The K2 2(3)Pi(g) state: new observations and analysis

Totally 3045 transitions into the 2(3)Pi(g) v = 0-42, J = 0-103, Omega = 0, 1, 2 rovibrational levels have been observed by infrared-infrared double resonance fluorescence excitation and two-photon spectroscopy. Molecular constants including the spin-orbit interaction parameters are obtained. Although the K2 2(3)Pi(g) state dissociates to the 4s + 3d atomic limit, it is strongly mixed with the 3P ionic states in the range of the potential well. This mixing results in a relatively large equilibrium internuclear distance Re = 5.254 A and a larger spin-orbit constant A0 approximately 14.17 cm(-1) than that of the atomic limit -2.33 cm(-1). Strong perturbations of the 2(3)Pi(g) levels observed are attributed to the spin-orbit coupling with the 4(1)Sigma(g)+ state.

Neutron scattering study of novel magnetic order in Na0.5CoO2

We report polarized and unpolarized neutron scattering measurements of the magnetic order in single crystals of Na0.5CoO2. Our data indicate that below TN=88 K the spins form a novel antiferromagnetic pattern within the CoO2 planes, consisting of alternating rows of ordered and nonordered Co ions. The domains of magnetic order appear to be closely coupled to the domains of Na ion order, consistent with such a twofold symmetric spin arrangement. Magnetoresistance and anisotropic susceptibility measurements further support this model for the electronic ground state.

Sodium Cation Affinities of MALDI Matrices Determined by Guided Ion Beam Tandem Mass Spectrometry: Application to Benzoic Acid Derivatives†

Threshold collision-induced dissociation of Na(+)(xBA) complexes with Xe is studied using guided ion beam mass spectrometry. The xBA ligands studied include benzoic acid and all of the mono- and dihydroxy-substituted benzoic acids: 2-, 3-, and 4-hydroxybenzoic acid and 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, and 3,5-dihydroxybenzoic acid. In all cases, the primary product corresponds to endothermic loss of the intact xBA ligand. The cross section thresholds are interpreted to yield 0 and 298 K bond dissociation energies (BDEs) for Na(+)-xBA after accounting for the effects of multiple ion-neutral collisions, internal and kinetic energy distributions of the reactants, and dissociation lifetimes. Density functional theory calculations at the B3LYP/6-31G* level of theory are used to determine the structures of these complexes and provide the molecular constants necessary for the thermodynamic analysis of the experimental data. Theoretical BDEs are determined at the B3LYP/6-311+G(2d,2p) and MP2(full)/6-311+G(2d,2p) levels using the B3LYP/6-31G* optimized geometries. The trends in the measured BDEs suggest two very different binding modes for the Na(+)(xBA) complexes, while theory finds four. In general, the most stable binding conformation involves the formation of a six-membered chelation ring via interaction with the carbonyl and 2-hydroxyl oxygen atoms. The ground state geometries of the Na(+)(xBA) complexes in which the ligand does not possess a 2-hydroxyl group generally involve binding of Na(+) to either the carbonyl oxygen atom or to both oxygen atoms of the carboxylic acid group. These binding modes tend to be competitive because the enhancement in binding associated with the chelation interactions in the latter is mediated by steric repulsion between the hydroxyl and ortho hydrogen atoms. When possible, hydrogen bonding interactions with the ring hydroxyl group(s) enhance the stability of these complexes. The agreement between the theoretical and experimental BDEs is quite good for B3LYP and somewhat less satisfactory for MP2(full).

