Measurement of blood plasma amino acids in ultrafiltrates by high-performance liquid chromatography with automatic precolumn O-phthaldialdehyde derivatization.
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Age Factors↗
Biomedical subjects
H Liu
Publications and source records attributed to H Liu.
Mortality and time to death in very low birth weight infants: California, 1987 and 1993.
BACKGROUND: Recent advances in perinatal technology have dramatically increased the survival of very low birth weight (VLBW) infants (<1500 g). The possibility that these advances may also prolong the time to death and increase pain and suffering has been of concern, but there have been no population-based evaluations of this issue. METHODS: Infant, neonatal, and postneonatal mortality rates and time to death for infants 500 to 749 g, 750 to 999 g, 1000 to 1499 g, and all VLBW infants born during 1987 were compared with those outcomes for infants born in 1993 using statewide California linked birth/death cohort files. To assess the effects of improved survival and changes in time until death, we calculated the total days of life preceding an infant death per 1000 live born infants (TDD). RESULTS: VLBW infants comprised.96% of California's live births in 1987 and.92% of those in 1993. Between 1987 and 1993, VLBW infant mortality rate decreased 28.4% (from 290.7 to 208.3 per 1000 live born VLBW infants), VLBW neonatal mortality rate decreased 30. 3% (from 244.5 to 170.4), and VLBW postneonatal mortality rate decreased 25.3% (from 61.2 to 45.7 per 1000 VLBW alive at 28 days; P <.05 for each rate). Infant mortality rates decreased by 18.8% (718. 1 to 583.0 per 1000) for infants 500 to 749 g, 43.3% (375.1 to 202. 6) for infants 750 to 999 g, and 40.1% (127.9 to 76.7) for infants 1000 to 1449 g (P <.05 for each group). Neonatal mortality and postneonatal mortality rates also decreased in all 3 VLBW subgroups. These reductions in mortality rates were not accompanied by a significant difference in the distribution of times to death or a significant increase in the average time to death for all VLBW infants (22.0 vs 23.6 days) or for those with birth weights of 500 to 749 g (12.7 vs 71.5 days). Reduced mortality in larger infants was accompanied by an increase in the average time to death, from 24. 3 to 32.5 days in infants 750 to 999 g and from 32.3 to 47.0 days in infants 1000 to 1449 g. TDD decreased from 6410 to 4908 days for all VLBW infants. TDD was also reduced 26.4% (2401 days), 24.3% (2115 days), and 22.5% (1043 days) for the 3 VLBW birth weight groups. CONCLUSIONS: Both mortality rate and timing of death are important when assessing the impact of advances in perinatal technology. Although the average time to death was significantly increased in VLBW infants weighing >750 g, between 1987 and 1993, advances in perinatal technology dramatically decreased VLBW mortality. In the State of California in 1993, this resulted in 452 fewer VLBW deaths and 8233 fewer days preceding a VLBW death than expected.
California↗
Lentiviral vector transduction of hematopoietic stem cells that mediate long-term reconstitution of lethally irradiated mice.
Lentiviral vectors efficiently transduce human CD34(+) cells that mediate long-term engraftment of nonobese diabetic/severe combined immunodeficient mice. However, hematopoiesis in these animals is abnormal. Typically, 95% of the human cells in peripheral blood are B lymphocytes. To determine whether lentiviral vectors efficiently transduce stem cells that maintain normal hematopoiesis in vivo, we isolated Sca-1(+)c-Kit(+)Lin(-) bone marrow cells from mice without 5-fluorouracil treatment, and transduced these cells in the absence of cytokine stimulation with a novel lentiviral vector containing a GFP (green flourescent protein) reporter gene. These cells were transplanted into lethally irradiated C57Bl/6 mice. In fully reconstituted animals, GFP expression was observed in 8.0% of peripheral blood mononuclear cells for 20 weeks posttransplantation. Lineage analysis demonstrated that a similar percentage (approximately 8.0%) of GFP-positive cells was detected in peripheral blood B cells, T cells, granulocytes and monocytes, bone marrow erythroid precursor cells, splenic B cells, and thymic T cells. In secondary transplant recipients, up to 20% of some lineages expressed GFP. Our results suggest that quiescent, hematopoietic stem cells are efficiently transduced by lentiviral vectors without impairing self-renewal and normal lineage specification in vivo. Efficient gene delivery into murine stem cells with lentiviral vectors will allow direct tests of genetic therapies in mouse models of hematopoietic diseases such as sickle cell anemia and thalassemia, in which corrected cells may have a selective survival advantage.
