Elimination of the class A scavenger receptor does not affect amyloid plaque formation or neurodegeneration in transgenic mice expressing human amyloid protein precursors

The class A scavenger receptor (SR) is expressed on reactive microglia surrounding cerebral amyloid plaques in Alzheimer's disease (AD). Interactions between the SR and amyloid beta peptides (Abeta) in microglial cultures elicit phagocytosis of Abeta aggregates and release of neurotoxins. To assess the role of the SR in amyloid clearance and Abeta-associated neurodegeneration in vivo, we used the platelet-derived growth factor promoter to express human amyloid protein precursors (hAPPs) in neurons of transgenic mice. With increasing age, hAPP mice develop AD-like amyloid plaques. We bred heterozygous hAPP (hAPP(+/-)) mice that were wild type for SR (SR(+/+)) with SR knockout (SR(-/-)) mice. Crosses among the resulting hAPP(+/-)SR(+/-) offspring yielded hAPP(+/-) and hAPP(-/-) littermates that were SR(+/+) or SR(-/-). These second-generation mice were analyzed at 6 and 12 months of age for extent of cerebral amyloid deposition and loss of synaptophysin-immunoreactive presynaptic terminals. hAPP(-/-)SR(-/-) mice showed no lack of SR expression, plaque formation, or synaptic degeneration, indicating that lack of SR expression does not result in significant accumulation of endogenous amyloidogenic or neurotoxic factors. In hAPP(+/-) mice, ablation of SR expression did not alter number, extent, distribution, or age-dependent accumulation of plaques; nor did it affect synaptic degeneration. Our results do not support a critical pathogenic role for microglial SR expression in neurodegenerative alterations associated with cerebral beta amyloidosis.

Partial left ventriculectomy for the treatment of end-stage dilated cardiomyopathy

OBJECTIVE

To report our initial experience of the first 5 cases of partial left ventriculectomy (PLV or Batista operation), a new surgical therapy for treatment of end-stage dilated cardiomyopathy in China.

METHODS

From April to August 1998, 5 patients with idiopathic dilated cardiomyopathy received PLV at Anzhen Hospital. The mean age of the patients was 48.4 years (range: 42 to 53 years). Three patients were in New York Heart Association (NYHA) class III and 2 in class IV. All patients had mitral valve insufficiency (3 moderate and 2 severe) and 1 had severe tricuspid valve insufficiency in addition preoperatively. Cardiopulmonary bypass and cardiac arrest with cold blood cardioplegia were used in all patients. The average weight of the resected left ventricle muscle was 46.3 g. All patients underwent mitral annuloplasty and 1 plus tricuspid annuloplasty (De Vega).

RESULTS

Echocardiography demonstrated a significant decrease in left ventricular diastolic diameter (8.4 +/- 1.1 cm to 5.4 +/- 0.4 cm, P < 0.01) and an increase in ejection fraction (17.78% +/- 6.26% to 34.82% +/- 3.18%, P < 0.025). One patient died of heart failure on the 6th postoperative day. The mean follow-up period of the 4 discharged patients were 4 months (from 3 to 6 months). One were in NYHA class I and 3 in class II; all had a normal life.

CONCLUSION

Batista operation is a new and valuable alternative of the surgical treatment for end-stage dilated cardiomyopathy and the long-term results need further studies.

Identification of nuclear orphan receptors as regulators of expression of a neurotransmitter receptor gene

Nuclear orphan receptors are known to be important mediators of neurogenesis, but the target genes of these transcription factors in the vertebrate nervous system remain largely undefined. We have previously shown that a 500-base pair fragment in the first intron of the GRIK5 gene, which encodes the kainate-preferring glutamate receptor subunit KA2, down-regulates gene expression. In our present studies, mutation of an 11-base pair element within this fragment resulted in a loss of nuclear protein binding and reverses negative regulation by the intron. Using yeast one-hybrid screening, we have identified intron-binding proteins from rat brain as COUP-TFI, EAR2, and NURR1. Gel shift studies with postnatal day 2 rat brain extract indicate the presence of COUP-TFs, EAR2, and NURR1 in the DNA-protein complex. Competition assays with GRIK5-binding site mutations show that the recombinant clones exhibit differential binding characteristics and suggest that the DNA-protein complex from postnatal day 2 rat brain may consist primarily of EAR2. The DNA binding activity was also observed to be enriched in rat neural tissue and developmentally regulated. Co-transfection assays showed that recombinant nuclear orphan receptors function as transcriptional repressors in both CV1 cells and rat CG4 oligodendrocyte cells. Direct interaction of the orphan receptors with and relief of repression by TFIIB indicate likely role(s) in active and/or transrepression. Our findings are thus consistent with the notion that multiple nuclear orphan receptors can regulate the transcription of a widely expressed neurotransmitter receptor gene by binding a common element in an intron and directly modulating the activity of the transcription machinery.

