Biomedical subjects
Publications and source records attributed to S Zhu.
The changes of HSP70 and NF after brain contusion were studied by the immunohistochemistry method. HSP70 and NF were seen at 30 min after injury around the wound area, but faded away after 12-24 h. The result suggests that these two proteins could be used to estimate brain contusion time, to diagnose brain wound and to distinguish antemortem and postmortem brain contusion.
OBJECTIVE: To evaluate the effects of high-frequency color ultrasonography on diagnosis of parotid tumors. METHODS: 36 cases of parotid benign or malignant tumors were observed from margin to inner with color Doppler flow imaging (CDFI) and color Doppler energy (CDE) according to tumors' two dimention. RESULTS: The features of benign tumors included round or round-like shapes, clear margins and inner balanced echogram. The margin feature of CDFI was star-like images, and the peak systolic celocity was up to 18.6 and 16.2 cm/s. The coincidence of diagnosis was 90%. Meanwhile, the shapes of malignant tumors showed irregular and incomplete mass and asymmetrical inner echogram. The primary characteristics of CDFI were branch-like or basket-like images, and the peak systolic velocity was much higher (35.2 and 32.4 cm/s) than that of benign tumors. There was significant difference between these two groups (P < 0.05). It indicated richer flow signals in CDE than in CDFI. CONCLUSION: CDFI and CDE show an important clinical value in diagnosing parotid neoplasm.
OBJECTIVE: To investigate the cold preservation effect of rat livers by modified storage method with self-made HYD solution. METHODS: The modified method was that the vascular bed of rat livers was expanded with an additional 20 to 40ml self-made HYD solution/100g liver. After removing the liver, the extra HYD solution expressed as % liver weight was entrapped via portal infusion by tying off the supra-and infra hepatic inferior vena cava. According to the amount of extra HYD solution, 40 rats were randomly divided into four groups including: control group with conventional storage method, 20% group, 30% group and 40% group. The preservation effect of modified storage method with that of conventional storage method by using isolated perfused rat liver model was compared. RESULTS: Bile production and all the indices of hepatic microcirculation including portal perfusion pressure, endothelin-1 in the effluent, trypan blue distribution time and histology in modified method groups were significantly superior to those in control group (P < 0.05). The liver enzymes in 30% group were markedly lower than those in control group (P < 0.05). The preservation effect of rat liver in 30% group was the best among the modified method groups. CONCLUSION: The modified cold stage method is effective and may have potential for clinical application for liver preservation.
Fcgamma-receptors (FcgammaR) provide a critical link between humoral and cellular immunity. The genes of the low-affinity receptors for IgG and their isoforms, namely, FcgammaRIIa, FcgammaRIIb, FcgammaRIIIa, FcgammaRIIIb, and SH-FcgammaRIIIb, are located in close proximity on chromosome 1q22. Variant alleles may differ in biologic activity and a number of studies have reported the frequencies of variant FcgammaR alleles in both disease and control populations. No large study has evaluated the possibility of a nonrandom distribution of variant genotypes. We analyzed 395 normal individuals (172 African Americans [AA] and 223 Caucasians [CA]) at the following loci: FcgammaRIIa, FcgammaRIIIa, and FcgammaRIIIb, including the SH-FcgammaRIIIb. The genotypic distributions of FcgammaRIIa, FcgammaRIIIa, and FcgammaRIIIb conform to the Hardy-Weinberg law in each group. There was no strong evidence that combinations of 2-locus genotypes of the 3 loci deviated from random distributions in these healthy control populations. The distribution of SH-FcgammaRIIIb is underrepresented in CA compared with AA (P < .0001) controls. A previously reported variant FcgammaRIIb was not detected in 70 normal individuals, indicating that this allele, if it exists, is very rare (<1%). In conclusion, we present data that should serve as the foundation for the interpretation of association studies involving multiple variant alleles of the low-affinity FcgammaR.
