61.0% of patients with acute leukemia. As for efficacy rates classified by infections, the treatment was effective in 60.0% of patients with sepsis. No side effects were noted except rash in 2 patients. Abnormal hepatic functions were recognized in 3 patients but were not attributed to the agent in any case. The results indicate that CTRX is a safe and useful antibiotic for the treatment of severe infections accompanied by hematopoietic disorders.

Bacterial Infections↗

[Descriptive epidemiology of urolithiasis].

In this paper, urolithiasis is remarked from the standpoint of descriptive epidemiology, which examines the frequency distribution of a given disease in a population in terms of time, place and personal characteristics with an aim of identifying risk factors or some clues to the etiology. Some descriptive epidemiological features of urolithiasis are summarized. Prevalence rate is around 4% (4-15% in males and 4-8% in females), and incidence rate varies from area to area: 53.2 per 100,000 population in 1975 in Japan, 364 in 1976 in Malaysia, and 540 in 1979 in West Germany. Prevalence and/or incidence rates have, in general, increased in the developed countries since World War II and in the developing countries as well, where upward trends are quite analogous to the trends observed in the nineteenth century in Europe. Recurrence rate, which is much higher in males than in females, ranges from 31% to 75%, depending on the follow-up periods. In the industrialized countries, upper urinary (renal and ureteral) stones account for more than 90% of total stones, which are ordinarily calcium complexes in composition. More common in the developing countries are lower urinary (bladder and urethral) stones, frequently composed of magnesium ammonium phosphate, which indicates a close association with urinary tract infections. Variations in frequency are evident by season and by region within a country. Age and sex differentials in urinary stone formers are substantial: more common in males 30-40 years old in the industrialized countries and in children under 10 years old in the developing countries. Racial differentials are also noted; blacks appear to suffer less frequently than whites. Stone formers experience more frequent episodes of stone formation in their family members, particularly father and brothers, than non-stone formers. These findings on racial differentials and family preponderance suggest the possible relevance of genetic factors in stone formation. Stone formers are more likely to be occupationally sedentary and socially affluent. This observation and differentials by age and sex suggest the probable relevance of lifestyle and environmental factors in stone formation. Epidemiological factors incriminated for stone formation will be discussed in a separate paper.

Age Factors↗

[Analytical epidemiology of urolithiasis].

In this paper, urolithiasis is reviewed from the standpoint of analytical epidemiology, which examines a statistical association between a given disease and a hypothesized factor with an aim of inferring its causality. Factors incriminated epidemiologically for stone formation include age, sex, occupation, social class (level of affluence), season of the year and climate, dietary and fluid intake and genetic prodisposition. Since some of these factors are interlinked, they are broadly classified into five categories and epidemiologically looked over here. Genetic predisposition is essentially endorsed by the more frequent episodes of stone formation in the family members of stone formers, as compared to non-stone formers. Nevertheless, some environmental factors (likely to be dietary habits) shared by family members are believed to be relatively more important than genetic predisposition. A hot, sunny climate may influence stone formation through inducing dehydration with increased perspiration and increased solute concentration with decreased urine volume, coupled with inadequate liquid intake, and possibly through the greater exposure to ultraviolet radiation which eventually results in an increased vitamin D production, conceivably correlated with seasonal variation in calcium and oxalate excretion to the urine. Urinary tract infections are importantly involved in the formation of magnesium ammonium phosphate stones in particular. The association with regional water hardness is still in controversy. Excessive intake of coffee, tea and alcoholic beverages seemingly increase the risk of renal calculi, though not consistently confirmed. Many dietary elements have been suggested by numerous clinical and experimental investigations, but a few elements are substantiated by analytical epidemiological investigations. An increased ingestion of animal protein and sugar and a decreased ingestion of dietary fiber and green-yellow vegetables are linked with the higher probability of stone formation in the industrialized countries. No trace elements in foodstuffs and liquids have been epidemiologically associated. The dietary guidelines for avoiding stone formation and/or recurrence are summarized in this paper, including other daily-life recommendations.

Diet↗

[Experimental study of normal liver regeneration in hepatic arterial infusion with degradable starch microspheres (DSM)].

