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Biomedical subjects

M Tan

Publications and source records attributed to M Tan.

At least 181 records · Page 10Linked to original sources
PubMed1989

Onchocerca volvulus recombinant antigen: physical characterization and clinical correlates with serum reactivity.

An Onchocerca volvulus cDNA clone expressing epitopes found in adult and larval parasites, designated lambda RAL-2, was derived from a 1,000-base message present in adult O. volvulus, which encodes a protein with an apparent molecular weight of 17,000. This protein does not appear to be extensively posttranslationally modified. Serum samples from 52 individuals exposed to O. volvulus were examined for antibodies recognizing the lambda RAL-2 recombinant antigen; 77% produced such antibodies. In addition, individuals producing antibodies recognizing the recombinant antigen were significantly less likely to develop some aspects of ocular pathology associated with O. volvulus infection than were individuals who did not do so. These results suggest that recombinant antigens such as that produced by lambda RAL-2 may be useful in attempts to understand the mechanism of O. volvulus-induced ocular pathology.

Adult↗
PubMed1989

Effects of low-dose marine oils on intimal hyperplasia in autologous vein grafts.

The effects of low-dose cod-liver oil on intimal hyperplasia of vein grafts were examined in 45 adult mongrel dogs undergoing peripheral arterial reconstruction. Fifteen animals served as the control group, 15 animals were fed a fish-oil supplement containing 240 mg of eicosapentaenoic acid daily, and a further 15 animals received 480 mg of eicosapentaenoic acid daily. Segments of undistended external jugular vein were anastomosed to bilaterally divided femoral arteries. The grafts were harvested at 6 weeks and intimal thickness was measured with a computerized interactive image analyzing system. Serum cholesterol level, prothrombin time, partial thromboplastin time, bleeding time, and platelet counts were measured before the operation and at 2, 4, and 6 weeks after the operation. Plasma levels of thromboxane B2 and prostaglandin F1 alpha and serum levels of eicosapentaenoic acid were measured before and 4 weeks after the operation. Serum cholesterol level increased similarly and significantly in all animals. Serum levels of eicosapentaenoic acid rose proportionately with the oral ingestion of fish oil but did not affect coagulation parameters. Plasma thromboxane B2 and prostaglandin F1 alpha were not significantly affected by the ingestion of marine oils. Intimal thickness was 39 +/- 5 microns in the control dogs. Ingestion of 240 mg of eicosapentaenoic acid reduced intimal thickness to 24 +/- 3 microns at 6 weeks (p less than 0.01). Increasing the dose by a factor of 2 did not decrease intimal thickness further, the intima being 23 +/- 2 microns (p less than 0.005). Our data indicate that small doses of fish oil will reduce intimal proliferation in autologous vein grafts and that marine oils may exert their beneficial effects on intimal hyperplasia by a mechanism other than their known effects on prostanoid metabolism.

Animals↗
PubMed1989

[Study on application of Tf subtyping in forensic medicine].

Tf is an important genetic marker for both parentage testing and personal identification in forensic medicine. It is valuable in anthropology, genetics and clinical medicine. We examined the Tf subtypes in the human serum and dried bloodstain using the ULPAGIF method. Tf subtyping was performed in four disputed parentage cases. One of the alleged fathers was excluded. Tf subtypes were successfully demonstrated from dried bloodstains kept at 4 degrees C for up to four weeks. In bloodstains kept at room temperature and 37 degrees C, the 100% of Tf subtyping was no longer possible after two weeks (or one day). It was suggested that the bloodstains should be examined no longer than seven weeks if the bloodstains were kept at room temperature; or otherwise they should be stored below 4 degrees C as soon as they are collected in forensic practice.

Blood Stains↗
PubMed1986

Assessment of host immune response in breast cancer patients.

Cell-mediated immune status of breast cancer patients was evaluated by percentage of T gamma cells, natural killer (NK) activity, and the augmentation of NK cells by interferon. The patients with breast cancer did not show impaired cell-mediated immune responses until they were in the late stage of cancer. Sixty-one patients with breast cancer revealed higher proportions of T gamma cells measured by a new method utilizing microplate compared with those of 50 healthy subjects. Reduced NK activity was seen in the patients with stage III or IV breast cancer. Natural cytotoxicity against K-562 target cells was strongly augmentated by treatment with interferon in vitro for 2 hr, both in the patients with breast cancer and in healthy donors, except for far advanced breast cancer patients. A negative correlation between the percentage of T gamma cells and T cell was significant in the patients with primary breast cancer prior to radical mastectomy.

Adult↗
PubMed1985

[Significance of active nutritional support for maintenance of immunopotentiation on the surgical treatment of esophageal cancer].