Five full-length cDNAs encoding the precursors of two 'short chain' scorpion non-toxic peptides active on Ca(2+)-activated K(+) channels (BmP02 and BmP03) and two novel putative long chain K(+) channel-blocking peptides (named BmTXKbeta and BmTXKbeta2) were first isolated from the venom gland cDNA library of the Chinese scorpion Buthus martensii Karsch (BmK). BmTXKbeta2 showed a high similarity with AaTXKbeta, while BmTXKbeta was completely different in the deduced primary structure from the long chain and short chain scorpion toxins already characterized. Thus, BmTXKbeta expands the scorpion long chain K(+) channel-blocking peptide family. Although little sequence similarity exists between the above two short and two long peptides, they are similar at the positions of six cysteines, suggesting that they should all share a similar scaffold composed of an alpha-helix and a three-stranded beta-sheet.
An ionic-type phononic crystal composed of two ferroelectric media with opposite spontaneous polarization aligned periodically in a superlattice structure was studied theoretically and experimentally. The coupling between vibrations of the superlattice and the electromagnetic waves results in various long-wavelength optical properties, such as microwave absorption, dielectric abnormality, and polariton excitation, that exist originally in ionic crystals. The results show that this artificial crystal structure can be used to simulate the microscopic physical processes in real crystals.
Due to the greater range of lengths available to the third complementarity determining region of the heavy chain (HCDR3), the Ab repertoire of normal adults includes larger Ag binding site structures than those seen in first and second trimester fetal tissues. Transition to a steady state range of HCDR3 lengths is not complete until the infant reaches 2 mo of age. Fetal constraints on length begin with a genetic predilection for use of short DH (D7-27 or DQ52) gene segments and against use of long DH (e.g., D3 or DXP) and JH (JH6) gene segments in both fetal liver and fetal bone marrow. Further control of length is achieved through DH-specific limitations in N addition, with D7-27 DJ joins including extensive N addition and D3-containing DJ joins showing a paucity of N addition. DH-specific constraints on N addition are no longer apparent in adult bone marrow. Superimposed upon these genetic mechanisms to control length is a process of somatic selection that appears to ensure expression of a restricted range of HCDR3 lengths in both fetus and adult. B cells that express Abs of an "inappropriate" length appear to be eliminated when they first display IgM on their cell surface. Control of N addition appears aberrant in X-linked agammaglobulinemia, which may exacerbate the block in B cell development seen in this disease. Restriction of the fetal repertoire appears to be an active process, forcing limits on the diversity, and hence range of Ab specificities, available to the young.
Head-up tilt-table test is valuable in diagnosing type of syncope. Sensitivity varies in reports and is mostly poor. Isoproterenol or nitroglycerin is regularly used to increase head-up tilt-table test sensitivity. The aim of this study was to assess the value of sublingual isosorbide dinitrate administration before isoproterenol tilt test as a simple, practical test for diagnosis of neurally mediated syncope. Ninety-six patients (45 men and 51 women, mean age 42.5 years) with recurrent (median 4 times) loss of consciousness that remained unexplained after clinical and noninvasive assessment and 72 healthy volunteers (36 men and 36 women, mean age 40.1 years) were randomly divided into groups: isosorbide-isoproterenol test and isoproterenol test. During isosorbide-isoproterenol test, a positive response (syncope in association with sudden hypotension or bradycardia) occurred in 35 patients (72.9%) with unexplained syncope, an exaggerated response (minor symptoms in association with slowly increasing hypotension alone) occurred in 7 (14.6%), a negative response in 2 (4.2%), and drug intolerance in 4 (8.3%). During isoproterenol testing, these percentages were 52.1%, 16.7%, 25.0%, and 6.2%, respectively. Only 3 control volunteers (8.3%) had a positive response to isosorbide-isoproterenol test and 2 (5.6%) to isoproterenol test. The duration of the test and the time for syncope induction in the isosorbide-isoproterenol test were shorter than those in the isoproterenol test (24.84 +/- 5.15 vs 35.70 +/- 6.28 minutes [p <0.01]; 4.53 +/- 2.86 vs 6.27 +/- 4.11 minutes [p <0.05]). This study concluded that isosorbide-isoproterenol test could be valuable in diagnosing unexplained syncope for its high sensitivity, powerful specificity, and short duration.