Influence of hepatic arterial infusion with degradable starch microspheres (DSM) or with anti-cancer drug or with both for normal liver regeneration in rat was determined by histological and microautoradiographical examination and liquid scintilation before or after 70% hepatectomy. DSM was seen in interlobular artery in early phase after hepatic arterial infusion, but disappeared into the central vein by degrees for 2 hours later. Adriamycin (ADM) in serum was detected for a long time after hepatic arterial infusion with DSM + ADM. In the heart muscle, a significantly lower concentration of ADM was seen in the DSM + ADM group than in the ADM only group. In the case of hepatic arterial infusion with DSM only after hepatectomy, there was no influence on normal liver regeneration. No significant difference was seen between hepatic arterial infusion and intravenous infusion with ADM only. However, in the case of hepatic arterial infusion with DSM + ADM after hepatectomy, a significant difference was seen in the inhibition of liver regeneration from any other groups.

Animals↗

[The therapeutic effects of OK-432 combined adoptive immunotherapy (AIT) against liver metastases of breast cancer].

We studied the effect of OK-432 combined AIT in 24 cases of liver metastases of breast cancer. Eleven of the 16 patients (69%) who received intraarterial transfer responded to this therapy. On the other hand, no patients responded to intravenous or intraportal transfer. The minimum cell number for a therapeutic response was 10(9) cells. Four patients had abscopal effects after therapy. The serum CEA level paralleled the therapeutic effects. There were no severe side effects accompanying this therapy. These results indicate that intra-arterial OK-432 combined AIT should be the first choice therapy against liver metastases of breast cancer.

Biological Products↗

Isolation and identification of embryo-derived platelet-activating factor in mice.

We isolated a platelet-activating factor (PAF) derived from mouse embryos and identified it by bioassay utilizing washed rabbit platelets. We also tried further characterization of the factor by high-performance liquid chromatography (HPLC) and electron-impact mass spectrometry (EI-MS). 1. In the thin-layer chromatography (TLC) of the medium after a two day culture of 30 embryos at the two-cell stage, no obvious spot appeared at the site of 1-O-acetyl-2-O-alkyl-SN-glyceryl-3-phosphocholine (AGEPC). But a small, pale spot appeared at the site of lyso-AGEPC. 2. A remarkable aggregation activity was present at the site of the Rf and appearance time that was almost the same as for AGEPC in both TLC and HPLC. However, detection of the substance by UV absorption (203nm) in HPLC was unsuccessful. 3. The PAF activity shown in the culture medium was suspected to be 10(-10 - 10(-11) M/embryo and it was not inhibited by pretreatment with indomethacin and ADP scavenger. 4. Embryo-derived PAF had an HPLC appearance time 1-2 min. longer than that of synthetic AGEPC (C16). EI mass spectrum of embryo-derived PAF was partly inconsistent with that of synthetic AGEPC (C16). These results confirm the evidence of PAF release from mouse embryos and show the possibility that a far greater amount of its lyso-derivative is present in the culture medium. Embryo-derived PAF is presumed to be AGEPC or a substance resembling AGEPC in its chemical structure and some structural difference may exist between embryo-derived PAF and synthetic AGEPC (C16).

Animals↗

Dimerization of neurokinin A and B COOH-terminal heptapeptide fragments enhanced the selectivity for tachykinin receptor subtypes.

We have synthesized dimeric analogues of neurokinin A and B COOH-terminal heptapeptide fragments and evaluated their biological activities to contract isolated smooth muscle preparations of the guinea-pig ileum and rat vas deferens. The dimers were fairly active and showed two-fold increased selectivity for receptors in the guinea-pig ileum as compared with monomers. Extremely slow dissociation indicated a possible bivalent interaction between dimer and receptor.

Amino Acid Sequence↗

B lymphopoiesis on stromal cell clone: stromal cell clones acting on different stages of B cell differentiation.

B lymphopoiesis supporting activities of two stromal cell clones, MC3T3-G2/PA6 (PA6) and ST2, were compared. When normal bone marrow cells were cultured in these clones under Whitlock-Witte-type condition, mature B cells were generated only in the culture with the ST2 layer. The cells maintained on the PA6 layer, however, contained the precursor cells giving rise to mature B cells when transferred to the ST2 layer. Thus, PA6 is a stromal cell clone capable of supporting the early B progenitors but cannot support a further maturation step into pre-B cells. The immunoglobulin heavy chain gene configuration of B progenitors maintained on the PA6 layer diversified after their transfer onto ST2 layer. This suggests that they are actually the earliest progenitors. This marked difference in the stromal cell activities between PA6 and ST2 could also be distinguished by stromal cell-dependent pre-B cell lines. Among four ST2-dependent pre-B cell lines tested, two grew only on the ST2 layer, which is capable of supporting B lymphopoiesis, while the others grew both on the ST2 and PA6 layers. These results strongly suggest that the process of intra-marrow B cell development is controlled by more than one signal acting on different stages of B cell differentiation.

