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Biomedical subjects

J Ling

Publications and source records attributed to J Ling.

At least 73 records · Page 4Linked to original sources
PubMed1997

A liver transplantation technique in a patient with a thrombosed portal vein and a functioning renal-lieno shunt.

A liver transplant technique is described in a patient with a thrombosed portal vein and a functioning surgically created renal-lieno shunt. Permanent portal inflow to the graft was provided by division of the left renal vein (LRV) at its junction with the inferior vena cava and anastomosis of the LRV end-to-end with the donor portal vein. Although this results in splanchnic blood traversing a 360 degree roundabout from the superior mesenteric vein via the splenic and disconnected left renal veins to the donor portal vein, the anastomosis lay well and the procedure was successful.

Anastomosis, Surgical↗
PubMed1996

Factors associated with the intent of firearm-related injuries in pediatric trauma patients.

OBJECTIVE: To examine the characteristics of unintentional and assaultive firearm-related pediatric injuries treated in trauma centers. DESIGN: Comparative analysis of patients 14 years or younger who were admitted to the trauma centers because of unintentional firearm-related injuries (n = 292) vs assaultive firearm-related injuries (n = 457). SETTING: Sixty-eight trauma centers or children's hospitals in the continental United States and Canada that reported data to the National Pediatric Trauma Registry from January 1, 1990, through December 31, 1994. MAIN OUTCOME MEASURES: Frequency distributions of firearm-related injuries in relation to intent and injury circumstances, odds ratios (ORs) on the intent of injury being assaultive, injury severity scales, and in-hospital fatality rates. RESULTS: The frequency of unintentional firearm-related injuries rose in the afternoons peaking between 4 and 5 PM; they predominantly occurred at home (89%). Assaultive firearm-related injuries peaked sharply between 8 and 9 PM and usually occurred on roads or in other public places (63%). About 3 times as many boys as girls were harmed in firearm-related injuries. Given a firearm-related injury resulting in admission to a trauma center, the adjusted OR of it being assaultive was 2.8 (95% confidence interval [CI], 1.6-4.6) if the victim was a girl, 4.9 (95% CI, 3.1-7.8) if the shooting occurred at night, 2.6 (95% CI, 1.6-4.2) if the shooting occurred on a weekday, and 21.1 (95% CI, 9.1-49.4) if the shooting occurred on a road. Injury patterns and severity were similar between patients with unintentional and assaultive injuries. Overall, 19% of the patients sustained head injuries, which contributed to 90% of the in-hospital deaths. CONCLUSIONS: Marked differences in injury circumstances exist between unintentional and assaultive firearm-related injuries among children. The late afternoon hours when many children have come home from school but their parents may still be working have the highest frequency of unintentional firearm-related injuries. The evening peak of assaultive injuries may be related to drug-related and gang-related violence. While it is important to reduce the access of firearms to children, school-based extracurricular and community-based social services should be considered in developing intervention programs.

Adolescent↗
PubMed1996

Cytotoxicity of two new ribosome-inactivating proteins, cinnamomin and camphorin, to carcinoma cells.

Cinnamomin (two-chain) and camphorin (single-chain), two novel ribosome-inactivating proteins (RIPs) purified from the seeds of Cinnamomum camphora, produced inhibitory effects in cultured carcinoma cells. The IC50 of cinnamomin to the human hepatocarcinoma cell-line 7721 and the melanoma cell-line M21 were 18.8 nmol and 11.7 nmol respectively. The IC50 of camphorin to the human hepatocarcinoma cell-line 7721 was 59 nmol, whereas the melanoma cell-line M21 was not susceptible to camphorin. Furthermore, cinnamomin exhibited a remarkable inhibitory effect on the growth of solid melanoma in the skin of the nude mouse. An R-fragment could be isolated from ribosomes of cinnamomin- or camphorin-treated carcinoma cells after incubation with acidic aniline, indicating that the cytotoxicity of these two new RIPs to carcinoma cells might result from modification to the ribosomes.

Algal Proteins↗
PubMed1996

[Immunostaining of mitochondrial heat shock proteins (mtHSPs) in skeletal muscle fibers of mitochondrial cytopathy].

