Biomedical subjects

T Tajima

Publications and source records attributed to T Tajima.

At least 109 records · Page 6Linked to original sources

PubMed1999

Inflammatory cytokine production and specific antibody responses to lipopolysaccharide from endodontopathic black-pigmented bacteria in patients with multilesional periapical periodontitis.

We examined the induction of the cytokines interleukin (IL)-1 beta, IL-6, and IL-8 by lipopolysaccharides (LPSs) from several species of possible endodontopathic black-pigmented bacteria. Studies were conducted in human whole blood cultures from six patients (two from each group) with differing numbers of periapical periodontitis lesions (i.e. patients with radiographically clear periapical lesions in 10 or more teeth (high-lesion group, n = 4), in one or two teeth (low-lesion group, n = 6), and six healthy volunteers with no periapical lesions (no lesion group)). LPS from Prevotella intermedia ATCC 25611, Porphyromonas gingivalis 381, and Prophyromonas endodontalis ATCC 27067 induced a higher IL-8 response in the subjects of the high-lesion group, compared with the subjects of the other two groups. To ascertain the degree of sensitization by test bacteria, we examined the reactivities of antibodies in serum and saliva from the subjects to different bacterial species. LPS from P. gingivalis reacted strongly with sera from the high-lesion group. Thus, LPS from black-pigmented bacteria may be involved in multilesional periapical periodontitis by inducing particular cytokines and/or humoral immune responses.

Adult↗

PubMed1999

Dose escalation and pharmacokinetic study of a humanized anti-HER2 monoclonal antibody in patients with HER2/neu-overexpressing metastatic breast cancer.

We conducted a phase I pharmacokinetic dose escalation study of a recombinant humanized anti-p185HER2 monoclonal antibody (MKC-454) in 18 patients with metastatic breast cancer refractory to chemotherapy. Three or six patients at each dose level received 1, 2, 4 and 8 mg kg(-1) of MKC-454 as 90-min intravenous infusions. The first dose was followed in 3 weeks by nine weekly doses. Target trough serum concentration has been set at 10 microg ml(-1) based on in vitro observations. The mean value of minimum trough serum concentrations at each dose level were 3.58 +/- 0.63, 6.53 +/- 5.26, 40.2 +/- 7.12 and 87.9 +/- 23.5 microg ml(-1) respectively. At 2 mg kg(-1), although minimum trough serum concentrations were lower than the target trough concentration with a wide range of variation, trough concentrations increased and exceeded the target concentration, as administrations were repeated weekly. Finally 2 mg kg(-1) was considered to be sufficient to achieve the target trough concentration by the weekly dosing regimen. One patient receiving 1 mg kg(-1) had grade 3 fever, one at the 1 mg kg(-1) level had severe fatigue defined as grade 3, and one at 8 mg kg(-1) had severe bone pain of grade 3. No antibodies against MKC-454 were detected in any patients. Objective tumour responses were observed in two patients; one receiving 4 mg kg(-1) had a partial response in lung metastases and the other receiving 8 mg kg(-1) had a complete response in soft tissue metastases. These results indicate that MKC-454 is well tolerated and effective in patients with refractory metastatic breast cancers overexpressing the HER2 proto-oncogene. Further evaluation of this agent with 2-4 mg kg(-1) weekly intravenous infusion is warranted.

Antibodies, Monoclonal↗

PubMed1999

Restoration of adrenal steroidogenesis by adenovirus-mediated transfer of human cytochromeP450 21-hydroxylase into the adrenal gland of21-hydroxylase-deficient mice.

21-Hydroxylase deficiency, a potentially fatal disease due to deletions or mutations of the cytochrome P450 21-hydroxylase gene (CYP21), causes congenital adrenal hyperplasia (CAH) with low or absent glucocorticoid and mineralocorticoid production. The feasibility of gene therapy for CAH was studied using 21OH-deficient mice (21OH-) and a replication-deficient adenovirus containing the genomic sequence of human CYP21 (hAdCYP21). Intra-adrenal injection of hAdCYP21 in 21OH- mice induced hCYP21 mRNA with the highest expression from 2 to 7 days before a gradual decline. 21OH activity measured in adrenal tissue increased from undetectable to levels found in wild-type mice 2 to 7 days after AdhCYP21 injection. Adrenal morphology of 21OH- mice showed lack of zonation, and hypertrophy and hyperplasia of adrenocortical mitochondria with few tubulovesicular christae. These morphological abnormalities were markedly improved 7 days after hAdCYP21 gene therapy. Plasma corticosterone increased from undetectable levels to values similar in wild-type mice by 7 and 14 days, declining over the next 40 days. This is the first demonstration that a single intra-adrenal injection of an adenoviral vector encoding CYP21 can compensate for the biochemical, endocrine and histological alterations in 21OH-deficient mice, and shows that gene therapy could be a feasible option for treatment of CAH.

