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Biomedical subjects

J Kong

Publications and source records attributed to J Kong.

At least 91 records · Page 5Linked to original sources
PubMed1995

Quantitative in situ image analysis of apoptosis in well and poorly differentiated tumors from rat liver.

The evaluation of apoptosis is an important aspect in the study of chemical carcinogenesis. Methods were developed employing the ApopTag kit (Oncor, Gaithersburg, MD) and automated image analysis to quantitate the distribution of apoptosis in formalin-fixed, paraffin-embedded liver tumor sections from rats induced by 2-acetylaminofluorene. Specific treatments of tissue sections were developed that permitted quenching of background tissue autofluorescence with crystal violet and permitted permeating the fixed tissue sections by trypsin digestion. Tissue sections were stained by using the ApopTag kit for detection of in situ apoptosis and with propidium iodide as a counterstain for tissue nuclei. Automated statistical evaluation of the percentage of tissue nuclei also staining positively for apoptosis was determined by using dual fluorescence detection and imaging laser microscopy. The quantitative results indicated that the staining index for apoptosis in normal liver was 0.14 +/- 0.04% whereas well and poorly differentiated tumors showed increases of 3.48 +/- 0.59% and 7.41 +/- 0.81%, respectively. The staining indexes for apoptosis showed a tight correlation between fluorescent and peroxidase-diaminobenzidine detection in sequential tissue sections. The use of in situ apoptosis staining and automated image analysis for rapid identification and quantitation of cells undergoing death in fixed tissue will expedite additional studies to evaluate the in situ tissue pathobiology of tumors and aid in the study of molecular mechanisms associated with cancer development and treatment.

2-Acetylaminofluorene↗
PubMed1995

Fluoride content of Los Angeles County water.

A series of tap water samples were collected from residents in various areas of Los Angeles County. Three samples were collected each week over a period of three weeks, for a total of nine samples from each of the 45 residences. Samples were analyzed for fluoride content, and the data compared to information received from the agencies supplying the source water. Fluoride levels varied an average of .11 ppm during the three-week collection period; mean levels were consistently higher than values reported by the various agencies.

Fluoridation↗
PubMed1994

Enhancement of J6-1 human leukemic cell proliferation by cell-cell contact: role of an M-CSF-like membrane-associated growth factor MAF-J6-1.

Density-dependent cell proliferation and cluster formation are growth phenotypes frequently associated with leukemia cells. The secretion of autocrine growth factor, such as granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin 1 (IL-1), has been implicated as one possible mechanism in leukemogenesis. In many cases, however, leukemia cells do not appear to produce autocrine growth stimulators. J6-1 is an established human myeloid leukemia cell line that exhibits both density-dependent and cluster-forming growth characteristics. The effect of direct cell-cell contact on J6-1 cell proliferation was investigated. We have isolated from J6-1 cells a membrane-bound factor (designated as MAF-J6-1) that promoted the colony formation by both J6-1 cells and mouse bone marrow CFU-GM. The growth-promoting activity of MAF-J6-1 can be neutralized by either anti-macrophage-CSF (M-CSF or CSF-1) or anti-MAF-J6-1 monoclonal antibodies (MAb), suggesting that MAF-J6-1 is related to M-CSF. Using an immunoblot analysis with anti-MAF-J6-1 MAb, the MW of this membrane-associated factor was estimated to be 80 kDa. Both antibodies also induced a modest growth inhibition on J6-1 cells in vitro. Similarly, addition of exogenous recombinant human M-CSF augmented the colony formation by J6-1 cells, an effect also neutralized by both antibodies. Using an in situ hybridization technique, J6-1 cells were found to express a high level of c-fms proto-oncogene, which encodes the receptor for the M-CSF. Taken together, our results suggest that the membrane-bound MAF-J6-1 promote J6-1 cell proliferation and cluster formation through a 'juxtacrine' mechanism.

Cell Communication↗
PubMed1993

Effect of caloric restriction on aflatoxin B1-induced DNA synthesis, AFB1-DNA binding and cell proliferation in Fischer 344 rats.

Young adult male Fischer rats maintained on a reduced calorie diet (60% of ad libitum food consumption) for 6 weeks showed a decrease in the binding of aflatoxin B1 (AFB1) to hepatic or renal nuclear DNA and a reduction of AFB1-induced hepatocellular damage. Repeated dosing of rats with AFB1 resulted in the inhibition of hepatic and renal DNA synthesis measured by [3H]thymidine incorporation. However, the rate of DNA synthesis was greater in ad libitum (AL) rats than in calorically restricted (CR) animals. Three days after AFB1 dosing, the rate of DNA synthesis had recovered to the control level. Cell cycle analyses measured by a flow cytometric method on kidney cells of both AL and CR rats showed that there were no significant changes in cell populations in the S phase between these two groups of rats. AFB1 inhibited the cell proliferation on an average of 33%. The restoration of the cell proliferation in kidney cells was found on the third day after AFB1 dosing. The rate of the regenerative cell proliferation was found to be slightly greater in AL rats than in CR animals. The AFB1-induced regenerative DNA synthesis in both liver and kidney was retarded by CR.