Expression of the mtHSPs (HSP60 and mtHSP70) was immunohistochemicall observed in biopsied limb muscles of genetically determined mitochondrial cytopathies (chronic progressive ophthalmoplegia 14, MELAS 4, limb girdle syndrome with the A-to-G transition at nt.3243 of tRNALeu(UUR), exertional myoglobinuria with multiple deletions of mtDNA 2, and Leber's hereditary optic neuropathy 2). mtHSP 70 and HSP 60 were strongly localized at ragged-red fibers. In strongly succinate dehydrogenase-reactive vessels of MELAS, mtHSP70 was expressed. GRP78 was expressed in the cytoplasmic body, which is often observed in this disorder. The present data suggest that expression of mtHSPs may reflect increased numbers of mitochondria, an impairment of assembly of mitochondrial proteins encoded by the genomic DNA and abnormal mitochondrial DNA, and/or an impaired mitochondrial function due to recurrent oxygen radical attacks against mitochondria.

Chaperonin 60↗
PubMed1996

[Expression of the PAC gene of S. mutans in S. lactis].

Expression of the pac gene in S. lactis were analyzed by dot immunoblotting with rabbit anti-PAc serum. The amount of PAc produced by S. lactis HL107 (pLF107) was measured. This result indicated that a small amount of rPAc was detected in the culture supernatant and cell homogenate of S. lactis HL107 (pLF107) but not in the control strain S. lactis LM0230. The amount of rPAc in S.lacits HL107 (pLF107) was six times lower than that in S. mutans Ingbritt. Expression of cloned pac gene in S. lactis was also confirmed in this result.

Bacterial Proteins↗
PubMed1996

[The characterization of Streptococcus mutans MT8148 and its glucosyltransferase deficient mutants].

The characterization of GTase-deficient mutants of S. mutans MT8148 was analysed to understand the possible virulence of GTase. In the presence of 1% sucrose, these mutants lost the ability to adhere to glass wall and the insoluble glucan synthesis was dramatically decreased. The GTase enzyme activity for insoluble glucan synthesis of these mutants was also decreased. Western blot using anti-CAGTase polyclonal antibody and anti-GTFI or anti-GTFSI monoclonal antibody showed the lack of the corresponding GTase which further confirmed the mutation of specific GTase gene.

Bacterial Adhesion↗
PubMed1995

Simultaneous existence of two types of ribosome-inactivating proteins in the seeds of Cinnamonum camphora--characterization of the enzymatic activities of these cytotoxic proteins.

Two types of ribosome-inactivating proteins (RIPs), camphorin and cinnamomin, have been purified from the seeds of Cinnamomum camphora. Camphorin is a type I RIP with a molecular mass of 23 kDa. Cinnamomin is a type II RIP having three isoforms, its molecular mass is around 61 kDa. The A- and B-chain derived from cinnamomin isoforms have similar mobilities in SDS-polyacrylamide gel. Camphorin and cinnamomin are both glycoproteins. In phylogenesis, it is particularly significant to find the simultaneous existence of type I and type II RIP as well as three isoforms of the latter in the same organ of a higher plant. The molecular mechanism of action of these two RIPs on mammalian ribosomes was demonstrated to be the specific RNA N-glycosidase activity. They modify 28S RNA among the four species of ribosomal RNAs. The cleavage site is the adenosine at position 4324 (rat liver 28S rRNA) embedded in the highly conserved 'R/S domain'. It is the first report that an intact type II RIP (cinnamomin) exhibits RNA N-glycosidase activity. Additionally, camphorin and cinnamomin can cleave supercoiled double-stranded DNA into nicked and linear forms (Ling et al. (1994) FEBS Lett. 345, 143-146).

Algal Proteins↗
PubMed1995

A double mutant of sperm whale myoglobin mimics the structure and function of elephant myoglobin.