Th2-dominated antitumor immunity induced by DNA immunization with the genes coding for a basal core peptide PDTRP and GM-CSF

Our previous study showed that DNA vaccination with a plasmid vector encoding a core peptide of mucin1 (PDTRP) provided modest protection against challenge with tumor cells that expressed mucin1 protein. We report here that a DNA vaccine comprising a modified PDTRP plasmid and GM-CSF coding sequence at the C-terminus induced better protection against tumor challenge. The increased protection was directly correlated with a stronger PDTRP-specific immune response induced by the GM-CSF fusion plasmid. The plasmid encoding GM-CSF and the target PDTRP antigen induced a greater PDTRP-specific Th proliferation, antibodies, and cytotoxicity. Interestingly, the modified plasmid vaccine predominantly enhanced the type 2 immune responses manifested by an increased IgG1 to IgG2a antibody ratio and a greater induction of GATA-3 and IL-4 mRNA than that of T-bet and IFN-gamma mRNA in spleen cells from vaccinated mice. In addition, protection against tumor challenge in vaccinated mice showed that there was no significant change in mice survival after in vivo CD8+CTL depletion, indicating that antitumor immunity augmented by plasmid encoding GM-CSF and target PDTRP gene vaccine was dominated by Th2 immune response.

Bone mineral density in children with thalassaemia major: determining factors and effects of bone marrow transplantation

Osteoporosis and osteopenia affect up to half of patients with thalassaemia major (TM). We investigate the effects of acquired factors and BMT on bone mineral density (BMD) in these patients. In all, 53 patients on regular transfusion (BT group) and 33 patients at 5.7+/-1.9 years post transplant (BMT group) were recruited. BMD was measured by dual energy X-ray absorptiometry. Serum concentrations of osteocalcin, bone-specific alkaline phosphatase (ALP), beta-crossLap and urinary cross-linking deoxypyridinoline (DPD) were measured by chemiluminescence and enzyme immunoassay, respectively. Severe BMD deficit (Z-score <-2.5) at spine and hip were noted in 62 and 35% of BT group. Serum osteocalcin (beta=-0.463; P=0.006) was predictive of spine BMD, whereas age (beta=-0.843; P=0.007) and urine DPD (beta=-0.439; P=0.037) were associated with hip BMD in BT group. Among BMT patients, post transplant duration (beta=0.450; P=0.009) and serum bone-specific ALP (beta=-0.495; P=0.013) were associated with spine BMD. Severe BMD deficit was less common among BMT than BT patients (6 vs 35%; P=0.036). The mean (s.d.) osteocalcin levels in BMT and BT groups were 96.4 (72.7) microg and 68.9 (40.3) microg/l, respectively (P=0.037). In conclusion, severe BMD deficit is common in Chinese TM patients and BMT may reverse BMD deficit in these patients.

Allogenic donor splenocytes pretreated with antisense peptide against B7 prolong cardiac allograft survival

The interaction of T cell CD28/CTLA-4 receptors with B7 on antigen-presenting cells (APCs) represents an important co-stimulatory pathway in T cell activation or anergy. Our previous study indicated that recipients immunized with allogenic donor immature dendritic cells (DCs) or resting B cells could induce specific immune tolerance and prolong allograft survival. A possible mechanism for this observation is that the expression of B7 molecules is either at a low level or lacking on these cells. The present study investigates whether blockade of B7 molecules on donor splenocytes with a B7 antisense peptide (B7AP), i.e. a peptide analogue of the CD28-binding region, could induce specific immune tolerance and prolong allograft survival in the recipients. Both the lymphocyte proliferation reaction and the mice pinna cardiac allograft experiment were performed to evaluate the role of B7AP in inducing specific immune tolerance in recipients in vitro and in vivo. The results showed that 56.65% and 20.52% of C57BL/6 splenocytes expressed B7.1 and B7.2 molecules, respectively, on their cell surface. There were no significant changes of the B7 expression on such splenocytes after being treated by the B7AP (53.28% and 19.06%, respectively). B7AP inhibited the mixed lymphocyte reaction by up to 38.4% and a dose-response correlation was observed for inhibition. The recipients (BALB/c) immunized with B7AP-pretreated C57BL/6 splenocytes induced a specific immune hypo-response (43%versus control) and notably prolonged survival of the C57BL/6 cardiac allograft by up to 20.3 days. In contrast to the normal saline group (average: 8.6 days) and FTD(10) control peptide group (<4 days), the cardiac allograft survival of the test group was extended for an additional 11.7 days. These results strongly support the notion that immunization with donor splenocytes, which had been pretreated with B7AP, induced specific immune tolerance and prolonged allograft survival in the recipients.