Aflatoxin B1↗
PubMed1993

Triterpenoid glycosides from Decaisnea fargesii.

Five new triterpenoid glycosides designated decaisosides A-E together with five known ones were isolated from the stems of Decaisnea fargesii. Their structures were established by means of chemical and spectroscopic evidence.

Carbohydrate Sequence↗
PubMed1993

Effect of caloric restriction on the metabolic activation of xenobiotics.

The effect of caloric restriction (CR) on xenobiotic metabolizing enzyme activities results in alterations in the metabolic activation of chemical carcinogens, with a resultant impact on DNA-carcinogen adduct formation and DNA repair. Using aflatoxin B1 (AFB1) and benzo[a]pyrene (BP) as model carcinogens, we studied the effect of CR on the metabolic activation of these carcinogens and carcinogen-induced DNA damage and repair in terms of AFB1-DNA and BP-DNA adduct formation and removal. Male Fischer 344 rats fed calorie restricted diets (60% of the food consumption for ad libitum-fed rats) showed a reduction in the metabolic activation of AFB1 and decrease in both the in vitro and in vivo AFB1-DNA adduct formation. However, CR increased the activity of BP metabolizing enzymes resulting in an enhancement of BP-DNA adduct formation. Our results indicate that the effect of CR on metabolic activation of xenobiotics is dependent upon the selected xenobiotic metabolizing enzymes whose activities may be significantly altered by CR, and upon the nature of the chemical carcinogens which exert different structure-activity relationships during the process of chemically induced carcinogenesis.

Aflatoxin B1↗
PubMed1993

Airway resistance and work of breathing in tracheostomy tubes.

Recommendations for sizing of tracheostomy tubes are generally based on anatomic considerations with the largest fitting tube most commonly placed. Once in the tracheostomy site, the tube assumes the new role of the upper airway. Consideration of the airway resistance of each tracheostomy tube and change in work of breathing are important in maintaining the respiratory system homeostasis. The airflow dynamics of neonatal, pediatric, and adult tracheostomy tubes were studied. Flow rates were plotted against change in pressure for inspiratory and expiratory flows and resistances for each tube were calculated. The expiratory resistances were larger for the neonatal tubes and pediatric tubes 0 and 00, while inspiratory resistances were the limiting factor in the adult tubes and the larger pediatric tubes. Comparison of calculated resistances of the tracheostomy tubes was made with known physiologic airway resistances. Adult tubes 8 and 10 most closely simulated the upper airway resistance of adults and neonatal tube 0 appeared most appropriate for the newborn. Work of breathing was determined for each tracheostomy tube. Increasing tube diameter as well as decreasing tidal volume and respiratory rate decreased the amount of work required to maintain a given flow.

Adult↗
PubMed1993

[Thermostability and immunogenicity of trivalent oral poliovirus vaccine produced by different countries].

Hep-2 cell-based microtiter assay system was used to test the titer of TOPV(Sabin strain). Before immunization, the overall potency results of TOPV produced by China, Yugoslavia, and Belgium were 6.38, 6.25, and 5.75 log TCID 50/0.1 ml, respectively. After storage at 37 degrees C for 2 days or after 5 cycles of freezing and thawing, the overall titer of each TOPV reduced less than 0.5 log TCID 50/0.1 ml. A randomized study was conducted in Anhui Province to test the serological difference among the TOPV which were produced by China, Yugoslavia and Belgium. The formulations of the TOPV produced by China and Yugoslavia were 6.0, 5.0, and 5.5 log TCID 50/0.1 ml of Sabin types 1, 2, and 3, respectively. All of the children in this study were divided into three groups, and children in group A, B, and C received TOPV produced by China, Yugoslavia, and Belgium, respectively. Three doses of TOPV were given to the children in the group at 2, 3, and 4 months of age. The seroconversion rates and geometric mean titers had no significant differences among these groups before immunization. At the end of one month following the 2nd dose, the rates of seroconversion to type 1-3 poliovirus in group A, B, and C were 88%, 98%, 98%; 92%, 98%, 92%; 100%, 100% and 96%, respectively. The rate of seroconversion to type 1 poliovirus in group C was higher than those in group A and B.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Viral↗
PubMed1992

A retrospective mortality cohort study of chrysotile asbestos products workers in Tianjin 1972-1987.