Isolation, purification, and characterization of pregnancy-specific protein B from elk and moose placenta

Pregnancy-specific protein B (PSPB) was isolated, purified, and partially characterized from elk and moose placenta. The procedure, which was monitored by bovine PSPB (bPSPB) RIA, included homogenization and extraction in aqueous solution, acidic and ammonium sulfate precipitation, and ion exchange, gel filtration, and affinity chromatographies. The estimated molecular sizes of moose PSPB (mPSPB) were 58 kDa and 31 kDa, and of elk PSPB (ePSPB) were 57 kDa, 45 kDa, and 31 kDa by SDS-PAGE. The isoelectric points of mPSPB were 4.8, 6.6, and 6.7, and of ePSPB were 4.8, 4.9, 6.1, and 6.2 as determined by isoelectric focusing and two-dimensional gel electrophoresis. The carbohydrate contents of mPSPB and ePSPB were approximately 3.15% and 4.98%, respectively. Although ePSPB and mPSPB were recognized by anti-bPSPB in an Ouchterlony double immunodiffusion test, they were found to share identical epitopes and partial identities compared to bPSPB. After treatment at different temperatures (20-60 degrees C) for 1 h, the immunoreactivities of ePSPB and mPSPB in serum were very stable. Only ePSPB in serum treated at 60 degrees C lost some immunoreactivity. After alteration of serum pH (pH 3-11) for 2 h, the immunoreactivities of ePSPB and mPSPB became lower at pH 3 and 4, and remained stable from pH 5 to 11. These data show that moose and elk PSPB have properties similar to those of bovine and ovine PSPB.

[Expression patterns of platelet membrane glycoprotein in healthy adults]

OBJECTIVE

To study the expression patterns of 6 kinds of platelet membrane glycoprotein(GP) in resting and activated platelets of healthy adults.

METHODS

The molecule numbers of platelet GPIIIa, IIb/IIIa, Ib, IX, V and P-selectin on resting platelets or platelets activated by thrombin receptor activating peptide (TRAP) in 60 healthy adults (male/female = 1/1) were detected by flow cytometry.

RESULTS

The expression of GPIIb/IIIa and GPIIIa seemed to decrease with the increase of age in the resting and activated platelets of males. The coefficients of correlation(r) in resting platelets were -0.409 and -0.534 (P < 0.05), respectively; whereas this phenomenon were not found in females. The expression of GPIb was reduced while the expressions of GPIIb/IIIa, IIIa, P-selectin increased after the platelets were activated by TRAP. There was a negative relationship between resting and activated platelets in the expression of P-selectin. The molecule number of GPIb on the surface of resting platelet was about 30,000, the ratio of GPIb to GPV was 3:1.

CONCLUSION

It seems that there exists some difference with age and sex in the expression of platelet membrane glycoproteins in healthy persons.

Determination of the heavy metal binding capacity of aquatic samples using MetPLATE: a preliminary study

MetPLATE, a microbial toxicity test which is specific for heavy metal toxicity, was used to rapidly determine the heavy metal binding capacity (HMBC) of a wide range of surface waters from Florida and Georgia. HMBC determines the impact of physicochemical factors on metal bioavailability and toxicity. The new developed protocol, using MetPLATE as the toxicity assay, showed that HMBC varied from 1.7 to 39.2 for Cd whereas the ranges for Cu and Ag were < 1-11.9 and < 1-2.1, respectively. The effect of seasons on HMBC was determined using samples from the Hogtown Creek, Gainesville, FL, and from the St John's river in Jacksonville, FL. Both surface waters displayed the highest HMBC during the Fall season. Preliminary examination of the limited data set confirms that HMBC may be influenced by the concentration of dissolved organic carbon (DOC). These preliminary data show that the impact of physical and chemical parameters on the toxicity of metals in aquatic environments can be rapidly assessed using rapid and low-cost microbiotests.