BACKGROUND: The mechanism(s) involved in acute cellular xenograft rejection have hitherto been generated in vitro or in different experimental models, with pig tissue being transplanted to rodents. There is an urgent need to validate these results in a clinically more relevant combination of species. METHODS: Fetal porcine islet-like cell clusters (ICC) were transplanted under the kidney capsule in cynomolgus monkeys, either untreated or given immunosuppression with cyclosporine (CsA; 10 mg/kg body weight, intramuscularly) and 15-deoxyspergualin (DSG; 5 mg/kg body weight, intramuscularly). ICC xenografts were examined at 1, 3, 6, or 10-12 days after transplantation, using immunohistochemical techniques. Serum levels of xenoreactive antibodies were measured with ELISA. RESULTS: No deposits of IgM, IgG, Clq, or C3 were detected within the ICC xenograft in any of the monkeys. Likewise, no significant increase in the levels of xenoreactive antibodies were found after transplantation. In untreated animals, a few N-Elastase-positive cells (neutrophil granulocytes) were seen in the xenograft at day 1. A few mononuclear cells were present in the adjacent renal parenchyma, but they did not infiltrate the xenograft. At this time (day 1), early signs of necrosis were observed in the central parts of the graft. On day 3, the graft had a large, central necrotic area that contained polymorphonuclear cells; the remaining parts of the xenograft showed severe infiltration with CD8+ T cells. Occasional CD68+ cells (macrophages) were seen on days 1 and 3. On day 6, large numbers of macrophages were found infiltrating the entire graft. A few CD20+ B cells, accumulated as small clusters, were also found. Only a few natural killer cells (CD56+) were detected. The CsA/DSG-treated monkeys showed markedly fewer CD2+/CD8+ T cells on day 6 than the untreated monkeys, and the ICC graft was clearly better preserved. However, the number of CD8+ and CD68+ cells had increased considerably at 12 days after transplantation and diffusely infiltrated the whole ICC xenograft. CONCLUSION: Porcine ICC transplanted under the kidney capsule in cynomolgus monkeys were rejected by an acute cell-mediated rejection progressing during the first 6 days after transplantation. The process was not dependent on host Ig or C3 binding to the graft. Although the rejection of porcine ICC was significantly delayed in CsA/DSG-treated monkeys, the ICC xenografts were almost completely destroyed 12 days after transplantation.
The expression of p16 gene in normal salivary acini, benign tumors and carcinomas were microscopically and quantitatively observed by using immunohistochemical method LSAB and CMIASWIN methods. The expression of p16 gene were found in all 3 groups. The positive unit (PU) was higher in tumor group and cancer group than that in normal group (P < 0.01). Furthermore, the PU of p16 was stronger in cytoplasm than in nucleus. Malignant tumors and acini surrounding the tumor revealed strong positives and weak positives respectively. The PU of p16 gene was higher in deep lobe of recurrent parotid neoplasm with incomplete capsule than that in shallow lobe of primary parotid neoplasm with complete capsule. The findings suggests that p16 gene plays an equally important role in the salivary gland tumors and tumors in other part of the body.
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Chromosomal normality and sex were diagnosed in each blastomere of bovine embryos derived from in vitro fertilization (IVF). Bovine embryos developing to the 5- to 10-cell stage were separated into individual blastomeres with 0.5% protease. After treatment with 100 ng/mL vinblastine sulfate for 8 to 10 h, they were prepared for chromosome samples. In total, 33 bovine embryos and 185 blastomeres were examined. Chromosomal normality was analyzed in 43.8% (81/185) of the blastomeres and 60.6% (20/33) of the embryos; while chromosomal anomalies were found in 16 (80%, 16/20) of the embryos, 5 haploid embryos and 11 mosaic (n/2n) embryos. Mosaicism characteristic of the opposite sex in X-and Y-chromosomes was found in 2 haploid embryos, and that of a Y-chromosome and of XX chromosomes in 1 n/2n embryo. Various sex-chromosome compositions were also observed in the other 10 chromosomal mosaic n/2n embryos.