Comparison of water and lipid content measurements using diffuse optical spectroscopy and MRI in emulsion phantoms

We present a quantitative comparison of lipid and water signals obtained from broadband Diffuse Optical Spectroscopy (DOS) and Magnetic Resonance Imaging (MRI). DOS and MRI measurements were performed on an identical set of emulsion phantoms that were composed of different water/soybean oil fractions. Absolute concentrations of water and lipid ranging from 35-94% and 63-6%, respectively were calculated from quantitative broadband near-infrared (NIR) absorption spectra (650-1000 nm). MR images of fat and water were separated using the three-point Dixon technique. DOS and MRI measured water and lipid were highly correlated (R(2) = 0.98 and R(2) = 0.99, respectively) suggesting that these techniques are complementary over a broad range of physiologically relevant water and lipid values. In addition, comparison of DOS derived concentrations to the MRI "gold standard" technique validates our quantitation approach and permits estimation of DOS accuracy and sensitivity in vivo.

Cyclosporine enhances vasorelaxation in coronary but not pulmonary artery after 16-hour preservation with UW solution

Cyclosporine (CsA), a calcineurin inhibitor, has been associated with endothelial dysfunction in transplant patients. Human and in vitro studies suggest that CsA produces endothelial dysfunction by impairing vascular endothelium-dependent relaxation. However, little is know about the CsA effects to modulate the vasorelaxation after prolonged graft preservation. In this study using a protocol designed to eliminate the influences of infusion pressure and shear stress, we evaluated the effect of CsA on vasorelaxation of coronary and pulmonary arteries after 16-hour University of Wisconsin (UW) solution preservation.

Cloning of human myeloid-associated differentiation marker (MYADM) gene whose expression was up-regulated in NB4 cells induced by all-trans retinoic acid

A full-length cDNA of 3192 bp isolated from human bone marrow cDNA library was predicted an ORF encoding 298 amino acids. The deduced protein, containing seven putative transmembrane segments and sharing 75.8% amino acid identity with mouse Myadm protein, was named as human MYADM. The results of Northern blot analysis showed that MYADM was ubiquitously expressed in 15 of 16 adult tissues tested, except thymus. To determine whether the novel human gene was involved in hematopoietic differentiation process as mouse Myadm did, we examined the mRNA expressive abundance of this gene between normal bone marrow cells and peripheral blood leukocytes, and detected the expression change in NB4 cells induced by all-trans retinoic acid at different induce time by the semi-quantitative RT-PCR. The results showed that the expression of the novel gene was not only significantly higher in peripheral blood leukocytes than in bone marrow cells, but also significantly up-regulated when the NB4 cells(derived from a patient with acute promyelocytic leukemia) were induced by all-trans retinoic acid (ATRA) for 48hr. It is suggested that human MYADM was also associated with the differentiation of hematopoietic cells or acute promyelocytic leukemia cells. In addition, MYADM was mapped to human chromosome 19q 13.33-q 13.4 by Radiation Hybrid mapping, and it consists of 3 exons and 2 introns and spans a 7.1-Kb genomic region.

Water maze performance and changes in serum corticosterone levels in zinc-deprived and pair-fed rats

The aims of the present study were (1) to evaluate the learning and short- and long-term memory of zinc-deprived (ZD) and pair-fed (PF) rats in a Morris water maze (MWM) and (2) to monitor the serum corticosterone levels of these rats before and after swimming. Young Sprague-Dawley rats (aged 27-31 days) consumed AIN-93G diet for 10 days, and then were separated into ad libitum control (CT), PF and ZD groups. The zinc content of the diet was 25-30 ppm (CT and PF) or <1 ppm (ZD). After 17 days on experimental diets, a MWM was used to test spatial cognition. Delayed-matching-to-place (DMP) test results indicate that both zinc deprivation and food restriction had no effect on short-term memory. The PF rats exhibited significantly impaired learning and thigmotaxia (i.e., wall hugging) in the learning test. The PF group also demonstrated less preference for the target zone in the first 15 s of the probing test. When the total 120 s of the probing test was considered, there were no differences in preference for the target zone, but thigmotaxia was greater in the PF than the CT group. The only behavioral change of the ZD group was thigmotaxia observed during the 120-s probing test following training, indicating the increment of anxiety. Morning basal corticosterone levels before swim training were significantly elevated in the PF group on Day 15 of dietary treatment, whereas a significant elevation of the basal corticosterone level in the ZD group was not statistically significant until Day 22. The data indicate an association between impaired learning, poor searching strategy and elevated corticosterone in the PF group. In contrast, the ZD rats showed normal cognitive performance but had elevated corticosterone and increased anxiety-like behavior (thigmotaxia).

