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Biomedical subjects

K Dan

Publications and source records attributed to K Dan.

At least 37 records · Page 2Linked to original sources
PubMed2000

Computer-assisted infrared thermographic study of axon reflex induced by intradermal melittin.

The aim of the present study was to investigate whether melittin, the principal toxin of the honeybee (Apis mellifera) venom, can be used as an algogenic agent in the study of pain in humans. Five micrograms of melittin in 0.5 ml of saline was intradermally injected into the volar aspect of the forearm. Resultant pain was scored by a visual analogue scale (VAS), and skin temperature change was analyzed by means of a computer-assisted infrared thermography. Intradermal melittin temporarily produced severe pain, followed by a sustained increase in skin temperature. The skin temperature increase peaked in about 10 min and outlasted 1 h. Topical application of 10% lidocaine gel did not significantly suppress the melittin-induced pain, but markedly suppressed both the increase in the peak temperature and the area of temperature increase. In conclusion, 5 microg of melittin is sufficient to produce pain in humans and 10% lidocaine gel differentially decreases the melittin-induced axon reflex without any significant analgesic effect.

Administration, Topical↗
PubMed2000

T cell immune responses against melanoma and melanocytes in cancer and autoimmunity.

T cell responses specific for melanoma cells and melanocytes appear to be involved in the rejection of melanoma tumors, as well as in the development of autoimmune reactions in patients with Vogt-Koyanagi-Harada disease (VKH), sympathetic ophthalmia, or autoimmune vitiligo. Some of the target antigens for those T cells have been isolated using cDNA expression cloning with melanoma reactive T cells derived from lymphocytes tumor infiltrating (TIL) of patients with melanoma. These include melanocyte specific proteins, such as tyrosinase, TRP1, TRP2, gp100, and MART-1, cancer-testis antigens, and mutated peptides derived from genetic alterations in melanoma cells. Some of the melanoma reactive T cells appear to respond to cryptic or subdominant self epitopes in melanosomal proteins. Modification of those epitopes to increase their immunogenicity by replacement of amino acids at primary anchor residues for peptide/MHC binding, allowed an improvement in immunotherapy for patients with melanoma. Targets for autoreactive T cells against melanocytes in those autoimmune disorders remain to be identified. Isolation of novel target antigens is important for understanding these pathological T cell responses, as well as for developing new diagnostic and treatment methods for these diseases. A variety of techniques, including cDNA expression cloning with T cells, serological analysis of recombinant cDNA expression libraries (SEREX), cDNA subtraction with representational differential analysis (RDA), and serial analysis of gene expression (SAGE) are now being applied to identify novel melanoma/melanocyte antigens recognized by T cells and antibodies.

Autoimmunity↗
PubMed2000

Flow cytometric assessment of CD15+CD117+ cells for the detection of minimal residual disease in adult acute myeloid leukaemia.

There is little information available regarding immunophenotypic monitoring of minimal residual disease (MRD) in acute myeloid leukaemia (AML). We investigated leukaemic cells co-expressing CD15 and CD117 (CD15+CD117+) in 72 adult AML cases at diagnosis. In 22 cases (31%) with various AML subtypes, more than 5% of leukaemic cells showed the CD15+CD117+ phenotype (range 5.22-55.48%). These 22 cases were younger and had a higher complete remission (CR) rate than the other AML cases, but the CD15+CD117+ cell percentage at diagnosis showed no correlation with the CR duration among the 72 cases. The CD15+CD117+ cell percentage showed a range of 0.00-0.08% in bone marrow cells from 10 haematologically normal subjects. We also investigated CD15+CD117+ cells in sequential bone marrow samples from 17 AML patients who achieved CR and who had had more than 5% CD15+CD117+ leukaemic cells at diagnosis. Because the CD15+CD117+ cell percentage varied among these AML cases, we calculated the percentage of MRD ¿MRD% = [CD15+CD117+ cells (%) in each sequential marrow sample] / [CD15+CD117+ cells (%) at diagnosis of the corresponding case] x 100¿. A high MRD% after 10 months of CR was significantly associated with a short CR duration (P = 0.0004), whereas continuation of a well-reduced MRD% was associated with a long CR duration. The leukaemic cells conserved the CD15+CD117+ phenotype in all of the eight cases who relapsed. Flow cytometric monitoring of CD15+CD117+ cells is simple and can be applied to a substantial fraction of AML cases. This monitoring may be useful for predicting relapse of adult AML.

Adult↗
PubMed2000

Adenosine potentiation of neuromuscular blocking agents in guinea-pigs.