Animals↗
Use of an intracranial near-infrared probe for localization during stereotactic surgery for movement disorders.
Localization of targets during stereotactic surgery is frequently accomplished by identification of the boundaries between the gray matter of various nuclei and the surrounding white matter. The authors describe an intracranial probe developed for this purpose, which uses near-infrared (NIR) light. The probe fits through standard stereotactic holders and emits light at its tip. The scattered light is detected and analyzed by a spectrometer, with the slope of the trailing portion of the reflectance curve used as the measurement value. Near-infrared readings were obtained during 27 neurosurgical procedures. The first three operations were temporal lobectomies, with values obtained from tracks in the resected specimen and resection bed. In the next five procedures, the probe was inserted stereotactically to a depth of 1 to 2 cm with measurements obtained every 1 mm. The probe was then used in 19 stereotactic procedures for movement disorders, obtaining measurements every 0.5 to 1 mm to target depths of 6 to 8 cm to interrogate subcortical structures. The NIR signals were correlated to distances beneath the cortical surface measured on postoperative computerized tomography or magnetic resonance imaging by using angle correction and three-dimensional reconstruction techniques. The NIR values for white and gray matter obtained during the lobectomies were significantly different (white matter 2.5+/-0.37, gray matter 0.82+/-0.23 mean +/- standard deviation). The NIR values from the superficial stereotactic tracks showed initial low values corresponding to cortical gray matter and high values corresponding to subcortical white matter. There was good correlation between the NIR signals and postoperative imaging in the 19 stereotactic cases. Dips due to adjacent sulci, a plateau of high signal due to subcortical white matter, a dip in the NIR signal during passage through the ventricle, dips due to the caudate nucleus, and peaks due to the white matter capsule between ventricle and thalamus were constant features. The putamen-capsule boundary and the lamina externa and interna of the globus pallidus could be distinguished in three cases. Elevated signals corresponding to the thalamic floor were seen in 10 cases. Nuances such as prior lesions and nonspecific white matter changes were also detected. There was no incidence of morbidity associated with use of the probe. Data acquisition was straightforward and the equipment required for the studies was inexpensive. The NIR probe described in this article seems to be able to detect gray-white matter boundaries around and within subcortical structures commonly encountered in stereotactic functional neurosurgery. This simple, inexpensive method deserves further study to establish its efficacy for stereotactic localization.
Brain↗
Effect of gliotoxin on development of diabetes mellitus in diabetes-prone BB/Wor rats.
The object of this investigation was to determine if gliotoxin, an immunomodulating fungal secondary metabolite, is capable of preventing the development of autoimmune diabetes mellitus in diabetes-prone BB/Wor rats. Chronic treatment, consisting of 1 microg gliotoxin/g of body wt administered three times weekly from the age of 30 days through 120 days, reduced the incidence of diabetes from 90% diabetic by 120 days among vehicle-treated animals to 56% diabetic among gliotoxin-treated animals. This result was significant by life table analysis. Animals treated with gliotoxin maintained lower serum glucose levels even in the pre-diabetic state than control (vehicle-treated) rats. Gliotoxin at levels used in this study showed no appreciable effect on the viability of rat insulinoma (RIN 38) cells in culture and only slightly decreased their insulin secretion. Animals chronically treated with gliotoxin showed weight gains comparable to those seen in controls, and the effect of gliotoxin on peripheral blood leukocyte counts was not significant. The possibility that gliotoxin exerted its effect through immunomodulating effects was implied by the loss of white pulp in splenic follicles of gliotoxin-treated animals.
Animals↗
[Computer modeling and experimental research of interactions between two anti-hTNF alpha monoclonal antibody variable regions and hTNF alpha].
On SGI workstation, we constructed two anti-hTNF alpha McAbs by means of homologous protein-structure-prediction method. And then, on the basis of relative experimental results and the surface properties of hTNF alpha and two McAbs, we performed the docking of hTNF alpha into two anti-hTNF alpha McAbs. In order to confirm the models, we prepared two hTNF alpha mutants designed according to the binding models, analysed and predicted the possible changes in complexes resulted from hTNF alpha mutations. The experimental analysis results proved these complex models. This will make the base of our next antibody humanization and/or reshape work.
Antibodies, Monoclonal↗
The immunomarker of aging and the modulatory effect of Chinese medicinal herbs on the dysfunction of lymphocytes in the elderly.
