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Biomedical subjects

B Han

Publications and source records attributed to B Han.

138 records · Page 8Linked to original sources
PubMed1992

Effects of dietary aluminum excess and manganese deficiency on neurobehavioral endpoints in adult mice.

Studies in mice have suggested that both dietary Al excess and dietary Mn deficiency promote oxidative tissue damage. To determine if these factors can interact to produce functional nervous system damage, female mice (N = 10-12 per group) were fed diets with control or low Mn (35 or 3 micrograms Mn/g diet) and/or control or high Al (25 or 1000 micrograms Al/g diet, Al as Al lactate) content for a 90-day period. No overt signs of neurotoxicity were observed in any group. Excess Al produced a threefold Al accumulation in both liver and brain, a slight acceleration of growth, decreased motor activity, decreased grip strength, and decreased startle responsiveness. Manganese deprivation led to liver, brain, and femur Mn depletion and reduced liver MnSOD activity but no neurobehavioral changes. No interactive effects between Al excess and Mn deficiency were observed. Neither Al excess nor Mn deficiency altered brain or liver lipid peroxidation measures. This study suggests that (1) subchronic dietary Al at doses of 1000 micrograms Al/g diet produces elevated brain Al and altered neurobehavioral indices in adult mice; (2) brain lipid peroxidation is not altered by this treatment; (3) dietary Mn deficiency does not influence Al neurotoxicity in adult mice.

Aluminum↗
PubMed1992

Regional differences in retinoid release from embryonic neural tissue detected by an in vitro reporter assay.

Retinoic acid and related retinoids have been suggested to contribute to the pattern of cell differentiation during vertebrate embryonic development. To identify cell groups that release morphogenetically active retinoids, we have developed a reporter assay that makes use of a retinoic acid inducible response element (RARE) to drive lacZ or luciferase reporter genes in stably transfected cell lines. This reporter gene assay allows detection of retinoids released from embryonic tissues over a range equivalent to that induced by femtomole amounts of retinoic acid. We have used this assay first to determine whether the floor plate, a cell group that has polarizing properties in neural tube and limb bud differentiation, is a local source of retinoids within the spinal cord. We have also examined whether the effects of exogenously administered retinoic acid on anteroposterior patterning of cells in the developing central nervous system correlate with differences in retinoid release from anterior and posterior neural tissue. We find that the release of morphogenetically active retinoids from the floor plate is only about 1.5-fold that of the dorsal spinal cord, which does not have neural tube or limb polarizing activity. These results suggest that the spatial distribution of retinoid release from spinal cord tissues differs from that of the neural and limb polarizing activity. This assay has also shown that retinoids are released from the embryonic spinal cord at much greater levels than from the forebrain. This result, together with previous observations that the development of forebrain structures is suppressed by low concentrations of retinoic acid, suggest that the normal development of forebrain structures is dependent on the maintenance of low concentrations of retinoids in anterior regions of the embryonic axis. This assay has also provided initial evidence that other embryonic tissues with polarizing properties in vivo release retinoids in vitro.

Animals↗
PubMed1992

[Alterations of Ulex europaeus agglutinin-1 receptor in human colorectal benign and malignant tumors].

The distributions and alterations of UEA-1 receptor in 116 human colorectal mucosa, included 20 normal mucosa, 16 inflammatory and 14 hyperplastic polyps, 34 adenomas, and 32 carcinomas, were studied with ABC technique. The results follow as: 1. There were positive staining of UEA-1 in proximal colon and negative in distal colon and rectum; 2. The frequency and intensity of UEA-1 receptor stained were increasing with the sequence of normal mucosa (7.7%), inflammatory polyps (25%), hyperplastic polyps (57.1%), adenomas (76.4%), and carcinomas (100%) in distal colon and rectum; 3. The staining pattern of UEA-1 in severe atypia adenomas was very similar to that in carcinomas and both of them were significantly difference from that in the other groups (P less than 0.05 or less than 0.01). The results suggested that UEA-1 receptor in distal colon and rectum may be considered as a probe studying course of malignant transformation and benefit to the diagnosis of carcinoma.

Adenoma↗
PubMed1991

Influence of dietary-induced copper and manganese deficiency on ozone-induced changes in lung and liver antioxidant systems.