We have investigated the effects of adenosine i.v. on neuromuscular block induced by rocuronium, vecuronium and pipecuronium in an in vivo guinea-pig sciatic nerve-tibialis anterior preparation. The ED50 of each neuromuscular blocker was determined from cumulative log dose-response regression lines (n = 14). In separate experiments, adenosine 0.1 mg kg-1 min-1 or the same volume of 0.9% NaCl was given i.v. via a constant infusion and the ED50 of each neuromuscular blocking agent was then administered (n = 24). Adenosine 0.1 mg kg-1 min-1 increased significantly maximal block induced by the ED50 of these neuromuscular blockers (55-72%, 49-73% and 60-96%, respectively, for rocuronium, vecuronium and pipecuronium; P < 0.05). Time to maximal block after rocuronium was significantly prolonged by adenosine (1.4-2.1 min; P < 0.05) and time to maximal block after vecuronium and pipecuronium was unchanged by adenosine. Time to maximal recovery of twitch tension after administration of the ED50 of all neuromuscular blocking agents was prolonged significantly by adenosine (4.5-10.7 min, 8.2-15.8 min and 47.0-128.7 min, respectively, for rocuronium, vecuronium and pipecuronium; P < 0.05). We conclude that continuous infusion of adenosine 0.1 mg kg-1 min-1 potentiated the effects of neuromuscular blocking agents in this in vivo guinea-pig preparation.

Adenosine↗
PubMed2000

Effect of thrombopoietin on proliferation of blasts from patients with myelodysplastic syndromes.

Thrombopoietin (TPO), a major cytokine involved in megakaryocytopoiesis/thrombopoiesis, may be effective for treatment of the thrombocytopenia associated with myelodysplastic syndromes (MDS). However, it has been unclear whether TPO stimulates proliferation of MDS blasts, as observed in de novo acute myeloid leukemia. This study examined this concern. When marrow cells from 37 MDS cases were cultured with or without recombinant human PEGylated TPO, TPO increased the blast number (stimulation index > or =1.5) in 9 of 16 high-risk MDS cases (refractory anemia with excess blasts [RAEB] and RAEB in transformation) and 4 of 10 cases with MDS transformed to acute leukemia (MDS-AL), but none of 11 cases with low-risk MDS (RA and RA with ringed sideroblasts). When the cell cycle of cultured cells was determined by three-color flow cytometry, TPO activated the cell cycle of MDS cells (causing a decrease in G(0)-phase cells) in most of the cases whose blast number increased in response to TPO. Reverse transcriptase-polymerase chain reaction analysis detected TPO receptor messenger RNA in purified blasts from all six cases examined, irrespective of the response of their blasts to TPO in culture. Analysis of the patients' characteristics identified a high-serum lactate dehydrogenase (LDH) value as being associated with blast proliferation in high-risk MDS cases (p = 0.0036). We conclude that TPO stimulates in vitro proliferation of blasts from a fraction of MDS patients. High-risk MDS patients, especially those who have a high-serum LDH value, and MDS-AL patients should be monitored with particular care in clinical trials of TPO for MDS.

Adult↗
PubMed2000

[Diagnostic imaging of malignant lymphoma: current usefulness and limitation].

The recent developments of imaging modalities allow us to make a diagnosis of malignant lymphoma, to determine its staging, and to evaluate its response to treatments noninvasively. Especially, CT and MR imagings can visualize almost all organs involved by lymphoma with high spatial and contrast resolutions. However, it is difficult to detect the small diseased lymph nodes and splenic lesions. The tumor viability after treatments can not be accurately evaluated with imaging studies. The coverage of the whole lymph nodes during one examination is not easily achieved, either. The multidetector CT system, fast MR imaging techniques, new MR contrast media, and PET are expected to overcome these difficulties.

Diagnosis, Differential↗
PubMed2000

Low proportion of G0-phase cells during induction chemotherapy correlates with subsequent remission in acute myeloid leukemia.

Kinetic resistance is assumed to be one of the main mechanisms of drug resistance in acute myeloid leukemia (AML), but the relationship between cell cycle status at diagnosis and achievement of complete remission (CR) is controversial. Based on the possibility that the cell cycle data after starting induction chemotherapy are more important than the pretreatment data, we used 3-color flow cytometry to examine the cell cycle (G0, G1, S, and G2/M phases) of AML cells on days 0, 5, and 9 of the first induction chemotherapy in 20 patients. Cell cycle data at these 3 time points were compared in the patients who achieved CR (CR cases) and in the patients who had persistent leukemia (non-CR cases) after the induction chemotherapy. In the CR cases, there was a tendency for the percentages of G0-phase AML cells on days 5 and 9 to be smaller than that on day 0, while the opposite tendency was observed in the non-CR cases. When cell cycle data were compared between the CR and non-CR cases, the percentage of G0-phase AML cells on day 9 differed significantly (CR cases 6.9% +/- 10.9%, non-CR cases 50.1% +/- 38.4%; P = .0024). This significance remained when the patients' AML subtype was taken into consideration. None of the other cell cycle data at each time point or the hematologic parameters, which may be related to CR achievement, showed differences between the CR and non-CR cases. We emphasize the importance of cell cycle analysis after initiating therapy and suggest that such analysis can identify refractory AML subjects. The identified subjects may be candidates for clinical trials of cell cycle modulators.