Differentiation induction subtraction hybridization (DISH): a strategy for cloning genes displaying differential expression during growth arrest and terminal differentiation

Human cancers often display aberrant patterns of differentiation. By appropriate chemical manipulation, specific human cancers, such as human melanoma, leukemia and neuroblastoma, can be induced to lose growth potential irreversibly and terminally differentiate. Treatment of HO-1 human melanoma cells with a combination of recombinant human fibroblast interferon (IFN-beta) and the antileukemic compound mezerein (MEZ) results in irreversible growth arrest, a suppression in tumorigenic properties and terminal cell differentiation. A potential mechanism underlying these profound changes in cancer cell physiology is the activation of genes that can suppress the cancer phenotype and/or the inactivation of genes that promote the cancer state. To define the repertoire of genes modulated as a consequence of induction of growth arrest and terminal differentiation in human melanoma cells, we are using a differentiation induction subtraction hybridization (DISH) approach. A subtracted cDNA library, differentiation inducer treated cDNAs minus uninduced cDNAs, was constructed that uses temporally spaced mRNAs isolated from HO-1 cells treated with IFN-beta+MEZ. Approximately 400 random clones were isolated from the subtracted DISH library and analyzed by reverse Northern and Northern blotting approaches. These strategies resulted in the identification and cloning of both 30 known and 26 novel cDNAs displaying elevated expression in human melanoma cells induced to growth arrest and terminally differentiate by treatment with IFN-beta+MEZ. The DISH scheme and the genes presently identified using this approach should provide a framework for delineating the molecular basis of growth regulation, expression of the transformed phenotype and differentiation in melanoma and other cancers.

The histiocytoses of infancy

The histiocytoses comprise a rare and incompletely understood group of diseases that are characterized by an abnormal proliferation of histiocytes, mononuclear phagocytic, and antigen-presenting cells belonging to the reticuloendothelial system. The two major types of histiocytoses, which often present during infancy and require significant medical attention, are Langerhans cell histiocytosis and primary hemophagocytic lymphohistiocytosis. Their clinical manifestations frequently overlap, complicating their distinction, but a prompt and accurate diagnosis is essential to deliver the optimal treatment and maximize the chances for a favorable outcome. For Langerhans cell histiocytosis, careful risk stratification is critical for the appropriate administration of therapy. Patients with good prognostic factors may need only observation as their disease spontaneously regresses or minimal intervention. Poor prognostic factors mandate more intensive treatment. Patients with primary hemophagocytic lymphohistiocytosis require chemotherapeutic induction of their disease into a state of remission followed by stem cell transplantation, which currently offers the only known cure. Improvements on current therapies for the histiocytoses will depend on continued advances in the understanding of these enigmatic diseases.

The behaviors of Ca(2+)-ATPase embedded in interdigitated bilayer

We investigated the behavior of a membrane protein, Ca(2+)-ATPase, in interdigitated phospholipid bilayers. The results showed that Ca(2+)-ATPase does not cause significant alterations in the interdigitation of 16:0 LPC/DPPC (27.0 mol% LPC) vesicles when it is reconstituted with lipids. Intrinsic fluorescence, acrylodan fluorescent adducts, and CD spectra indicated that Ca(2+)-ATPase, when embedded in interdigitated bilayer structures, is more exposed to the hydrophilic environment and has a looser structure than when embedded in non-interdigitated bilayers. The interdigitation of acyl chains induces a rapid loss of enzyme activity. It is suggested that interdigitated bilayer structures may play an important role as negative regulatory factors in physiological functions.