Animals↗

Persistence of foam cells in rabbit xanthoma after normalization of serum cholesterol level.

Xanthoma was produced in diet-induced hypercholesterolemic rabbits by intradermal dextran sulfate injections. The serum cholesterol level returned to the normal range at about 10 weeks after ending the cholesterol diet. Gross observations after cessation of the cholesterol diet revealed a decrease in xanthomatous infiltrations. However, the dense foam cell infiltrations and cholesterol accumulations showed no signs of regression at even 9 months after ending the cholesterol diet. Signs of foam cell migration into the blood stream were not observed. The persistence of the xanthoma may be due to a lack of acceptors, such as high-density lipoproteins, that remove the cholesterol from the foam cells. During our 9-month observation period, some foam cells were degenerated and a few were fused with each other to transform into Touton-type giant cells. Nonfoamy histiocytes were infiltrated around these degenerating foam cells. The histiocytes may have transformed into foam cells by incorporating the lipids of the degenerated foam cells.

Animals↗

Biochemical studies on prolidase in sera from control, patients with prolidase deficiency and their mother.

Prolidase activity in serum from normal subjects and the mother of two patients was readily detected without adding Mn2+ to the assay, and the activity was increased by addition of Mn2+ to the assay or preincubation with Mn2+. However, the activity in serum from patients with prolidase deficiency against gly-pro, leu-pro and val-pro could not be detected irrespective of Mn2+ conditions and activity against met-pro, ala-pro and phe-pro also showed a marked reduction compared to controls. Both normal and the patients' mother's prolidase activity against gly-pro was reduced about 20% at 60 degrees C compared to the activity at 37 degrees C, but the addition of Mn2+ at 55 degrees C increased the activity about 1.8-fold, whereas prolidase activity of patients could not be increased by the addition of Mn2+. The addition of Co2+ increased prolidase activity in serum from control and the patients' mother but did not increase the heat stability. These results indicate that prolidase in serum from patients with prolidase deficiency is altered rather than markedly reduced in amount.

Dipeptidases↗

Microcarriers facilitate mineralization in MC3T3-E1 cells.

MC3T3-E1 cells showed mineral deposits after about 1 week of culture when incubated in the presence of microcarrier beads. These deposits appeared as white spots on the dish surface, and under light microscopy the cells showed multiple cell layers and mineralization around the microcarriers. The deposits stained positive with calcium-specific Von Kossa's method. Using conventional assay, alkaline phosphatase activity (ALP) and parathyroid hormone-stimulated intracellular cAMP production were lower in the microcarrier cultures than in the control, but using cytochemical methods, high alkaline phosphatase activity was found around the microcarriers. These results indicate that microcarriers facilitated the formation of multiple cell layers and provided a culture environment for mineralization.

Alkaline Phosphatase↗

Biorhythm of core temperature in depressive and non-depressive alcoholics.

Core temperature was longitudinally evaluated during the day- and nighttime in six non-depressive and in four depressive alcoholics who had been abstaining from alcoholic beverages. The least squares spectrum method was employed for detecting the periods and acrophase of the circadian rhythm of core temperature. Although normal periods were observed in all the patients throughout the study, an abnormal acrophase was found in many patients, especially in depressive alcoholics. On the 3rd and 4th days after alcohol withdrawal, all of the four depressive alcoholics showed a phase advance of the circadian rhythm, and three patients of the six non-depressive alcoholics exhibited an abnormal acrophase. On the 21st and 22nd days after alcohol withdrawal, a normal acrophase was observed in two patients of the four depressives and in four of the six non-depressives. The mean core temperature was higher in the depressives than in the non-depressives on the third and fourth days after alcohol withdrawal.

Adult↗

Elevation of bone conduction threshold in children with middle ear effusion.

A retrospective study of children having otitis media with effusion revealed fluctuations in bone conduction thresholds as well as in air conduction thresholds. Previous investigations in this area presented both low- and high-tone bone conduction hearing loss which were reversible. We conducted a detailed study including complete otologic, audiologic and tympanometric evaluation of 27 (41 ears) children who had fluctuating bone conduction hearing loss. From these audiologic examinations, 3 types of bone conduction hearing loss could be classified: high-tone, low-tone and flat-type bone conduction hearing loss. We observed the shift of bone conduction thresholds in children after removal of middle-ear fluids by the appropriate medical management.

Audiometry↗