PURPOSE: This study examined an immunomarker of aging and evaluated the modulatory effect of Chinese medicinal herbs (CMH) on the immune function of lymphocytes in the elderly. METHODS: Forty-seven elderly and fifteen young persons were selected as study subjects. Peripheral blood lymphocytes (PBL) were isolated by Ficoll-Hypaque gradient centrifugation. The responsive proliferation was investigated by means of the 3H-TdR incorporation procedure. The phenotype and receptor of lymphocytes were measured using indirect immunofluorescence. RESULTS: Both Rg1 and Gy-P significantly increased the responsive proliferation of lymphocytes in the elderly, p < 0.001 and p < 0.05, respectively. Rg1 also had a stimulatory effect on the receptor, CD25, and phenotype, CD45RA, CD45RO, in lymphocytes in aged persons. The immunomarker of aging was established by multiparametric indications on the basis of study at the cellular and molecular levels. CONCLUSION: The possibility exists that a lowered immune function can be reversed with modulation. In the near future, a highly purified, nontoxic, and more effective immunomodulator could be produced from CMH as an antiaging drug.
Adjuvants, Immunologic↗
[Estrogen receptor gene polymorphism and its association with clinicopathological manifestation of lupus nephritis].
OBJECTIVE: To investigate the distribution of estrogen receptor (ER) in patients with lupus nephritis (LN), and the association between ER gene polymorphism and the clinical and pathological features of the disease. METHODS: The Pvu II and Xba I restriction fragment length polymorphism (RFLP) of estrogen receptor gene were analyzed in 245 biopsy proven LN patients (58 males and 187 females) and 172 normal controls(101 males and 71 females) by PCR-RFLP. The clinical and pathological features of 49 male and 152 female LN patients with genotype PpXx or Ppxx, ppxx were then analyzed respectively. RESULTS: It was found that genotype PpXx and ppxx, Ppxx were three major genotypes of ER gene in both lupus patients group and control group. The distribution of ER gene polymorphism was quite different in lupus patients of different genders. The frequency of the PpXx genotype was significantly higher in male LN patients than in both the gender matched normal controls (P<0.05) and the female LN patients (P<0.05), while no difference was shown in the frequency of PpXx genotype between female LN patients and female controls. Interestingly, varied clinical and renal pathological features were also demonstrated in female patients with different genotypes of ER gene. CONCLUSION: The distribution of ER gene polymorphism in LN patients varies with gender. The PpXx genotype of ER gene may be associated with the susceptibility of LN in male. ER gene polymorphism is probably one of the genetic factors contributing to the development of clinical heterogeneity and sexually dimorphic manifestations of LN.
Adolescent↗
Partial hepatectomy and laparoscopic-guided liver biopsy in rhesus macaques (Macaca mulatta): novel approach for study of liver regeneration.
BACKGROUND AND PURPOSE: Although valuable information has been gained using a rodent partial hepatectomy model to assess liver regeneration, the ability to apply this research to humans remains uncertain. Thus, liver regeneration was assessed in a non-human primate, the rhesus macaque (Macaca mulatta). METHODS: One animal underwent 60% hepatectomy, a second animal underwent 30% hepatectomy, and control surgery (cholecystectomy) was performed on two separate animals. Laparoscopic-guided liver biopsy was performed on days 1, 2, 7, 14, and 30 after surgery. Changes in hemoglobin concentration and alanine transaminase activity were assessed, and liver regeneration was evaluated by measuring the expression of Ki-67. RESULTS: All animals survived surgery and laparoscopy. Substantial liver regeneration was induced in the animal that underwent 60% hepatectomy. Excellent tissue specimens were obtained via laparoscopic-assisted liver biopsy. CONCLUSIONS: Sixty percent partial hepatectomy in rhesus macaques appears to be an excellent model for the study of hepatocellular regeneration. The procedure was safe, and effectively induced liver regeneration. In addition, laparoscopic-guided liver biopsy allows observation of changes in the liver remnant as regeneration develops, and provides excellent tissue specimens for analysis. Thus, this rhesus macaque partial hepatectomy model will allow further characterization of liver regeneration in a species closer to humans.
Animals↗
Epileptogenesis after status epilepticus reflects age- and model-dependent plasticity.