[Separation and determination of morphine, pethidine and diazepam by high performance liquid chromatography]

Morphine, penthidine and diazepam in blood were determined by high performance liquid chromatography (HPLC). The HPLC system was consisted of 10 microns particle size C18 column and UV detector set at 254 nm. The mobile phase was V(CH3OH):V(25 mmol/L KH2PO4) = 90:10 with a flow rate of 1.0 mL/min. The average recoveries of morphine, penthidine and diazepam were 93.27%, 90.23% and 93.29% respectively. The linear range was between 0.05-50 mg/L. The detection limit was 0.05 mg/L and CV was less than 6%.

[Expression of interleukin-6 and its receptors in peripheral blood of patients with systemic lupus erythematosus]

OBJECTIVE

To investigate the level of interleukin-6 (IL-6) and soluble-IL-6 receptor (sIL-6R) in serum of patients with systemic lupus erythematosus (SLE) and its correlation with disease activity and to explore IL-6 signal transduction pathways in SLE patients.

METHODS

By using MTT colorimetry and ELISA, the levels of IL-6 and sIL-6R in serum from 16 patients with SLE (9 active, 7 inactive), 17 with active rheumatoid arthritis (RA) and 29 controls were measured. The expressions of acute phase reaction factor (APRF) in peripheral blood mononuclear cells (PBMCs) were also detected by using electrophoresis mobility shift assays (EMSA) after the PBMCs were isolated and then stimulated by IL-6.

RESULTS

Serum IL-6 and sIL-6R levels in active SLE patients were significantly higher than those in normal controls (P < 0.01), but were significantly lower than those in active RA patients (P < 0.01). Serum IL-6 rather than sIL-6R level in active SLE patients was significantly higher than that in inactive ones (P < 0.01). Serum IL-6 was correlated positively with the anti-dsDNA antibody (r = 0.658, P < 0.01), but not with CRP (r = 0.041, P > 0.05). There were no expression of APRF in PMNC from SLE patients and 8 normal controls, whereas PMNC from 11 RA patients expressed APRF activity (11/17).

CONCLUSION

The level of IL-6 is a useful parameter for monitoring disease activity of SLE. In active SLE, no significant elevation of serum sIL-6R and no expression of APRF in PMBCs may be responsible for mild CRP elevation.

Identification and temporal expression pattern of genes modulated during irreversible growth arrest and terminal differentiation in human melanoma cells

Abnormalities in differentiation are common occurrences in human cancers. Treatment of human melanoma cells with the combination of recombinant human fibroblast interferon (IFN-beta) and the antileukemic compound mezerein (MEZ) results in a loss of tumorigenic potential that correlates with an irreversible suppression in proliferative ability and induction of terminal differentiation. It is hypothesized that this is associated with the differential expression of genes that may directly regulate cancer cell growth and differentiation. To define the relevant gene expression changes that correlate with and potentially control these important cellular processes a differentiation induction subtraction hybridization (DISH) scheme is being used. A temporally spaced subtracted differentiation inducer treated (TSS) cDNA library was constructed and differentially expressed DISH clones were isolated and evaluated using a high throughput microchip cDNA (Synteni) array screening approach. Verification of differential gene expression for specific cDNAs was confirmed by Northern blotting. The temporal kinetics of regulation and the expression pattern of DISH genes were also evaluated by microchip cDNA array screening. Using this approach with 1000 DISH cDNA clones (approximately 10% of the DISH library) has resulted in the identification and cloning of both 26 known and 11 novel cDNAs of potential relevance to growth control and terminal differentiation in human melanoma cells.

Correlation of clinical features and telomerase activity in human gliomas

Telomerase is a ribonucleoprotein containing an RNA template that synthesizes telomeric DNA. The expression of telomerase activity is concomitant with the attainment of immortality in tumor tissues and cells. In this report, we analyzed telomerase activity in 39 human gliomas with different histological, and in 10 meningiomas, 3 neurinomas, and 2 normal brain tissues by using a polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (TRAP) assay. Telomerase activity was detectable in almost all of the gliomas (36 of 39), but not in any of the meningiomas, neurinomas, or normal brain tissues. In addition, we also analyzed the level of telomerase activity in the 36 gliomas with positive telomerase activity. The relative telomerase activity of the glioma showed a clear association with the pathological grade of glioma; i.e., most of the tumors with high telomerase activity were pathologically of high grade. And also the relative level of telomerase activity could be correlated with the survival time of the patients. These results suggest that the level of telomerase activity in brain tumors is a diagnostic marker indicating the prognosis of the patient as well as the malignant potential of the tumor.