Gene transfer of inducible nitric oxide synthase impairs relaxation in human and rabbit cerebral arteries

BACKGROUND AND PURPOSE

These studies evaluated whether gene transfer of inducible nitric oxide synthase (iNOS) is a sufficient stimulus to produce vascular dysfunction in cerebral arteries.

METHODS

Intracranial (pial) arteries were dissected from human brain tissue obtained during elective surgery. Isolated human arteries were incubated in vitro with adenovirus containing iNOS (AdiNOS) or a nonexpressive transgene (control, AdBglII) (500 micro L, 3x10(9) plaque-forming units per milliliter), and vascular function was examined 24 hours later. In anesthetized rabbits, AdiNOS or AdBglII (300 microL 1x10(10)) was injected into the cisterna magna. Three days later, the basilar artery was removed, and reactivity was examined ex vivo.

RESULTS

In submaximally precontracted vessels, we observed impairment of NO-dependent relaxation in human cerebral arteries after gene transfer of iNOS. Maximum relaxation to bradykinin (1 micromol/L, an endothelium-dependent agonist) was 77+/-11% (mean+/-SE) after AdBglII and 31+/-22% (P<0.05) after AdiNOS. After AdiNOS, responses to nitroprusside (an endothelium-independent NO donor) also were impaired. Responses to both nitroprusside and bradykinin were improved by aminoguanidine (300 micromol/L), an inhibitor of iNOS. AdiNOS produced no change in vasoconstrictor responses to U46619. In basilar arteries from rabbits examined in vitro after gene transfer in vivo, responses to histamine, serotonin, and nitroprusside all were similar after AdiNOS or AdBglII. In contrast, relaxation to acetylcholine was significantly depressed after AdiNOS. Maximum relaxation to acetylcholine (10 micromol/L) was 90+/-3% after AdBglII and 68+/-5% (P<0.05) after AdiNOS. Relaxation of arteries after AdiNOS was improved by aminoguanidine.

CONCLUSIONS

These studies suggest that expression of iNOS may impair NO-dependent relaxation in both human and rabbit cerebral arteries.

Solvation of copper ions by acetone. structures and sequential binding energies of Cu+(acetone)x, x = 1-4 from collision-induced dissociation and theoretical studies

Collision-induced dissociation of Cu+(acetone)(x), x = 1-4, with Xe is studied as a function of kinetic energy using guided ion beam mass spectrometry. In all cases, the primary and lowest energy dissociation channel observed is endothermic loss of one acetone molecule. The primary cross section thresholds are interpreted to yield 0 and 298 K bond energies after accounting for the effects of multiple ion-neutral collisions, internal energy of the complexes, and dissociation lifetimes. Density functional calculations at the B3LYP/6-31G* level of theory are used to determine the structures of these complexes and provide molecular constants necessary for the thermodynamic analysis of the experimental data. Theoretical bond dissociation energies are determined from single point calculations at the B3LYP/6-311+G(2d,2p) and MP2(full)/6-311+G(2d,2p) levels, using the B3LYP/6-31G* optimized geometries. The experimental bond energies determined here are in good agreement with previous experimental measurements made in a high-pressure mass spectrometer for the sum of the first and second bond energy (i.e., Cu+(acetone)2 --> Cu+ + 2 acetone) when these results are properly anchored. The agreement between theory and experiment is reasonable in all cases, but varies both with the size of the cluster and the level of theory employed. B3LYP does an excellent job for the x = 1 and 3 clusters, but is systematically low for the x = 2 and 4 clusters such that the overall trends in sequential binding energies are not parallel. In contrast, all MP2 values are somewhat low, but the overall trends parallel the measured values for all clusters. The trends in the measured Cu+(acetone), binding energies are explained in terms of 4s-3d sigma hybridization effects and ligand-ligand repulsion in the clusters.