Although epilepsy often begins in childhood, factors that contribute to the development of epilepsy as a consequence of status epilepticus (SE) during early development are poorly understood. We investigated animal models in which seizure-induced epileptogenicity could be studied. Rats undergoing self-sustaining SE induced by perforant path stimulation (PPS) at the ages of postnatal day 21 (P21) and P35 were compared with those subjected to SE by lithium and pilocarpine (LiPC). Although only one animal subjected to PPS at P21 developed chronic spontaneous seizures by several months of observation, all the animals subjected to PPS at P35 became epileptic. In the LiPC model, however, most of the rat pups subjected to SE at P21 became epileptic. Animals with spontaneous seizures showed increased inhibition in the dentate gyrus, a characteristic of the epileptic brain, with evidence of mossy fiber synaptic reorganization. Examination of circuit recruitment by c-Jun immunohistochemistry showed activation restricted to the hippocampus in P21 animals subjected to PPS, although extensive activation of hippocampal and extrahippocampal structures was seen in pups subjected to PPS-induced self-sustaining SE at P35 or LiPC SE at P21. These results demonstrate that the appearance of epilepsy as a consequence of SE is influenced by the type of insult as well as by age-dependent circuit recruitment.
Aging↗
Immunologic effects of gliotoxin in rats: mechanisms for prevention of autoimmune diabetes mellitus.
Various fungal products, such as gliotoxin (GT), have immunomodulating activity, a fact exploited previously by our group for prevention of autoimmune diabetes mellitus in BB/Wor rats. To understand better the immunologic effects in GT-treated rats, splenocytes from 65-day-old prediabetic diabetes-prone rats were phenotypically characterized after chronic treatment with GT. A parallel study examined the direct effects of GT on splenocyte preparations incubated with the mycotoxin. In vitro treatment of splenocytes with GT revealed relative decreases in CD4+ and increases in CD8+ T-cell subsets, whereas in vivo treatment with GT did not result in detectable alterations in relative CD4+ and CD8+ cell subsets. We were unable to show significant effects on NK cells or MHC class II cells. However, in vitro and in vivo GT treatments significantly enhanced the detectable RT6 surface marker, a key regulatory element in autoimmune diabetes pathogenesis. This study showed that GT selectively affects certain lymphocyte subsets, possibly through the mechanism of apoptosis, which was increased in vivo as well as in vitro.
ADP Ribose Transferases↗
Characterization of the lipid-binding properties and lipoprotein lipase inhibition of a novel apolipoprotein C-III variant Ala23Thr.
We have identified a G-to-A transition in exon 3 of the APOC3 gene resulting in a novel Ala23Thr apolipoprotein (apo) C-III variant, associated with apoC-III deficiency in three unrelated Yucatan Indians. The Ala23Thr substitution modifies the hydrophobic/hydrophilic repartition of the helical N-terminal peptide and hence could disturb the lipid association. In vitro expression in Escherichia coli of wild-type and mutant apoC-III enabled the characterization of the variant. Compared with wild-type apoC-III-Ala23, the mutant apoC-III-Thr23 showed reduced affinity for dimyristoylphosphatidylcholine (DMPC) multilamellar vesicles with higher amounts of free apoC-III. Displacement of apoE from discoidal apoE:dipalmitoylphosphatidycholine (DPPC) complex by apoC-III-Thr23 was comparable to wild type but the less efficient binding of the apoC-III-Thr23 to the discoidal complex resulted in a higher apoE/apoC-III (mol/mol) ratio (34%) than with wild-type/apoE:DPPC mixtures. The inhibition of lipoprotein lipase (LPL) by apoC-III-Thr23 was comparable to that of wild type, and therefore effects on LPL activity could not explain the lower triglyceride (Tg) levels in Thr-23 carriers. Thus, these in vitro results suggest that in vivo the less efficient lipid binding of apoC-III-Thr23 might lead to a faster catabolism of free apoC-III, reflected in the reduced plasma apoC-III levels identified in Thr-23 carriers, and poorer competition with apoE, which might enhance clearance of Tg-rich lipoproteins and lower plasma Tg levels seen in Thr-23 carriers.
1,2-Dipalmitoylphosphatidylcholine↗
A method for vocabulary development and visualization based on medical language processing and XML.
A comprehensive controlled clinical vocabulary is critical to the effectiveness of many automated clinical systems. Vocabulary development and maintenance is an important aspect of a vocabulary, and should be linked to terms physicians actually use. This paper presents a method to help vocabulary builders capture, visualize, and analyze both compositional and quantitative information related to terms physicians use. The method includes several components: an MLP system, a corpus of relevant reports and a visualization tool based on XML and JAVA.