Boranophosphate nucleic acids--a versatile DNA backbone

Important chemical and biochemical properties of boranophosphate DNA and RNA oligonucleotides are reviewed. Stereoregular boranophosphate oligomers can be synthesized enzymatically and form stable duplexes with DNA. Fully boronated, non-stereoregular oligothymidylates, synthesized chemically, form hybrids with poly(A) that have lower melting points than oligothymidylate:poly(A), yet they nevertheless can support the RNase H mediated cleavage of RNA.

[Relationship between unhealthy dietary behavior and blood lipids and lipid peroxides in coronary heart disease patients]

The effects of unhealthy dietary behavior on blood lipids(TC, TG, HDL-C, LDL-C) and lipid peroxides (LPO) and the occurrence of coronary heart disease(CHD) were measured in 97 CHD patients and 97 controls without any clinical appearance of cardiovascular or cerebrovascular diseases. The results showed that the serum level of TC, TG, HDL-C, LDL-C and LPO were significantly higher in CHD group than control group. More unhealthy dietary behavior was observed in CHD group than in control group. The odds ratio of the population with more than 3 items of unhealthy dietary behavior was 3.88. The results of this study suggested that unhealthy dietary behavior might play an important role in increasing the risk of CHD.

Inheritance of resistance to bacillus thuringiensis toxin (Dipel ES) in the european corn borer

Resistance in the European corn borer, Ostrinia nubilalis (Hubner), to a commercial formulation of Bacillus thuringiensis (Bt) Berliner toxin, Dipel ES, appears to be inherited as an incompletely dominant autosomal gene. This contrasts with the inheritance of resistance to Bt in other insects, where it has usually been characterized as a recessive trait. The proposed high-dose/refuge strategy for resistance management in Bt maize depends on resistance being recessive or partially recessive. If field resistance turns out to be similar to this laboratory resistance, the usefulness of the high-dose/refuge strategy for resistance management in Bt maize may be diminished.

[Study on HCV genotypes in different clinical types of hepatitis C patients in Shenyang area]

OBJECTIVE

To study the distribution of HCV genotypes in different clinical types of hepatitis C in Shenyang area and its clinical significance.

METHODS

The HCV genotypes of 84 HC patients of different clinical types were detected by PCR assay with four kinds of type-specific primers.

RESULTS

In 84 patients with hepatitis C, the HCV-II and HCV-III genotypes and the II/III mixed genotype were 53.6%, 30.9% and 15.5% respectively. The distribution of HCV genotypes in different HC clinical types was not identical, P < 0.05. In acute hepatitis, in mild, moderate and severe degree of chronic hepatitis, and in liver cirrhosis, the infection rates of genotype II HCV were 55.6%, 36.2%, 75.0%, 85.7% and 88.9% respectively, but that of genotype III were 22.2%, 46.8%, 8.3%, 0% and 11.1% respectively.

CONCLUSION

Infection of geno type II HCV was predominant in Shenyang area followed by HCV-III and II/III mixed genotypes. The different genotypes of HCV were related to the severity of hepatitis C.

[A clinical and experimental study on autologous nail transplantation ophthalmoplasty]

OBJECTIVE

To seek for better materials for ophthalmoplasty.

METHODS

The nails were used as autografts in an experimental and a clinical study. The paws were subcutaneously grafted in the backs of 15 rabbits. The nails were used as the tarsus to constitute the lower eyelid on one patient. On another patient, the toenails were used to restore fracture of the base of the orbit.

RESULTS

Without reject reaction, the paws were encapsulated by fibrous tissue ten weeks after grafting. The six patients were followed up for 1 to 5 years and were satisfied with the plastic operations.

CONCLUSION

The nail is a practical and an effective autograft in ophthalmoplasty.

[Statistical analysis of complications of the frontalis aponeurosis flap for correction of complete blepharoptosis]

OBJECTIVE

The cause of and prophylactic measures for the complications of the frontalis aponeurosis flap suspension for correction of blepharoptosis were investigated to improve the operative results.