Adenoviridae↗

PubMed1999

Both stump area and volume of distal sensory nerve segments influence the regeneration of sensory axons in rats.

We examined the influence of both stump area and volume of a distal sensory nerve segment on neurotropic induction of regenerating sensory axons in a rat saphenous nerve model. In group 1 (n = 10) the proximal stump of the severed saphenous nerve was inserted into the proximal channel, and a 2 cm free nerve segment and a double-barrelled 1 cm free nerve segment were inserted into the distal two channels of a silicone Y-chamber. In group 2 (n = 10), 2 cm and 1 cm free nerve segments were inserted into the distal two channels of a Y-chamber. The gap between the stumps was set at 4 mm. After six weeks, we counted and compared the number of regenerated myelinated sensory axons in the distal two channels. Significantly more axons regenerated in the wider stump area channel of group 1 and in the larger volume channel of group 2 than in the opposite channel in either group (p < 0.05 in each case).

Animals↗

PubMed1999

A dose-finding study of lenograstim (glycosylated rHuG-CSF) for peripheral blood stem cell mobilization during postoperative adjuvant chemotherapy in patients with breast cancer. Lenograstim/Breast Cancer Study Group.

BACKGROUND: The optimum dose of granulocyte colony-stimulating factor (G-CSF) for peripheral blood stem cell (PBSC) mobilization after disease-oriented, conventional-dose chemotherapy remains unknown. METHODS: A multicenter dose-finding study of glycosylated G-CSF (lenograstim) for the mobilization of PBSCs following adjuvant CAF chemotherapy (cyclophosphamide, doxorubicin and 5-fluorouracil) was performed in 38 patients with postoperative breast cancer. Each 10, ten and eight patients were sequentially allocated to one of the three dose groups (2, 5 and 10 micrograms/kg, respectively) of lenograstim. Lenograstim was administered subcutaneously (s.c.) daily from day 8 to the day of the last apheresis and CD34+ cells and colony-forming units-granulocyte macrophage (CFU-GMs) in peripheral blood were measured serially. Additionally, 10 patients who received adjuvant CAF chemotherapy alone also participated in the study, as a control. RESULTS: Lenograstim was well tolerated up to 10 micrograms/kg, except for one patient given 10 micrograms/kg who developed transient grade 3 hepatic enzyme elevation. The peak levels of CD34+ cells and CFU-GMs in peripheral blood showed dose-response relationships. The median peak CD34+ cells for the 0, 2, 5 and 10 micrograms/kg dose groups were 5.4, 34.3, 55.0 and 127.6 cells/microliter, respectively, and those of CFU-GMs for the 0, 2, 5 and 10 micrograms/kg dose groups were 0.01, 0.33, 1.32 and 3.30 CFU-GMs/microliter, respectively. CONCLUSIONS: Considering the previous reports suggesting that a pre-apheresis number of 40-50 CD34+ cells/microliter in peripheral blood is highly predictive for achievement of more than 2.5 x 10(6) CD34+ cells/kg in a standard apheresis procedure of 10 litres, the optimum dose of lenograstim for PBSC mobilization following CAF chemotherapy in patients with postoperative breast cancer is 5 micrograms/kg/day s.c.

Adjuvants, Immunologic↗

PubMed1999

A small breast cancer detected by PET.

A small breast cancer was detected by positron emission tomography (PET) in an asymptomatic individual. Physical examination, mammography and magnetic resonance imaging all failed to identify the tumor. Treatment was partial resection of the breast. Based on the resected specimen, the tumor was 6 mm in diameter. Although previous studies have shown PET to be highly sensitive for the detection of primary breast cancer, detectability of tumors smaller than 1 cm is uncertain. Our case suggests the potential utility of PET for the early detection of primary breast cancer.