Juvenile hormone III-dependent conformational changes of the nuclear receptor ultraspiracle

The identification of potential endogenous or synthetic ligands for orphan receptors in the steroid receptor superfamily is important both for discerning endogenous regulatory pathways and for designing receptor inhibitors. The insect nuclear receptor Ultraspiracle (USP), an ortholog of vertebrate RXR, has long been treated as an orphan receptor. We have tested here the fit of terpenoid ligands to the JH III-binding site of monomeric and homo-oligomeric USP from Drosophila melanogaster (dUSP). dUSP specifically bound juvenile hormone III (JH III), but not control farnesol or JH III acid, and also specifically changed in conformation upon binding of JH III in a fluorescence binding assay. Juvenile hormone III binding caused intramolecular changes in receptor conformation, and stabilized the receptor's dimeric/oligomeric quaternary structure. In both a radiometric competition assay and the fluorescence binding assay the synthetic JH III agonist methoprene specifically competed with JH III for binding to dUSP, the first demonstration of specific binding of a biologically active JH III analog to an insect nuclear receptor. The recombinant dUSP bound with specificity to a DR12 hormone response element in a gel shift assay. The same DR12 element conferred enhanced transcriptional responsiveness of a transfected juvenile hormone esterase core promoter to treatment of transfected cells with JH III, but not to treatment with retinoic acid or T3. The activity of JH III or JH III-like structures, but not structures without JH III biological activity, to bind specifically to dUSP and activate its conformational change, provide evidence of a terpenoid endogenous ligand for Ultraspiracle, and offer the prospect that synthetic, terpenoid structures may be discovered that can agonize or antagonize USP function in vivo.

Differentiation and migration of astrocyte precursor cells and astrocytes in human fetal retina: relevance to optic nerve coloboma

The presence of astrocyte precursor cells (APCs) and time course and topography of astrocyte differentiation during development were investigated by triple-label immunohistochemistry with intact fetal and adult human retinas. Throughout retinal development and adulthood, expression of Pax2 was restricted to cells of the astrocytic lineage. Three distinct stages of astrocytic differentiation were identified during development: i) Pax2+/vimentin+/GFAP- APCs; ii) Pax2+/vimentin+/GFAP+ immature perinatal astrocytes; and iii) Pax2+/vimentin-/GFAP+ mature perinatal astrocytes. In adult, cells with the antigenic phenotype of mature perinatal astrocytes were restricted to a region surrounding the optic nerve head (ONH), whereas cells at a fourth stage of differentiation, adult astrocytes (Pax2-/vimentin-/GFAP+), were apparent throughout the vascularized retina. APC appearance was centered around the ONH and preceded the appearance of perinatal astrocytes. A cluster of Pax2+ somas was also present in a small region surrounding the ONH at the ventricular surface of the developing retina, which suggests the existence of two distinct sites of astrocytic differentiation. The coincidence in the location of APCs and perinatal astrocytes at the ventricular zone with that of optic nerve colobomas, together with the association of Pax2 gene mutations with this condition, suggests that coloboma formation may result from impaired astrocyte differentiation during development.

An experimental study on drugs for improving blood circulation and removing blood stasis in treating mild chronic hepatic damage