METHODS

Five hundred and thirteen patients who were found to have complications after frontalis aponeurosis flap suspension for blepharoptosis were studied by follow-up examinations.

RESULTS

Fourteen kinds of postoperative complications were found and cured.

CONCLUSION

Most of the postoperative complications following blepharoptosis correction can be prevented and well treated. The frontalis aponeurosis flap technique is reliable for correction of complete blepharoptosis.

[Color Doppler flow imaging study on the changes of collateral circulation between portal-superior vena cava and azygos vein before and after endoscopic ligation of the esophageal varix]

Color Doppler flow imaging (CDFI) was performed in 35 patients with portal hypertension and esophageal varix. Thirty subjects were served as control. After esophageal variceal ligation, CDFI observed that the portal-superior vena cava collateral veins were partialy blocked. The esophageal varices disappeared. The esophageal wall thinned. Diameter of left gastric vein enlarged and blood flow velocity decreased. Azygos diameter was reduced and blood flow velocity was decreased. Although diameter of portal vein was not changed, the blood flow velocity slightly increased. The results suggest that ligation treatment can have the tendency to increase blood flow of liver and stomach, which might aggravate gastric mucosal lesion.

Nuclear proteins from liver and kidney bind a 37 bp sequence in the 5' upstream region of the mGAT1 gene

The mouse GABA transporter (mGAT1) gene has been shown to be exclusively expressed in brain by Northern and Western blot analyses. The interactions between the 5' flanking region of the mGAT1 gene and nuclear proteins from different mouse tissues were studied by means of gel-shift assay. Our results show that nuclear protein factors from non-nervous tissues can specifically recognize a 37 bp sequence that is conserved in the 5' flanking region between the human and mouse GAT1 genes. Similar nuclear protein factors were also found to exist in rat, rabbit and pig.

Val 70, Phe 72 and the last seven amino acid residues of C-terminal are essential to the function of norepinephrine transporter

The norepinephrine transporter(NET) is a member of the Na+/Cl- dependent neurotransmitter transporter family and constitutes the target of several clinically important antidepressants. To delineate the critical amino acid residues and the function of C-terminal in regulating transport activity of NET, here we constructed two site mutants (V70F, F72V; V70I, F72V) and one C-terminal truncated mutant (delta 611-617). The wild type and mutants of NET were expressed in Xenopus oocytes by injection of their cRNA. We found that all of these mutants lost their transport activity. These results indicate that the amino acid residues of V70 and F72, and the last seven amino acids of C-terminal are essential to the transport activity of NET.

Kinetics at a multifunctional RNA active site

Kinetics of a self-capping RNA, Iso6, have been investigated to constrain the catalytic mechanism. The role of phosphates has been examined by varying the number of phosphates on the nucleophilic attacking group or on the RNA. While the number of phosphates in the nucleophile affects capping kinetics, only KM but not kcat is altered. The KM values for GMP, GDP, GTP and ppppG are 200, 11, 13 and 31 microM, respectively. A reaction product, pyrophosphate, is also found to strongly inhibit RNA activities through a competitive exchange mechanism with an apparent Ki of 200 nM. Uniquely strong binding of pyrophosphate supports the idea that capping originated by utilization of the initial pyrophosphate leaving group site for capping nucleophiles. In contrast to the nucleophile phosphate, change of 5' RNA terminus from triphosphate to tetraphosphate enhances the overall rate and kcat by 40%, with little effect on KM. Thus, only the leaving group appears to affect the rate of the chemical transformation. We propose two possible mechanisms that explain this apparent rate-limiting chemical step, either dissociation of pyrophosphate to form a metaphosphate monoester intermediate or formation of a circular phosphoramidate intermediate, using an internal RNA nitrogenous group. A single essential Ca ion is required for all activities.

Orally active indole N-oxide PDE4 inhibitors

This communication describes the synthesis and in vitro and in vivo evaluation of a novel potent series of phosphodiesterase type (IV) (PDE4) inhibitors. Several of the compounds presented possess low nanomolar IC50's for PDE4 inhibition and excellent in vivo activity for inhibition of TNF-alpha levels in LPS challenged mice (mouse endotoxemia model). Emesis studies (dog) and efficacy in a SCW arthritis model for the most potent PDE4 inhibitors are presented.