The functional, spectral, and structural properties of elephant myoglobin and the L29F/H64Q mutant of sperm whale myoglobin have been compared in detail by conventional kinetic techniques, infrared and resonance Raman spectroscopy, 1H NMR, and x-ray crystallography. There is a striking correspondence between the properties of the naturally occurring elephant protein and those of the sperm whale double mutant, both of which are quite distinct from those of native sperm whale myoglobin and the single H64Q mutant. These results and the recent crystal structure determination by Bisig et al. (Bisig, D. A., Di Iorio, E. E., Diederichs, K., Winterhalter, K. H., and Piontek, K. (1995) J. Biol. Chem. 270, 20754-20762) confirm that a Phe residue is present at position 29 (B10) in elephant myoglobin, and not a Leu residue as is reported in the published amino acid sequence. The single Gln64(E7) substitution lowers oxygen affinity approximately 5-fold and increases the rate of autooxidation 3-fold. These unfavorable effects are reversed by the Phe29(B10) replacement in both elephant myoglobin and the sperm whale double mutant. The latter, genetically engineered protein was originally constructed to be a blood substitute prototype with moderately low O2 affinity, large rate constants, and increased resistance to autooxidation. Thus, the same distal pocket combination that we designed rationally on the basis of proposed mechanisms for ligand binding and autooxidation is also found in nature.

Amino Acid Sequence↗
PubMed1995

Partial restoration of inactivated ribosomes with sodium borohydride or amino acids.

The aldehyde radical of ribose C1' at position 4324 in rat liver 28S rRNA generated by RNA N-glycosidase was either reduced to an hydroxyl group by sodium borohydride or converted into aldimine through a nucleophilic addition of amino acid used as a primary amine. Analysis of the R-fragment of 28S rRNA by polyacrylamide gel electrophoresis showed that the reduction of aldehyde to an hydroxyl group with sodium borohydride was highly specific. The protein synthesis activity of modified ribosomes was partially restored with the removal of the active aldehyde by sodium borohydride or amino acid. Reduction of aldehyde with sodium borohydride restored 43.1% of the protein synthesis activity. Among the twenty natural amino acids tested, tryptophan and histidine could restore 57.4% and 42.1% of the ribosome activity when brome mosaic virus RNA was used as mRNA. We came to the conclusion that the active aldehyde radical at position 4324 of 28S rRNA in modified ribosome may cause the inactivation of the ribosome for protein synthesis.

Algal Proteins↗
PubMed1995

Clinical evaluation of the oscillometric blood pressure monitor in adults and children based on the 1992 AAMI SP-10 standards.

OBJECTIVE AND METHODS: A noninvasive blood pressure monitor (model BP8800MS, Colin Medical Instruments Corp., San Antonio, TX) that uses the oscillometric principle was evaluated against the manual auscultatory method in 85 adults and 85 children following the requirements of the 1992 AAMI SP-10 standard. This was the first evaluation study of the electronic sphygmomanometers according to the new AAMI standards. RESULTS: In adult subjects, the mean difference and standard deviation of the differences between the oscillometric and auscultatory methods were 2.81 +/- 5.35 mm Hg (mean +/- SD) for systolic and 0.04 +/- 4.90 mm Hg for diastolic; in children, they were 3.18 +/- 5.96 mm Hg for systolic and -0.82 +/- 5.24 mm Hg for diastolic. Excellent correlation between the oscillometric and auscultatory methods, particularly the diastolic pressure, is due to usage of the Phase V Korotkoff's sounds for auscultatory detection of the diastolic pressure, increased accuracy of the two observers' measurements, and proper selection of cuff sizes depending on the mid-arm circumference. Five different-sized cuffs were used in this study. The cuff-width-to-midarm circumference ratio was adjusted to be 0.4 or larger to minimize the measurement error associated with mismatch of cuff-size/arm-size relationship. The distribution of errors associated with each cuff was nearly the same. CONCLUSIONS: The 1992 AAMI SP-10 standards offer a thorough evaluation of the oscillometric sphygmomanometer by enforcing more stringent criteria on (1) agreement between two observers, (2) wide spectrum of blood pressure from hypertensive (above 180 mm Hg) to hypotensive, and (3) data analysis. The oscillometric blood pressure monitor evaluated in this study meets the specifications of the new AAMI SP-10 standards and can offer an accurate, automatic, and noninvasive measure of both systolic and diastolic blood pressure in adults and children. It can safely replace the manual or automatic auscultatory system in various clinical settings.