Large and small doses of drugs for improving blood circulation and removing blood stasis were used in model rats to treat mild chronic hepatic damage induced by carbon tetrachloride (CCl4). The results show that large dose of Dang Gui ([symbol: see text] Radix Angelicae Sinensis) and Dan Shen ([symbol: see text] Radix Salviae Miltiorrhizae) (drugs for regulating blood flow) and small dose of Yu Jin ([symbol: see text] Radix Curcumae) and Niu Xi ([symbol: see text] Radix Achyranthis Bidentatae) (drugs for activating blood flow) can significantly elevate the activity of SOD (P < 0.05) and/or lower the T/K ratio, markedly reduce the MDA content (P < 0.05 or P < 0.01) and significantly decrease the activities of ALT and AST (P < 0.05 or P < 0.01), demonstrating that these drugs are effective in combating oxygen free radicals (OFR) in chronic liver damage. On the contrary, large dose of Tu Bie Chong ([symbol: see text] Eupolyphaga seu Steleophaga) and E Zhu ([symbol: see text] Rhizoma Curcumae) (drugs for removing blood stasis) tend to increase the ALT and AST (P < 0.05) activities. The results suggest that the synergism of elevation of the SOD activity and reduction of T/K ratio contributes to the action of drugs for improving blood circulation and removing blood stasis in combating the liver damage induced by CCl4.

Down-regulation of trkA mRNA within nucleus basalis neurons in individuals with mild cognitive impairment and Alzheimer's disease

Recent studies indicate that trkA expression is reduced in end-stage Alzheimer's disease (AD). However, understanding the neuropathologic correlates of early cognitive decline, as well as the changes that underlie the transition from nondemented mild cognitive impairment (MCI) to AD, are more critical neurobiological challenges. In these regards, the present study examined the expression of trkA mRNA in individuals diagnosed with MCI and AD from a cohort of people enrolled in a Religious Orders Study. Individuals with MCI and AD displayed significant reductions in trkA mRNA relative to aged-matched controls, indicating that alterations in trkA gene expression occur early in the disease process. The magnitude of change was similar in MCI and AD cases, suggesting that further loss of trkA mRNA is not necessarily associated with the transition of individuals from nondemented MCI to AD. The loss of trkA mRNA was not associated with education, apolipoprotein E allele status, gender, Braak score, global cognitive score or Mini-Mental Status Examination. In contrast, the loss of trkA mRNA in MCI and AD was significantly correlated with function on a variety of episodic memory tests.

NO-dependent vasorelaxation is impaired after gene transfer of inducible NO-synthase

Proinflammatory stimuli produce expression of inducible NO-synthase (iNOS) within blood vessels and are associated with impaired endothelium-dependent relaxation. Gene transfer of iNOS was used to test the hypothesis that expression of iNOS in blood vessels produces impairment of NO-dependent relaxation as well as contraction. An adenoviral vector containing cDNA for murine iNOS, AdCMViNOS, and a control virus, AdCMVBglII, were used for gene transfer to rabbit carotid arteries in vitro and in vivo. After gene transfer of iNOS in vitro, contractile responses to KCl, phenylephrine, and U46619 were impaired. Relaxation in response to acetylcholine, ADP, A23187, and nitroprusside was also impaired. For example, maximum relaxation of vessels to acetylcholine (10 micromol/L) was 78+/-4% (mean+/-SE) after AdBglII (10(10.5) plaque-forming units) and 34+/-5% after AdiNOS (10(10.5) plaque-forming units, P<0.05). NO-independent relaxation in response to 8-bromo-cGMP and papaverine was not impaired after AdiNOS. Contraction and relaxation were improved in carotid arteries expressing iNOS by aminoguanidine and L-N-iminoethyl lysine, inhibitors of iNOS. After intraluminal gene transfer of iNOS in vivo, contraction of vessels in vitro was normal, but responses to acetylcholine were impaired. In summary, the major finding is that NO-dependent relaxation is impaired in arteries after gene transfer of iNOS in vitro and in vivo. Thus, expression of iNOS per se impairs NO-dependent relaxation.

[Study on the transformation from myelodysplastic syndromes into acute leukemias]

OBJECTIVE

To study the patterns of transformation from myelodysplastic syndromes (MDS) into acute leukemias (AL).

METHODS

Leukemic transformation of MDS patients was dynamically followed up and the clinical manifestations, peripheral blood and bone marrow pictures, karyotypes, immunophenotypes, response to treatment and prognosis of post MDS acute leukemia (postMDS-AL) were observed.