The mortality rate of a cohort of asbestos workers was investigated in Tianjin, China, between January 1, 1972, and December 31, 1987. The cohort consisted of 662 males and 510 females, employed in asbestos textiles, friction material, and asbestos cement manufacturing. A statistically significant excess mortality was observed for lung cancer in both males and females (SMR 278 and 427, respectively). An increasing trend in SMR was observed with increasing intervals of exposure as well as with increasing exposure level. A synergistic effect was seen between asbestos exposure and cigarette smoking regarding lung cancer. The ratio of smoking and nonsmoking lung cancer death rates was virtually the same in asbestos and in nonasbestos workers. This ratio was approximately 1.6, a value much less than that reported in other countries. This low ratio appears to reflect the fact that many nonsmokers were in fact passive cigarette smokers. Second, it reflects the fact that most smokers smoked hand-rolled tobacco, since manufactured cigarettes did not become popular in China until 1965. These data confirm the hazards of asbestos exposure in developing countries.

Adolescent↗
PubMed1991

Investigation of the effects of beta-2 stimulation on free fatty acids in man.

In this study we present evidence that lipolysis in man is under beta-2 adrenergic control and that beta-2 stimulation produces a characteristic profile of individual free fatty acid (FFA) release. Twelve healthy volunteers received infusions of placebo (N Saline), terbutaline (a selective beta-2 agonist) and dilevalol (a new non-selective beta-blocker with beta-2 agonist activity). Plasma FFA concentrations during and after the infusions were measured using gas chromatography. A significant rise in total and individual FFAs was seen after 30 min of terbutaline infusion. This was most marked for oleic acid. Total and individual FFA concentrations also rose after 30 min of dilevalol infusion; this was only significant for oleic acid and was approximately 15% of the rise induced by terbutaline infusion. Placebo infusion did not cause any significant changes in FFA levels.

Adult↗
PubMed1991

[The prehospital emergency cardiac care in patients with acute myocardial infarction].

In order to evaluate the current status of prehospital care of acute myocardial infarction (AMI) in this city, the clinical manifestations and the emergency cardiac care in prehospital phase in 210 patients were reviewed in the period from 1987 to 1988. Before admission to CCU, 45.7% of the patients had complications of severe cardiac arrhythmias or hemodynamic disturbances and 14.8% had cardiac arrests. The mortality during the first 4 weeks was 25.2%. Among 53 patients who died, 50.9% occurred before admission and 37.7% within 1 hour. One hundred and ten patients (52.4%) had prehospital care and, 4 of them provided by the City Emergency Center and others by the local clinics near by. The median time from the cardiac attack to the first medical care, hospital arrival and CCU admission was 2, 3.6 and 6.3 hours respectively. The management on the scene was not efficient and effective in many patients. The rate of successful resuscitation in patients who had cardiac arrest out of hospital was only 7.7%. We are impressed that the mortality of patients with AMI is mainly in the early stage after appearance of symptoms. The initiation of emergency cardiac care is very necessary. The current status of prehospital cardiac care needs to be improved immediately, some suggestions are made for this purpose.

Aged↗
PubMed1990

A seral epidemiological study of HIV transmitted through human seral gamma-globulin preparations.

In order to study the potential risk of transferring HIV through human seral gamma-globulin preparations (immunoglobulin), indirect immunofluorescent antibody test (IFA) and Western Blot (WB) assay were applied to 343 random samples (sera) with previous injection of imported human seral gamma-globulins (Ig) positive for Human Immunodeficiency Virus (HIV) antibodies between 1981-1987 for the detection of HIV antibodies. All results were negative and tests on all 23 controls who had previously received Ig made in China also gave negative results. However all 12 batches of imported Ig collected from the above-mentioned users, were positive for HIV antibodies when tested by WB and IFA. This study shows that under normal conditions, human seral gamma-globulin does not transmit HIV.

Adolescent↗
PubMed1987

Does radiotherapy have a role in hemangiopericytoma management? Report of 14 new cases and a review of the literature.

From 1948 to 1984, 14 adult patients received radiation therapy as a part of their treatment for hemangiopericytoma at the University of Texas M.D. Anderson Hospital and Tumor Institute at Houston. In addition to radiation therapy 11 patients were treated with surgery, with or without chemotherapy--5 as primary management and 6 after recurrence following surgical excision. Although 9 of these 11 patients had macroscopic and 1 had definite microscopic disease at the time of irradiation, none suffered local recurrence and 9 have survived from 3.5 years to 20 years free of disease. Two of the 11 patients died of distant metastases. Two patients completed treatment for palliation and 1 of them survived for 2 years after treatment. The results suggest that postoperative radiation therapy should be considered as an integral part of the primary treatment of hemangiopericytoma.