Breast Neoplasms↗

PubMed1999

Purification and characterization of a novel isoform of myosinase from spear squid liver.

A novel isoform of myosinase was purified to homogeneity from liver of spear squid by sequential chromatographies using SP Sephadex, hydroxylapatite, Zn/Co chelating affinity, and TSK-gel G2000SW columns. Myosinase activity was detected as a single peak of 45-kDa protein by gel filtration. The novel isoform of myosinase specifically hydrolyzed a rabbit skeletal muscle myosin heavy chain into products of 120 and 100 kDa in the presence of Co(2+) ions, and the cleavage site in the myosin heavy chain was quite different from those of two known myosinase isoforms, I and II. Therefore, we named the novel isoform myosinase III. Myosinase III was also distinguishable from myosinase I by its amino-terminal sequence. The sequence showed similarity to an internal sequence of the astacin family.

Amino Acid Sequence↗

PubMed1999

Adrenomedullary function is severely impaired in 21-hydroxylase-deficient mice.

Deficiency of 21-hydroxylase (21-OH), one of the most common genetic defects in humans, causes low glucocorticoid and mineralocorticoid production by the adrenal cortex, but the effect of this disorder on the adrenomedullary system is unknown. Therefore, we analyzed the development, structure, and function of the adrenal medulla in 21-OH-deficient mice, an animal model resembling human congenital adrenal hyperplasia. Chromaffin cells of 21-OH-deficient mice exhibited ultrastructural features of neuronal transdifferentiation with reduced granules, increased rough endoplasmic reticulum and small neurite outgrowth. Migration of chromaffin cells in the adrenal to form a central medulla was impaired. Expression of phenylethanolamine-N-methyltransferase (PNMT) was reduced to 27 +/- 9% (P<0.05), as determined by quantitative TaqMan polymerase chain reaction, and there was a significant reduction of cells staining positive for PNMT in the adrenal medulla of the 21-OH-deficient mice. Adrenal contents of epinephrine were decreased to 30 +/- 2% (P<0. 01) whereas norepinephrine and dopamine levels were reduced to 57 +/- 4% (P<0.01) and 50 +/- 9% (P<0.05), respectively. 21-OH-deficient mice demonstrate severe adrenomedullary dysfunction, with alterations in chromaffin cell migration, development, structure, and catecholamine synthesis. This hitherto unrecognized mechanism may contribute to the frequent clinical, mental, and therapeutic problems encountered in humans with this genetic disease.

Adrenal Hyperplasia, Congenital↗

PubMed1999

Direct spectroscopic observation of multiple-charged-ion acceleration by an intense femtosecond-pulse laser.

We have observed evidence of the emission of energetic He-and H-like ions of fluorine more than 1 MeV produced via the optical field ionization (OFI) from a solid target irradiated by an intense I=(2-4)x10(18) W/cm(2) (60 fs, lambda=800 nm), obliquely incident p-polarized pulse laser. The measured blue wing of He(alpha), He(beta), and Ly(alpha) lines of fluorine shows a feature of the Doppler-shifted spectrum due to the self-similar ion expansion dominated by superthermal electrons with the temperature T(h) approximately 100 keV. Using a collisional particle-in-cell simulation, which incorporates the nonlocal-thermodynamic-equilibrium ionization including OFI, we have obtained the plasma temperature, line shape, and maximal energy of accelerated ions, which agree well with those determined from the experimental spectra. The red wing of ion spectra gives the temperature of bulk plasma electrons.

Journal Article↗

PubMed1999

Stationary periodic and solitary waves induced by a strong short laser pulse.

The propagation of a relatively intense short laser pulse into an isotropic plasma is described. A kinetic equation for the spectral function of the electromagnetic waves is derived for an arbitrary amplitude pump wave, where the fully relativistic case is considered. The resulting kinetic equation of the spectral function is used along with the set of equations of the plasma to derive a general dispersion relation, where relativistic effects play an important role. In the case of a super-strong short laser pulse, Langmuir waves, with phase velocities larger than the speed of light, and waves of ion-sound type, which are damped only on ions, are found. In addition, for the case when the plasma density along with the mass of the electrons satisfies the "frozen-in" condition, stationary nonlinear new type of ion-sound waves are investigated. The mechanism of the emission of these waves is also discussed.