Acute Disease↗
PubMed2000

[Skeletal muscle T-cell lymphoma following hemophagocytic syndrome].

A 43-year-old man was admitted to our hospital because of hemophagocytic syndrome (HPS) in August, 1998. A CT scan, gallium scintigraphy, gastrofiberscopy and colonofiberscopy showed no evidence of malignant lymphoma. Virus-associated HPS was suspected because of an increased titer of anti-Epstein-Barr (EB) virus antibody (EBV VCA IgG 2,560x, EBV EA IgG 40x, EBNA 20x). The HPS resolved spontaneously for 40 hospital days, but two weeks into the period of HPS remission, the patient developed pain and marked swelling of the right thigh muscle, and pectoral, biceps brachii, quadriceps femoralis and masseter muscles. Otherwise, CT scan and gallium scintigraphy showed no abnormal findings. A biopsy of the right quadriceps femoralis muscle revealed non-Hodgkin's lymphoma with muscle infiltration. Immunohistologic examination confirmed T-cell type (CD3, CD43, CD45, CD45RO) lymphoma, and Southern blot analysis for T-cell receptor revealed a rearranged band. The lymphoma cells were negative for EBV genome monoclonality. The patient responded well to CHOP therapy and achieved a complete remission. This is considered a very rare case of T-cell lymphoma infiltrating multiple skeletal muscles following an episode of hemophagocytic syndrome.

Adult↗
PubMed1999

Growth of Escherichia coli in propofol, lidocaine, and mixtures of propofol and lidocaine.

BACKGROUND: Microorganisms grow rapidly in propofol. Extrinsic contamination of propofol is thought to be a source of postoperative sepsis and wound infection. We studied growth of a strain of Escherichia coli in thiopental, propofol, lidocaine, and mixtures of propofol and lidocaine. METHODS: The pathogen was exposed to 2.5% thiopental; 1.0% propofol; 1.0%, 2.0% and 4.0% preservative-free lidocaine; and propofol solutions containing 0.25%, 0.5%, 1.0%, 2.0%, or 4.0% lidocaine for 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 h at room temperature, respectively. The inocula from these suspensions were cultured for 48 h at 37 degrees C after the antimicrobial activity of the local anesthetics in the inocula was inactivated by a 1:1000 dilution with distilled water. RESULTS: No organisms grew after exposure to 2.5% thiopental. The exposure of E. coli to propofol increased the colony count to approximately 90 times the control count. The colony counts of E. coli after exposure to 1.0%, 2.0% and 4.0% lidocaine and 0.25%, 0.5%, 1.0%, 2.0% and 4.0% lidocaine in 1.0% propofol were lower than the counts after exposure to 1.0% propofol (P = 0.0048, 0.0027, 0.0003, 0.0503, 0.0188, 0.0080, 0.0044, and 0.0001, respectively). The growth rate of the microorganism was significantly higher in cultures exposed to 1.0% propofol than that in cultures exposed to lidocaine alone or lidocaine-propofol mixtures (P < 0.0001, respectively). CONCLUSION: Lidocaine possesses bacteriostatic activity against E. coli. Addition of lidocaine to propofol confers its bacteriostatic activity to the mixture and may decrease the hazard of infection associated with the extrinsic contamination of propofol.

Anesthetics, Intravenous↗
PubMed1999

Immunological reconstitution after cord blood transplantation for an adult patient.

We transplanted 4.1x10(7) unrelated umbilical cord blood cells into a 27-year-old patient suffering from transformed acute myelocytic leukemia. The thawing method was the same as described by Rubinstein et al (Proc. Natl. Acad. Sci. USA 1995; 92: 10119-10122). ANC reached over 500x10(9)/l on day 19, and the patient was free from RBC and platelet transfusion on days 26 and 38, respectively. Cytogenetic and molecular analysis after transplant revealed complete chimerism. The CD3+CD4+ lymphocyte count became greater than 100x10(9)/l at 5 weeks after transplantation. The CD3+CD8+ count became greater than 500x10(9)/l at 7 weeks and thereafter progressively increased in spite of administration of CYA. This immunological reconstitution pattern after umbilical cord blood transplantation was different from that after bone marrow transplantation, and resistance of CD3+CD8+ lymphocytes to CYA was the distinguishing characteristic. The rapid hematological recovery and immunological reconstitution may be attributed to the high dose of transfused nucleated cells and umbilical cord blood transplantation may become a promising method for treatment for such cases.