Adult↗
PubMed1987

Palliation of advanced pelvic malignant disease with large fraction pelvic radiation and misonidazole: final report of RTOG phase I/II study.

Between October 1979 and June 1982 forty-six patients were entered on a non-randomized Phase I-II protocol for the evaluation of Misonidazole combined with high dose per fraction radiation for the treatment of advanced pelvic malignancies. Pelvic radiation consisted of 1000 cGy in one fraction repeated at 4-week intervals for a total of three treatments. Oral Misonidazole at a dose of 4 gm/m2 was administered 4-6 hr prior to radiation (total dose 12 g/m2). The distribution of histology consisted of 20 gynecologic, 24 bowel, and 2 prostate malignancies. Of the thirty-seven patients completing the three treatments; there were 6 complete responses (14% CR), 10 partial responses (27% PR) 19 minimal or no response (32% NR), and 4 unevaluable. One patient remains NED 5.5 years following radiation. Toxicity directly related to Misonidazole was minimal and consisted primarily of transcient Grade 1, 2 peripheral neuropathy (20% Grade 1, 4% Grade 2) and Grade 2 ototoxicity (4%). Radiation toxicity was significant for late bowel damage. There were 4 (11%) Grade 3 and 7 (19%) Grade 4 gastro-intestinal (GI) toxicities. Kaplan-Meier plot of GI toxicity showed a progressive increase in incidence with time for projected rate of 49% Grade 3, 4 by 12-month. GI toxicity (Grade 3, 4) was also related to tumor response. The complication rate was 80% (4/6) for CR, 30% (3/10) for PR and 26% (5/19) for NR or progression. Because of the GI complication rate, this protocol for palliation of advanced pelvic malignancies has been replaced by a protocol that uses 4 fractions over 2 days (b.i.d.) of 370 cGy per fraction repeated at 3-week intervals for a total of 3 courses.

Combined Modality Therapy↗
PubMed1984

Non-Hodgkin's lymphoma of the tonsil. A clinicopathologic study of 65 cases.

Sixty-five patients presenting to M. D. Anderson Hospital and Tumor Institute with Stages IE and IIE primary tonsillar lymphoma between 1954 and 1981 were reviewed. All cases were non-Hodgkin's lymphomas, with the majority being diffuse large cell lymphoma (85%). Initial therapy was radiotherapy alone in 54 patients, radiotherapy combined with chemotherapy in 8 patients, and chemotherapy alone in 3 patients. Stage was the most important prognostic factor, with 86% and 41% 5-year survivals for Stages IE and IIE, respectively (P = 0.006). Lymphangiography was crucial in staging patients with clinically positive cervical lymph nodes because 94% of clinically staged IIE patients developed recurrent disease, in comparison with only 50% of lymphangiogram-staged IIE patients. The incidence of large cell lymphoma was so high as to preclude analysis of survival by histologic type. From this limited series, radiotherapy alone would appear to be sufficient initial therapy for Stage IE patients, whereas Stage IIE patients probably benefit from the addition of prophylactic chemotherapy. Relapses were most common in nonirradiated lymph-node-bearing areas, with the majority presenting in the first 2 years following initial therapy. The salvage of relapsing patients has been disappointing, with the best hope residing in combination chemotherapy.

Adolescent↗
PubMedDate not supplied

Electron beam therapy for eyelid carcinomas.

Forty-six (85%) basal cell and eight (15%) squamous cell carcinomas of the eyelids were treated with electron beams between 1963 and 1983. Lesion sizes ranged from microscopic to 4 cm, with 28 lesions larger than 1 cm. Thirty-eight lesions were treated with radiotherapy after incisional biopsy, and 16 were treated after excisional biopsy (specimens showed positive margins). Doses varied from 45 to 72 Gy, with daily fractions ranging from 2.12 to 4.0 Gy. There were six disease recurrences (10.9%): three in the treatment field and three at the treatment margin. Four of six recurrences were subsequently controlled by limited surgical excision and repair with preservation of the eye, whereas the other two required enucleation. Treatment sequelae such as skin atrophy, telangiectasis, and cosmetic results were evaluated in terms of radiotherapy parameters, pretreatment surgery, and size of the lesion. In 44 patients, the overall cosmetic result was judged as good to excellent, five patients had a mild to modest degree of deformity, and five had significant deformity. Such deformity was usually associated with tumor destruction or previous surgery. No major complications were noted.

Aged↗