The synthesis of four mononuclear palladium complexes of general formula [Pd(en)Cl(L)]NO3 (en = ethylenediamine; L = pyridine (I), 4-methylpyridine (II), 4-hydroxypyridine (III) or 4-aminopyridine (IV) has been achieved. The structure of these compounds was studied by elemental analysis, IR, far-IR and 1H NMR; complex I was analyzed by X-ray diffraction. The crystal of [Pd(en)(pyridine)Cl]NO3 is monoclinic, space group P21/c (a = 7.990(2), b = 16.058(3), c = 9.846(2) A, beta = 103.81(3) degrees, Z = 4, R = 0.067, Rw = 0.066). The Pd(II) atom exhibits an approximately square planar coordination with bond lengths in the range 2.017-2.042 A for Pd-N and 2.320 A for Pd-Cl. In order to determine the donor strength of the aromatic pyridine ligands, the stability constants of binary complex ML2+ (M = [Pd(en) (H2O)2]2+; L = pyridine, 4-Me-pyridine, 4-OH-pyridine and 4-NH2-pyridine) were determined by potentiometric pH titration in aqueous solution (T = 25 degrees C, I = 0.1 mol l-1 NaNO3). The results show that the stability constants of the binary complexes systematically increase with increasing pKa of the pyridines. The above four palladium complexes, [Pt(en)(pyridine)Cl]NO3 and cis-diamminedichloroplatinum (II) (cis-DDP) were assayed for cytotoxicity in vitro against the human leukemia cell line HL-60, and compounds I, II, III and cis-DDP show significant cytotoxic activity against HL-60.
OBJECTIVE: A systematic retrospective study of the largest randomized trial of induction chemotherapy and radiation for advanced laryngeal cancer was undertaken to determine whether specific tumor or biologic factors were predictive of chemotherapy response, organ preservation, or survival. METHODS: The variables analyzed included clinical and histologic factors, immunohistochemical expression of proliferating cell nuclear antigen and p53, and adjusted DNA index measurements. Variables were evaluated for correlation with outcomes of tumor response, organ preservation, and survival. RESULTS: Multivariate analysis revealed that the best predictor of complete response to induction chemotherapy was low T class. The full multivariate model for predicting larynx preservation in patients treated with induction chemotherapy plus radiation shows that T class, p53 overexpression, and elevated proliferating cell nuclear antigen index were independent predictors of successful organ preservation. CONCLUSIONS: These predictive markers should be included in future clinical trials of advanced laryngeal cancer to determine their usefulness prospectively.
We have developed a cell-free system that can trigger the nuclei purified from mouse liver and suspension-cultured carrot cells to undergo apoptosis as defined by the formation of apoptotic bodies and nucleosomal DNA fragments. The effects of different divalent cations and cycloheximide on DNA cleavage in this system were assessed. The fact that nuclei of plant cells can be induced to undergo apoptosis in a cell-free animal system suggests that animals and plants share a common signal transduction pathway triggering in the initiation stage of apoptosis.
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Spontaneous cerebrospinal fluid rhinorrhoea is a clinical entity that is difficult to both diagnose and treat. A case in a 56-year-old woman with a defect in the lateral wall of the sphenoid sinus and middle cranial fossa floor is presented. Pathogenesis and management of this rare condition are discussed. Copyright 1999 Harcourt Publishers Ltd.
A murine phage antibody library containing 1.7 x 10(8) independent clones was constructed and then screened by affinity panning of anti-ricin antibody fragments. First, mRNA was purified from the total RNA extracted from fresh spleens of nonimmunized mice of Kunming, and then the total antibody variable region cDNA was amplified via reverse transcription-polymerase chain reaction. Gene fragments encoding VH and VL were amplified and assembled into a single gene by using a DNA linker encoding a pentadecapeptide (Gly4Ser)3 through primary PCR. Finally the recombinant DNA fragments were cloned into the phagemid pCANTAB 5E vector and electroporated into Escherichia coli TG1. The recombinant phage particles displaying functional single-chain fragment variable regions (scFvs) were rescued by reinfection of helper phage M13KO7, thus constructing a murine antibody library. Two ricin-specific scFvs strains were selected from the phage antibody library by using affinity panning. The target antigen, ricin, was biotinylated with photobiotin and the biotin-labeled ricin interacted with the phage antibody library. Subsequent addition of streptavidincoated paramagnetic beads isolated the biotinylated ricin-binding phage particle complex. Washing, elution, and reinfection of the isolated complex then proceeded sequentially. After six rounds of panning, 2 strains of the 34 clones were verified to show greater specific affinity to ricin.