The influence of an animal's copper (Cu) and manganese (Mn) status on its response to ozone was investigated in weanling mice. Control, Cu-deficient and Mn-deficient mice were exposed continuously to 1.2 ppm O3 or filtered air for 7 days. In control mice, ozone exposure resulted in higher lung activities of CuZnSOD, MnSOD and GPx. In contrast, Mn-deficient mice did not display increases in lung MnSOD, CuZnSOD or GPx activities following ozone exposure. Similarly, ozone-induced increases in lung CuZn-SOD and MnSOD activities were not observed in Cu-deficient mice, although lung GPx activity was increased in these mice relative to their air-breathing controls. These results show that an animal's Cu and Mn status can influence its response to ozone, and the data suggest that Cu- and Mn-deprived animals may be more susceptible to long-term or repetitive ozone exposure.

Animals↗
PubMed1991

Cognitive impairment in musculoskeletal pain patients.

To assess the incidence and relationship of cognitive/intellectual impairments to pain problems, seventy-three adults with musculoskeletal pain seen in a PM&R outpatient clinic were screened using the Neurobehavioral Cognitive Status Examination (NCSE). Subjective pain complaints were assessed using portions of the McGill Pain Questionnaire. Patients with prior diagnoses of neurocognitive problems or those who had taken narcotic analgesics in the last 24 hours were excluded. Results showed that 32 percent of subjects had impaired performance in at least one cognitive domain. Individuals with poorer performance on the NCSE had higher levels of reported pain or disability and psychological distress. Possible factors contributing to poor performance on cognitive tasks include psychological disorders or distress, undiagnosed organic brain dysfunction, social/psychological factors such as education, or a combination of these. Results suggest the need for further research to understand the relationship of poor performance on cognitive tasks to the etiology, maintenance and rehabilitation of pain problems.

Adult↗
PubMed1991

Radioimmunolocalization of human malignant tumors with In-111 labeled monoclonal antibody.

An anti-human colon carcinoma monoclonal antibody 2C10 was radiolabeled with In-111 and studied in 15 patients with gastrointestinal and ovarian carcinoma. The labelling efficiency approached 100% and immunoactivity of the labeled antibody was over 75%. 2-3 mCi (1 mg) In-111-2C10 was given to the patients intravenously and scintigraphy was performed 72 hours after administration with a gamma camera. Specimens were also scanned in some of the patients. The resected tumors and remote margin were examined immunohistochemically. Positive scintigraphic images were obtained in 12/15 patients with colorectal cancer (10) and ovarian cancer (2). Negative results were seen in the two patients with gastric cancer. The scintigraphic results of 10 patients were confirmed surgically and pathologically. The remaining 5 were confirmed by endoscopy, B-ultrasonography or X-ray CT. Most patients had been definitely diagnosed before imaging except one patient with metastatic focus from ovarian cancer to colon and one with recurrent colon cancer were first detected with RIAD, showing the unique advantage the latfer. The high background radioactivity in the liver, however, is a conspicuous problem to be solved.

Adult↗
PubMedDate not supplied

Auditory startle in Swiss Webster mice fed excess aluminum in diet.

Using an automated method, reduced auditory startle responsiveness was detected in Swiss Webster mice fed excess aluminum in diet (1000 micrograms Al/g) as compared to controls (7 micrograms Al/g). Excess aluminum diets were fed either from conception to weaning (developmental group) or from conception and continuing to 52 days of age (continuous group). At 22 days of age, lower response amplitudes were seen in the aluminum exposed groups than in controls. At 52 days of age, more rapid reduction in response amplitude across initial trial blocks was noted. Effects were more prominent in the continuously exposed than the developmentally exposed group at 52 days of age. Reduced auditory startle responsiveness is interpreted as part of a pattern of subtle motor impairment and marginally reduced activity and responsiveness in mice fed excess aluminum in diet.

Acoustic Stimulation↗
PubMedDate not supplied

Tolerance limits of liver grafts with 30 minutes of warm ischemia to cold preservation in swine.