Journal Article↗

PubMed1999

A surgical treatment of infected pancreatic necrosis: retroperitoneal laparotomy.

BACKGROUND/AIMS: Due to the anatomical location of the pancreas, sufficient drainage of a pancreatic necrosis by laparotomy may be unsatisfactory. METHODS: CT and helical CT have provided extremely useful information on the surgical treatment of necrotic pancreatitis. The retroperitoneal approach (RPA) allows direct and complete removal of necrotic tissues. RESULTS: RPA was used to treat 8 patients with infected pancreatic necrosis. Excision of necrotic tissues was effective and could minimize the complications often associated with laparotomy such as bleeding and intestinal injuries. CONCLUSION: By CT and helical CT, three-dimensional images of pancreatic necrosis are obtained. These investigations have greatly facilitated RPA, which has advantages over laparotomy in the treatment of infected pancreatic necrosis.

Adult↗

PubMed1999

Near-normal linear growth in the setting of markedly reduced growth hormone and IGF-1. A case report.

A 14.2-year-old prepubertal boy diagnosed with complete-type growth hormone deficiency and tertiary hypothyroidism, keeps growing in the height range between -1 and -2 SD. He has been treated with levothyroxine only. To understand the growth mechanism of this boy, we analyzed the serum growth hormone (GH) with a radioimmunoassay (RIA), serum GH bioactivity with Nb2 and erythroid progenitor cell bioassays, and growth hormone-binding protein (GHBP) with a ligand-mediated immunofunctional assay (LIFA). In addition, IGF-1 and free IGF-1 were analyzed by immunoradiometric assay (IRMA) and insulin-like growth factor-binding protein-3 (IGFBP-3) by Western immunoblot. Peak GH-RIA responses to insulin, arginine and GH-releasing factor, and nocturnal GH secretion, were low (0.5-2.3 ng/ml); bioactive GH was low (0.313 ng/ml), and GHBP was elevated (84 ng/ml). The serum levels of IGF-1 and free IGF-1 were continuously low, 17.1-39.3 and 0.17-0.26 ng/ml, respectively. Moreover, serum IGFBP-3 levels were low (1.68- 1.39 mg/l) and IGFBP-3 protease activity was negative. Prolactin and insulin were in the normal range. The result of the assay for growth-promoting activity showed that the patient's serum stimulated normal erythroid progenitor cells twice as potently as did healthy thin adult control serum. These results suggest that GH and IGF-1 are not indispensable for maintaining physical growth in this boy. Thus, it appears that circulating GH and IGF-1 are not mandatory requirements for maintaining normal physical growth, and other, as yet uncharacterized, pathways or growth factors might be sufficiently compensatory under certain conditions.

Adolescent↗

PubMed1999

Prenatal dexamethasone treatment does not prevent alterations of the hypothalamic pituitary adrenal axis in steroid 21-hydroxylase deficient mice.

A major difficulty in the clinical management of congenital adrenal hyperplasia (CAH) is adjustment of glucocorticoid doses to suppress ACTH and androgens without causing iatrogenic hypercortisolism. The possibility that structural alterations of the adrenal or a dysfunction of the hypothalamic pituitary adrenal (HPA) axis caused by glucocorticoid deficiency during fetal life contribute to this problem was studied in 21-hydroxylase deficient mice caused by deletion of the cytochrome P-450 21-hydroxylase gene. Homozygotes showed about 200-fold elevations in plasma progesterone, hyperplastic adrenal cortices lacking zonation, and structural alterations of adrenocortical mitochondria. Histochemical studies showed increases in hypothalamic CRH messenger RNA (mRNA) and immunoreactive (ir) CRH, and pituitary POMC mRNA in homozygous mice. VP mRNA levels in PVN perikarya were normal, but irVP in parvicellular terminals of the median eminence was increased in homozygotes. Prenatal dexamethasone treatment (0.5 to 2 microg/day) prevented the increases in CRH mRNA, whereas dexamethasone only partially decreased POMC mRNA levels, and had no effect on serum progesterone levels. The data suggest that intrauterine glucocorticoid deficiency in CAH causes hyperactivity of the hypothalamic-pituitary-corticotroph axis and insensitivity to glucocorticoid feedback. These studies in 21-hydroxylase deficient mice may provide new insights on the mechanism, clinical manifestations and management of some types of human CAH.