RESULTS

During the past eight year and seven months, 21 (13.91%) of 151 MDS patients progressed to overt leukemia with a median interval of 5 (1 - 21) months. There were no significant differences among the rates of leukemia from RA, RAEB and RAEB-t groups. The transformation was developed either gradually or rapidly. There were five parameters related to the leukemic transformation: under 40 years of age, pancytopenia, more than 0.15 blasts in bone marrow, at least two types of abnormal karyotype and combined chemotherapy. All of the 21 post MDS-AL were acute myeloid leukemia (AML); and most of them were M(2), M(4) and M(5). Two (9.52%) post MDS-AML developed extramedullary infiltration. Leukopenia was found in 47.62% of patients. Two third of the patients, whose bone marrows were generally hypercellular, showed neutropenias. After evolving into AML, 8 (47.06%) patients developed abnormal karyotypes. High expression of immature myeloid antigens, including CD(33) (49.83 +/- 24.50)%, CD(13) (36.38 +/- 33.84)%, monocytic antigen CD(14) (38.50 +/- 24.60)%, and stem cell marker CD(34) (34.67 +/- 30.59)% were found on bone marrow mononuclear cells of post MDS-AML cases. In some cases, lymphoid antigens, such as CD(5), CD(7), CD(9) and CD(19) were coexisted with myeloid antigens. A low complete remission rate (31.25%) and short survival duration with median survival of 6 (1 - 28) months were found in patients with post MDS-AML treated by induction therapy.

CONCLUSION

MDS was at high risk of evolving into AML, either gradually or rapidly. Patients with post MDS-AML had specific biologic features and worse prognoses.

[Sequential intensified immunosuppressive therapy combining with hematopoietic growth factors in the treatment of severe aplastic anemia]

OBJECTIVE

To explore more effective regimen for reducing early mortality of severe aplastic anemia (SAA) and improving therapeutic effectiveness.

METHODS

Antilymphocyte globulin/antithymocyte globulin (ALG/ATG) and cyclosporine A (CsA) (sequential intensified immunosuppressive therapy, SIIST), with or without hematopoietic growth factors (HGFs) were administered to 73 SAA patients in a prospective randomized clinical trial to test the effectiveness of the addition of HGFs for the patients.

RESULTS

The response rate of SIIST with HGFs group was significantly higher than that of SIIST alone group (89.2% vs 63.9%), with lower rates of early infection (24.3% vs 55.3%) and mortality (4.0% vs 16.7%), shorter duration of cytopenia and blood transfusion dependence and faster recovery of bone marrow hematopoiesis. The addition of HGFs to SIIST was tolerated well in all patients. There was no difference in the treatment outcome of the two groups with GM-CSF plus Epo or G-CSF plus Epo.

CONCLUSION

The use of HGFs in combination with SIIST could reduce early infection and mortality rates and, therefore, improve the response rates in SAA patients.

Systemic administration of the immunophilin ligand GPI 1046 in MPTP-treated monkeys

Systemic administration of immunophilin ligands provides trophic influences to dopaminergic neurons in rodent models of Parkinson's disease (PD) resulting in the initiation of clinical trials in patients with Parkinson's disease. We believe that prior to clinical trials, novel therapeutic strategies should show safety and efficacy in nonhuman models of PD. The present study assessed whether oral administration of the immunophilin 3-(3-pyridyl)-1-propyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-pyrrollidinecarboxylate (GPI 1046) could prevent the structural and functional consequences of n-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration in nonhuman primates. Twenty-five rhesus monkeys received daily oral administration of vehicle (n = 5) or one of four doses of GPI 1046 (0.3 mg/kg, n = 5; 1.0 mg/kg, n = 5; 3.0 mg/kg, n = 5; 10.0 mg/kg, n = 5). Two weeks after starting the drug treatment, all monkeys received a unilateral intracarotid injection of MPTP-HCl (3 mg). Daily drug administration continue for 6 weeks postlesion after which time the monkeys were sacrificed. Monkeys were assessed for performance on a hand reach task, general activity, and clinical dysfunction based on a clinical rating scale. All groups of monkeys displayed similar deficits on each behavioral measure as well as similar losses of tyrosine hydroxylase (TH)-immunoreactive (ir) nigral neurons, TH-mRNA, and TH-ir striatal optical density indicating that in general treatment failed to have neuroprotective effects.