Adolescent↗
PubMed1995

Effect of lithium in immunodeficiency: improved blood cell formation in mice with decreased hematopoiesis as the result of LP-BM5 MuLV infection.

Lithium salts have been demonstrated to induce the production of hematopoietic cells following administration in vivo and to minimize the reduction of these cells following treatment with either radiation, chemotherapeutic or antiviral drugs. We have previously demonstrated that lithium, when administered in vivo to immunodeficient mice infected with LP-BM5 MuLV (MAIDS) significantly reduced the development of lymphadenopathy, splenomegaly, and the lymphoma associated with late-stage immunodeficiency disease in this model, and increased the survival of these animals compared to virus-infected controls not receiving lithium. We report here the results of in vivo studies in the MAIDS model that determined the effect of lithium on peripheral blood indices and the number of myeloid (CFU-GM), erythroid (BFU-E) and megakaryocyte (CFU-Meg) hematopoietic progenitors from bone marrow and spleen harvested from immunodeficient mice receiving lithium carbonate (1 mM) placed in their drinking water compared to virus-infected controls not receiving lithium. Time-points evaluated were at weeks 1, 5, 9, 13, 17, and 21 postviral infection. Virus-control mice not receiving lithium demonstrated all the signs that are characteristic of MAIDS, i.e., splenomegaly, lymphadenopathy, hypergammaglobulinemia, reduced hematopoiesis, and death. Infected mice receiving lithium demonstrated diminished presence of splenomegaly, lymphadenopathy, hypergammaglobulinemia, no suppression of hematopoiesis nor mortality. Enhanced hematopoiesis was demonstrated by neutrophilia, lymphocytosis, thrombocytosis, and erythrocytosis that was evident by increased myeloid, erythroid, and megakaryocyte progenitor cells cultured from bone marrow and spleen. These studies further demonstrate that lithium influences the disease process in the MAIDS model and restricts the development of hematopoietic suppression that develops in this retroviral animal model of immunodeficiency.

Animals↗
PubMed1995

Effect of combination interleukin-3 (IL-3) and granulocyte-macrophage colony stimulating factor (GM-CSF) on hematopoiesis administered to retrovirus-infected immunodeficient mice receiving dose-escalation zidovudine (AZT).

We have previously demonstrated that continuous administration of dose-escalation zidovudine (AZT) in either normal or LP-BM5 MuLV immunodeficient virus-infected mice (MAIDS) was associated with the development of anemia, neutropenia, and thrombocytopenia. Hematopoietic growth factors/cytokines are being evaluated to determine their efficacy in ameliorating the hematopoietic toxicity associated with AZT. In normal mice receiving AZT, an increase in only plasma erythropoietin and not GM-CSF, Meg-CSF or TNF-alpha has been reported. This article describes studies that investigated the effect of combination interleukin-3 (IL-3) and granulocyte-macrophage colony stimulating factor (GM-CSF) administered in normal non-viral, viral-infected, and viral-infected C57BL6 mice receiving dose-escalation AZT, i.e. 0.1 mg/ml, 1.0 mg/ml, and 2.5 mg/ml placed in the drinking water. Non-viral control mice responded to IL-3/GM-CSF by increasing erythropoiesis, myelopoiesis and platelet production measured by increased bone marrow and spleen derived erythroid, myeloid and platelet precursor stem cells cultured in semi-solid media. Virus-infected control mice not receiving IL-3/GM-CSF developed pancytopenia. Administration of IL-3/GM-CSF to virus-infected mice receiving dose-escalation AZT did not ameliorate the peripheral pancytopenia associated with immunodeficiency disease and AZT treatment, even though erythroid, myeloid and platelet precursor progenitor cells were increased at certain times when compared to either normal or viral-infected mice receiving IL-3/GM-CSF. These results indicate that the combination use of IL-3 and GM-CSF in vivo is only a partially effective growth factor/cytokine treatment to ameliorate the hematopoietic toxicity associated with the use of the anti-viral drug zidovudine.

Animals↗
PubMed1995

Topological requirements for recognition and cleavage of DNA by ribosome-inactivating proteins.