The correlation between nutrition and immunological potentiation on patients with cancer of the esophagus was investigated in preoperative and postoperative periods. Preoperative immunological status: These patients were already suffering from malnutrition, because of the impossibility of peros intake. Natural killer (NK) cell activity and interleukin-II inducing activity of peripheral mononuclear cells in the above patients were clearly lower than such activities of cells in the patients with breast cancer whose nutritional condition was as normal as that of healthy people. These two immunological parameters in the majority of the patients were improved by active total parenteral and enteral nutrition. However, there were a few patients whose nutritional status could not be improved. Postoperative immunological status: The movement of peripheral lymphocyte subpopulation was successively checked with several kinds of monoclonal antibodies such as OKT-3 (anti-T cells), Leu-7 (anti-NK cells), OKIa-1 (anti-B cells), OKT-4 (anti-inducer and/or suppressor T cells) and OKT-8 (suppressor and/or cytotoxic T cells). In nutritionally controlled patients, the population of OKT-3, Leu-7 and OKIa-1 showed a pattern similar to the preoperative value, but in undernourished patients, that population was disturbed soon after the operation. Patterns of OKT-4 and OKT-8 showed a converse correlation. Nearly two weeks after operation, all these five kinds of population had changed. Moreover, nitrogen balance recovered from negative to positive. The time of is thought to be the turning point of surgical metabolism and the immunological status.

Esophageal Neoplasms↗
PubMed1984

Postoperative cancer therapy for patients with carcinoma of the thoracic esophagus: an attempt of aggressive chemotherapy combined with proper nutritional support for patients with distant node metastasis.

The prognosis of patients with advanced thoracic esophageal carcinoma is still poor. In general, patients having distant lymph-node metastasis do not survive for more than 3 years. Therefore, a new therapeutic regimen employing aggressive chemotherapy for these patients has been attempted. In this regimen, three kinds of anticancer drugs Pepleomycin, and twice as much as Adriamycin and Mitomycin of the conventional level for a short period of time are used. Eleven cases were treated with this chemotherapy under active enteral and parenteral nutritional support of 45 to 50 kcal/kg daily. Two patients over 70 years of age died of pneumonitis. Four patients with recurrence of cancer in the lungs, liver and cervical nodes died after 10, 12, 13 and 14 months following surgery, respectively. Five patients have been alive for more than 2 years. These results indicate that this therapy is more effective than other conventional therapies. It has been shown that aggressive chemotherapy combined with proper nutritional support is effective for patients with node metastasis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1982

Cloning of adeno-associated virus into pBR322: rescue of intact virus from the recombinant plasmid in human cells.

We have cloned intact duplex adeno-associated virus (AAV) DNA into the bacterial plasmid pBR322. The AAV genome could be rescued from the recombinant plasmid by transfection of the plasmid DNA into human cells with adenovirus 5 as helper. The efficiency of rescue from the plasmid was sufficiently high to produce yields of AAV DNA comparable to those observed after transfection with equal amounts of purified virion DNA. Thus, the recombinant plasmid itself may be a model for studying the rescue of a latent AAV viral infection. In addition, the efficient rescue of viable AAV from the recombinant plasmid should facilitate the genetic analysis of AAV. Finally, the results of an analysis of the DNA from rescued virions indicate that an inversion of the AAV terminal sequences occurred during replication.

Cells, Cultured↗
PubMed1982

Simple daily technique to calculate total and interim changes of daily O2 consumption and CO2 production in premature infants.

A simple method to calculate oxygen consumption (VO2) and CO2 production (VCO2) over a 24-h period is described. VO2 and VCO2 were measured using flow-through technique and the total VO2 and VCO2 over a given period of time were determined from the area under the O2 and CO2 concentration-time curve of the mixed expired gas. The system was tested in vitro by burning 100% ethyl alcohol. The average error between measured and theoretical values for VO2 was 4.9% and for VCO2 was 4.7%. With a flow rate greater than 5340 ml/min through the system, the correlation coefficient between theoretical VO2 or VCO2 and measured VO2 or VCO2 was 0.99. The method was tested in vivo in 5 premature infants who were nursed under neutral thermal environment and received routine medical care. The results indicate that this simple method can be used to study the total and interim changes of daily VO2 and VCO2 in infants during their ongoing nursery care.

Carbon Dioxide↗
PubMed1980

Spontaneous antibody-secreting human blood lymphocytes detected with a protein A plaque assay.

Spontaneous antibody-secreting lymphocytes in human peripheral blood were detected and counted by a protein A plaque assay. The level of plaque-forming cells (PFC) in peripheral blood was significantly higher in patients with immune disorders (per 10(6) lymphocytes: IgG PFC, 2,654 +/- 684; IgA PFC, 1,727 +/- 327; IgM PFC, 403 +/- 92) than in normal controls (per 10(6) lymphocytes: IgG PFC, 327 +/- 56; IgA PFC 633 +/- 128; IgM PFC, 215 +/- 105). There was no direct correlation between the PFC numbers of different Ig classes.

Adolescent↗
PubMed1979

On a new continuous cell line (TM-1) derived from malignant melanoma.

A continuous cell line of malignant melanoma has been established. The tumor specimen was obtained from a left axillary lymph node of a malignant melanoma originating in the abdominal skin of a 67-year-old woman. The cell line has been designated TM-1. Explant specimens showed positive dopa staining, but after 2 years and 4 months, or 60 generations of cell passage, the dopa staining is now weakly positive. Treatment with DBcAMP that causes marked morphological changes induces melanin production and lowers the proliferative ability of the cells. These changes were reversible. Transplantation of the cells to nude mice resulted in the formation of large tumors consisting of epithelioid cells and spindle cells. Morphologically, the majority of the cell population in vitro was polygonal epithelioid cells, but the cell passage produced a large number of spindle cells. The shape of the TM-1 cells was examined by scanning electron microscopy. Depending upon the culture conditions, either of these cell types could be predominated, indicating that both cells are of the same origin.

Aged↗