Adult↗
PubMed1999

Establishment of a near-triploid human B-cell lymphoma cell line with t(14;18) and a p53 gene point mutation.

We report a rare large B-cell non-Hodgkin's lymphoma having a characteristic near-triploid cell population with add(17)(p22) and t(14;18)(q32;q21) translocation. We also established and characterized a new cell line (TK cell) derived from the present lymphoma. A codon 180 mutation (GAG --> GAT) in the p53 gene was detected. t(14;18)(q32;q21) was revealed juxtaposition of the bcl-2 and JH genes. Immunoprecipitation analyses of p53 and bcl-2 revealed that abnormality of the p53 protein and aberrant bcl-2 expression, which may protect cells from apoptosis, may be critical to the development of leukaemogenesis exhibiting near-triploid chromosomes.

Aged↗
PubMed1999

Response to vecuronium in a patient with facioscapulohumeral muscular dystrophy.

Increased sensitivity to vecuronium has been noted in patients with Duchenne muscular dystrophy. We report the response to vecuronium in a patient with facioscapulohumeral muscular dystrophy (FSHD), an autosomal dominant disorder with an incidence of 10-20 cases per million. In this patient, sensitivity to an initial dose of vecuronium (0.02 + 0.08 mg kg-1) was normal, but recovery was faster and the effect of incremental doses of vecuronium (0.02 mg kg-1) was less than expected. Onset time and 25% recovery of T1/T0 after the intubating dose of vecuronium were 240 s and 22 min, respectively. Recovery index (spontaneous recovery of T1/T0 from 25% to 75%) was 9 min.

Adult↗
PubMed1999

[Clinical effects of combination therapy with cefozopran and tobramycin for severe infections in patients with hematologic diseases].

We studied clinical effect of a combination therapy with cefozopran (CZOP) and tobramycin (TOB) for infections in 80 patients with hematologic diseases in 15 institutes. Combined doses with CZOP 2 g and TOB 60-90 mg twice a day had been given intravenously. Of the 80 patients, 61 patients (42 with acute leukemia, 10 with malignant lymphoma, 3 with aplastic anemia, 2 with chronic myeloid leukemia, 2 with multiple myeloma, and 2 with myelodysplastic syndrome) were evaluable. Those consisted of 6 patients with septicemia, 49 with suspected septicemia, 3 with pneumonia, and 3 with other infections. Clinical efficacy by the treatment was excellent in 24, good in 17, fair in 9, and poor in 11 patients, and the overall efficacy rate including excellent and good was 67.2%. Microbiologically, 5 of the 6 patients with septicemia (1 coagulase negative Staphylococcus, 2 S. pneumoniae, 1 S. oralis, and 1 E. coli) were responded. The efficacy rate in patients with severe granulocytopenia showing 100/microliter or lesser neutrophil counts during the drug administration was 57.1% (12/21). Side effects and abnormal changes of clinical laboratory findings were observed in 5 patients, and 16 patients, respectively, but most of them were mild. The findings above suggested that the combination therapy with CZOP and TOB is useful as an empiric therapy for severe infections in patients with hematologic diseases.

Adult↗
PubMed1999

[Efficacy of the cuffed oropharyngeal airway in spontaneously breathing patients].

A cuffed oropharyngeal airway (COPA) was used in 20 adult patients for airway management under epidural and brachial plexus block supplemented with light general anesthesia. Insertion of a COPA was successful at first attempt in 17 of 20 patients (85%). Sore throat developed in one patient (5%). Aspiration regurgitation, or laryngospasm was not observed. We conclude that a COPA can be an efficient airway device is spontaneously breathing patients under anesthesia.

Adult↗
PubMed1999

[Anesthetic management of a patient with hypohidrotic ectodermal dysplasia].

Hypohidrotic ectodermal dysplasia (HED) is a rare congenital anomaly complex characterized by hypodontia, hypotricosis and hypohidrosis. There have been only a few reports of anesthetic management of patients with HED. We managed a 20-year-old man with HED, who underwent debridement and skin grafting under epidural anesthesia, without untoward events. Potential problems in anesthetic management of patients with HED are also discussed.

Adult↗