Ribosome-inactivating proteins (RIPs) were demonstrated to exhibit a unique enzymatic activity on cleaving supercoiled double-stranded DNA into the nicked or linear form. Although there is an interaction between supercoiled DNA and RIP, no sequence-specific recognition was involved. Instead, RIPs recognize supercoiled DNA by conformational specificity. Negatively supercoiled DNA is the preferential conformation in the action of RIPs. When double-stranded DNA occurs in the supercoiled form, even if with lower linking number, RIPs can still convert it into nicked or linear form. Terminal-labelling experiments indicated that radioactivity was incorporated into putative 5'-ends of nicked or linear DNA generated by RIPs. We conclude that RIPs act as a novel supercoil-dependent endonuclease when they cleavage supercoiled DNA. The impossibility that contaminating enzymes in the RIP preparations cleaved the supercoiled DNA is briefly discussed.

Algal Proteins↗
PubMed1995

Nutritional assessment with bioelectrical impedance analysis in maintenance hemodialysis patients.

Protein energy malnutrition is common among persons with ESRD and contributes substantially to morbidity and mortality. The usual methods of nutritional assessment, such as anthropometry, can be misleading because of altered tissue hydration. Bioelectrical impedance analysis (BIA) has been recommended by some as a practical nutritional assessment tool but has not been validated in patients with ESRD. Thirty-three stable patients on maintenance hemodialysis were evaluated in an ambulatory clinical research center with simultaneous BIA, dual-energy x-ray absorptiometry, and deuterium oxide (D2O) and sodium bromide (NaBr) isotope dilution studies. Standard determinations of total body water (TBW) and body cell mass (BCM) were obtained and compared with values estimated by BIA. Two separate outpatient BIA measurements were also obtained approximately 2 wk before and after the clinical research center evaluation. BCM estimated by BIA was directly correlated (r = 0.92, P < 0.0001) with BCM determined by DEXA and NaBr. TBW estimated by BIA was directly correlated (r = 0.96, P < 0.0001) with TBW determined by deuterium oxide dilution. The reactance to resistance ratio (Xc/R) derived from BIA was inversely correlated (r = -0.73, P < 0.0001) with the extracellular water/TBW ratio determined by NaBr/D2O. Bland-Altman analyses showed that for TBW, BIA was in excellent agreement with D2O dilution. BCM was modestly underestimated by BIA compared with the dual-energy x-ray absorptiometry/NaBr standard and was adjusted by linear regression. The coefficients of variation on repeated BIA measurements were below 4%, demonstrating test-retest reliability. BIA is a valid and reliable method of nutritional assessment in maintenance hemodialysis patients.

Absorptiometry, Photon↗
PubMed1995

Ultrastructural changes of chondrocytes of growth plates of young broiler chickens predisposed to tibial dyschondroplasia.

Growth plates from the proximal tibiotarsal bones of growing broiler chickens from lines exhibiting high and low incidences of tibial dyschondroplasia (TD) were compared for ultrastructural differences. Samples of growth plates were collected from five chickens of each line at 2, 7, 14, and 21 d of age. Each sample was prepared for ultrastructural evaluation after initial fixation in 2.5% glutaraldehyde and secondary fixation in 1% osmium tetroxide, each containing .7% ruthenium hexamine trichloride. No gross TD lesions were observed. The ultrastructure of growth plates of birds at 2, 7, and 14 d of age was similar between the groups. However, at 21 d of age, chondrocytes in the prehypertrophic zone of the high incidence group contained large lipid inclusions and vesiculated and disarranged stacks of rough endoplasmic reticulum with greatly dilated cisternae. Apoptotic and necrotic chondrocytes were present in the hypertrophic zone. Nuclei of apoptotic chondrocytes contained crescentic caps of condensed chromatin. The cytoplasm contained short segments of dilated granular endoplasmic reticulum, lipid droplets, and vacuoles. Necrotic chondrocytes appeared as amorphous masses with pyknotic and karyorrhectic nuclei. These changes were not observed in chondrocytes of the low TD incidence group and have not been previously reported in nonthickened growth plate cartilage.

Animals↗