Adrenal Glands↗

PubMed1999

Analysis of porcine cytomegalovirus DNA polymerase by consensus primer PCR.

We used a consensus primer PCR method to amplify a region of herpesviral DNA-directed DNA polymerase gene using degenerate primers for initial characterization of the porcine cytomegalovirus (PCMV) genome. The sequence of the PCR product from PCMV DNA template and its alignment with other herpesvirus DNA polymerase counterparts showed that both conserved amino acid residues and conservative amino acid substitutions are in parallel. Phylogenetic analysis revealed that PCMV should be included in the clade comprising human herpesvirus 6 and 7, rather than human and mouse cytomegaloviruses, in Betaherpesvirus subfamily.

Amino Acid Sequence↗

PubMed1999

Neutralizing feature of commercially available feline calicivirus (FCV) vaccine immune sera against FCV field isolates.

Four types of commercially available feline calicivirus (FCV) vaccine were compared in terms of their efficacy on the basis of the ability of the sera of specific-pathogen-free cats immunized by two injections of each type of vaccine to neutralize FCV field isolates. Each vaccine immune serum neutralized relatively well strains F4, F9, and 255, which were FCV laboratory strains. As to 36 strains of field isolates, however, vaccines A, B, C, and D immune sera did not neutralize 18-20 of the strains (50.0%-55.6%), 19-22 of the strains (52.8%-61.1%), 22-25 of the strains (61.1%-69.4%), and 8-16 of the strains (22.2%-44.4%), respectively. These results indicate that there is much difference in neutralizing antigenicity between the existing vaccine strains and the FCV strains that are prevalent in Japan, suggesting the need for improvement of FCV vaccines.

Animals↗

PubMed1999

Sandwich enzyme-linked immunosorbent assay by using monoclonal antibody for detection of Clostridium perfringens enterotoxin.

Sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative estimation of Clostridium perfringens enterotoxin (CPE) with monoclonal and polyclonal antibodies as capturing and detecting antibodies, respectively. The dose-dependent relationship between absorbance at 405 nm and concentration of purified CPE was obtained over the range of 0.64-400 ng/ml. The sandwich ELISA was fond to detect crude CPE in culture and CPE in 10% fecal extracts. This method is convenient, rapid and sensitive for specific detection of CPE.

Animals↗

PubMed1999

21-Hydroxylase deficiency presenting as massive bilateral adrenal masses in the seventh decade of life.

A 72-year-old woman was found to have massive bilateral adrenal masses on computed tomography and was diagnosed with 21-hydroxylase deficiency (21-OHD) based on endocrinological findings. Physical examination revealed no abnormalities except markedly short stature. She was diagnosed with 21-OHD because she had an elevated serum 17alpha-hydroxyprogesterone (17-OHP) level which significantly decreased in response to dexamethasone. Percutaneous CT-guided biopsy and later autopsy confirmed that the adrenal masses were due to adrenocortical hyperplasia. Analysis of the CYP21 gene revealed that the patient was a compound heterozygote for the Ile-172-->Asn mutation in exon 4 and the 8-bp deletion in exon 3. Simple virilizing 21-OHD (SV) would be predicted from this genotype. She had few symptoms associated with 21-OHD except for markedly short stature, but the serum 17-OHP level was higher than that of typical nonclassical form of 21-OHD and near to that of typical SV. This finding was confirmed by analysis of the CYP21 gene. From these results, we report that when adrenal masses are incidentally detected, 21-OHD should be ruled out to avoid excessive examination and surgery on the suspicion of adrenal carcinoma.

Adrenal Cortex↗

PubMed1999

Pseudolesions of the liver possibly caused by focal rib compression: analysis based on hemodynamic change.

OBJECTIVE: The purpose of this study is to show and analyze the CT appearance of pseudolesions of the liver caused by rib compression and to discuss the possible mechanism on the basis of findings of incremental dynamic CT, CT during arterial portography, and CT hepatic arteriography. CONCLUSION: Focal compression of the liver caused by curved ribs can cause transient focal diminishment of portal venous perfusion without significantly altering hepatic arterial perfusion. Such diminishment may be observed as low-density areas on the early phase of incremental dynamic CT.

Aged↗