Humans↗
Effects of sequential pollination on the success of "fast" and "slow" pollen donors in Hibiscus moscheutos (Malvaceae).
Competition among pollen grains for the chance to fertilize ovules typically involves two stages: arrival times on stigmas and/or the growth of pollen tubes through styles. In a previous study of Hibiscus moscheutos, we found that individual pollen donors often differed in pollen tube competitive ability. Here we determined whether short delays in pollen arrival time altered the average success of "fast" and "slow" pollen donors when both types of pollen experienced the same delays. Hand-pollination experiments were carried out using four pairs of pollen donors that differed in competitive ability. We allowed delays of 15 or 30 min between the first and second pollen donor and then determined seed paternity using allozyme markers. The second donor typically sired fewer seeds than pollen that arrived earlier, but, contrary to expectation, "faster" pollen did not always sire significantly more seeds than "slower" pollen when each was applied after delays of the same duration. In two of the four pairs of donors, differences that were seen following simultaneous pollinations disappeared when each type of pollen was applied following identical delays of 15 or 30 min. This unexpected response suggests that the dynamics of pollen tube competition are more complex than anticipated.
Journal Article↗
[Genotyping cytochrome P450IIE1 in alcoholic liver diseases and its significance].
OBJECTIVE: To study the relationship between genotypes of cytochrome P450IIE1 (IIE1 ) and development of chronic liver diseases. METHODS: Cytochrome P450IIE1 was genotyped by PCR and restricted endonucleases digestion of DNA prepared from peripheral white blood cells. RESULTS: IIE1 could be divided into three types: A, B and C based on different products digested by two endonucleases. In normal controls predominant genotypes were A and B. No relationship was found between development of non-alcoholic chronic liver diseases and IIE1 genotypes. Its genotype distribution was similar to normal controls. Detection of type A in alcoholic liver diseases was significantly decreased and type B was significantly increased (P<0.01). Detection of type A in alcohol-related hepatocellular carcinoma was also decreased and type B increased compared to non-alcohol-related hepatocellular carcinoma. CONCLUSION: IIE1 genotypes play some roles in development of alcoholic liver diseases and alcohol-related hepatocellular carcinoma.
Adult↗
[The development and application of a minitype multifunctional bio-impactor].
This study was aimed to develop a device that can be used for gas percussion, rigid impact, cell injury and simple estimation of the condition of injury. The device has been developed with the use of aerodynamical principle, measuring technique for feeble signal, and integration of machine-electricity. The gas percussion, rigid impact, and cell injury can be produced by altering impact tip. It was examined in the experimental researches of eye, brain, lung and cell injury; the parameters of causing injury could be controlled and on-line tested by the computer. The neurological states of pre- and post-injury were evaluated with the device. The results of animal experiments showed that mild, moderate and severe injury models were produced by gas pressure respectively. The pressure was 400, 600, 700 kPa for rats brain gas percussion injury, 600, 800, 1000 kPa for rabbits' retinal contusion, 300, 450, 600 kPa for rats' lung rigid impact injury, and 100, 150, 200 kPa for cultured cells' injury. In conclusion, the device is simple and easy to use for making controllable injury models, in which different parts and levels of injuries on different minitype animals can be reproduced.
Animals↗
Preliminary report on the effect of Nd: YAG laser irradiation on canine tooth pulps.
OBJECTIVE: To study the effects of Nd: YAG laser irradiation on the canine tooth pulps. METHODS: The crown pulp of dog was exposed and excised by ND: YAG laser irradiation. Histopathological examination was used to check changes of the tissues in root canal and periodontium. RESULTS: The pulp of the crown could be successfully excised by Nd: YAG laser without harmful changes in either root canal or periodontal tissues. CONCLUSION: This study may provide an experimental basis for the clinical possibility of crown pulp excision by using Nd: YAG laser irradiation.
Aluminum Silicates↗
[Detection of circulating pemphigus vulgaris antibodies in families of patients with pemphigus vulgaris].
OBJECTIVE: To detect the autoantibodies on 30 first-degree relatives of 12 patients with pemphigus vulgaris (PV), who may share the same susceptible gene with the patients. METHODS: Immunoblot and indirect immunofluorescence (IIF) method were used to detect circulatory PV antibodies in the peripheral blood. RESULTS: PV antibodies were found in 19 of 30 (63%) relatives by both methods, but 10 control serum were all negative by both methods. CONCLUSION: Healthy PV antibody carriers may also exist in high frequency in the first-degree relatives of Chinese PV patients.
Adolescent↗