AIM: The aim of this study was to investigate the safe time limits of cold preservation in University of Wisconsin (UW) solution of liver grafts subjected to warm ischemia (WI) for 30 minutes from non-heart-beating donors (NHBDs). METHODS: The safe time limits were studied in a simple porcine orthotopic liver transplantation (LTx) model. In donors, livers were subjected to 30 minutes of WI and subsequent 6-hour (Group 1, n = 5), 10-hour (Group 2, n = 5), and 14-hour (Group 3, n = 3) cold preservation in UW solution. RESULTS: All 5 animals in Group 1 survived up to 7 days, the survey endpoint. In Group 2, only 2 animals survived to the same survey endpoint. All animals in Group 3 died within 12 hours. The 1-week survival rate of Group 1 was significantly higher than those of the other 2 groups. Group 1 showed a lower level of alanine aminotransferase (ALT) or aspartate aminotransferase (AST) after LTx, less pathological damage, higher concentration of adenosine triphosphate (ATP), and higher microcirculation blood flux in the grafted liver tissue at 1 hour after reperfusion than the other 2 groups. CONCLUSIONS: It is concluded that about 6 hours is the safe time limit of cold preservation in UW solution for liver grafts from NHBDs subjected to WI for 30 minutes.

Adenosine↗
PubMedDate not supplied

Intramuscular selenium administration in selenium-deficient cattle.

Nine recently weaned Hereford heifers were randomly assigned to a control group (n = 3) or a treatment group (n = 6). The animals were selenium (Se) deficient (mean +/- SD blood Se concentration = 0.024 +/- 0.012 microgram/mL). They were maintained on a selenium-deficient diet, and on day 0 of the study the treatment group was given 0.05 mg Se/kg body weight intramuscularly, while the control group received a placebo. The Se concentration of blood, serum, and urine as well as the glutathione peroxidase (GSH-Px) activity of blood and serum was measured over an 84-day period. Peak blood Se and serum Se concentrations (mean +/- SD) in the treatment group occurred at 5 hours postinjection and were 0.131 +/- 0.028 microgram/mL and 0.154 +/- 0.027 microgram/mL, respectively. The mean blood Se concentration of the treatment group was greater (P < .05) than that of the control group for the first 28 days after injection. The mean serum Se concentration of the treatment group was greater (P < .05) than that of the control group for all times after injection, except for day 56. The mean (+/- SD) blood GSH-Px activity of the treatment group (12.0 +/- 2.3 mU/min/mg hemoglobin) was increased (P < .05) over the control group (2.0 +/- 1.4 mU/min/mg hemoglobin) by day 28 and continued to be greater (P < .05) throughout the 84 day postinjection period.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Extract from Arca granosa L. inhibits proliferation of human tumour cell lines with kidney and lung origin.

Marine organisms are being considered increasingly as sources of anti-tumour agents. The extract from Arca granosa L. has been shown to decrease the growth of tumours and this study was undertaken to determine its ability and mechanism of inhibition. The extract inhibited the proliferation of six human tumour cell lines from different origins with varying sensitivity. The cell lines Ketr-3, A549 and NCl-H460 with kidney or lung origins were more sensitive to the extract than those of the HepG-2, MCF-7 and MGC-803 cells from other origins. In the three sensitive cell lines (Ketr-3, A549 and NCI-H460) the extract was shown to block different phases of the cell cycle progression and inhibit DNA synthesis in a concentration-dependent manner. It was concluded that the extract from A. granosa is potentially a novel anti-tumour agent, especially on kidney and lung tumour cell lines.

Animals↗
PubMedDate not supplied

[An efficient mutational method for photosynthetic bacteria].

The pigment and auxotrophic mutants of Rhodobacter sphaeroides Y6 were obtained by treatment with ethyl methanesulfonate (EMS) followed by lithium chloride (LiCI). Treatment with 0.081 M EPS and subsequent treatment with 0.071 M LiCI resulted in 12% higher frequency of pigment mutations than application of 0.081 M EMS alone; the frequency of auxotrophic mutations increased 2.5-fold when treatment with lithium chloride was applied. A blue shift 10 nm was recorded in the absorption spectrum of carotenoids form YM5-3 green mutant; considerable accumulation of neurosporine was revealed by HPLC and mass spectrometry. The method is efficient for isolating mutants of photosynthetic bacteria.

Ethyl Methanesulfonate↗