[Immunorelated pancytopenia]

OBJECTIVE

A report of a group of patients with pancytopenia which might be related to abnormal immunity.

METHODS

The clinical and laboratory features of 29 patients with positive bone marrow mononuclear cell (BMMNC) Coombs tests were analyzed.

RESULTS

Most of these cases were pancytopenia with normal or decreased bone marrow cellularities and increased normoblasts. They were all found to have negative results of conventional hemolysis tests and hematopoietic nutrient determination and had no evidence of malignant clonal hematopoiesis. However, all of them showed positive BMMNC-Coombs test and good response to corticosteroids.

CONCLUSION

Immunorelated pancytopenia might be caused by abnormal immunity (especially autoantibody) mediated destruction or abnormal function of blood cells. It is beneficial to differentiate immunorelated pancytopenia from aplastic anemia or myelodysplastic syndromes.

Vascular cell adhesion molecule-1 augments adenovirus-mediated gene transfer

We have reported that adenovirus-mediated gene transfer is augmented in the endothelium of atherosclerotic blood vessels. We observed that vascular cell adhesion molecule-1 (VCAM-1) shares some homology with the coxsackievirus and adenovirus receptor. Because VCAM-1 is upregulated on atherosclerotic endothelial cells, we hypothesized that VCAM-1 may act as an auxiliary receptor to augment adenovirus-mediated gene transfer. To test this hypothesis, stable NIH 3T3 cell lines that constitutively express VCAM-1 on the cell surface were generated. Recombinant adenovirus 5 (Ad5), which contains the reporter ss-galactosidase gene, was used to compare Ad5 infection in VCAM-1(+) and parental NIH 3T3 cells. Total ss-galactosidase activity and the number of transgene-positive cells were 6- to 10-fold and 5-fold higher, respectively, in VCAM-1(+) than in VCAM-1(-) cells. Ad5 binding to VCAM-1(+) cells was increased by 3-fold over VCAM-1(-) cells. Soluble VCAM-1 protein, present during infection or viral binding, reduced ss-galactosidase activity in VCAM-1(+) cells in a dose-dependent manner. Taken together, we conclude that VCAM-1 can mediate adenovirus binding and infection. This may explain, in part, the previous finding that adenovirus-mediated gene transfer is augmented in atherosclerotic arteries.

Loss and atrophy of layer II entorhinal cortex neurons in elderly people with mild cognitive impairment

Layer II of the entorhinal cortex contains the cells of origin for the perforant path, plays a critical role in memory processing, and consistently degenerates in end-stage Alzheimer's disease. The extent to which neuron loss in layer II of entorhinal cortex is related to mild cognitive impairment without dementia has not been extensively investigated. We analyzed 29 participants who came to autopsy from our ongoing longitudinal study of aging and dementia composed of religious clergy (Religious Orders Study). All individuals underwent detailed clinical evaluation within 12 months of death and were categorized as having no cognitive impairment (n = 8), mild cognitive impairment (n = 10), or mild or moderate Alzheimer's disease (n = 11). Sections through the entorhinal cortex were immunoreacted with an antibody directed against a neuron-specific nuclear protein (NeuN). Stereological counts of NeuN-immunoreactive stellate cells, their volume, and the volume of layer II entorhinal cortex were estimated. Cases exhibiting no cognitive impairment averaged 639,625 +/- 184,600 layer II stellate neurons in the right entorhinal cortex. Individuals with mild cognitive impairment (63.5%; p < 0.0003) and mild or moderate Alzheimer's disease (46.06%; p < 0.0017) displayed significant losses of layer II entorhinal cortex neurons relative to those with no cognitive impairment but not relative to each other (p > 0.33). There was also significant atrophy of layer II entorhinal cortex neurons in individuals with mild cognitive impairment (24.1%) and Alzheimer's disease (25.1%). The volume of layer II was also reduced in individuals with mild cognitive impairment (26.5%), with a further reduction in those with Alzheimer's disease (46.4%). The loss and atrophy of layer II entorhinal cortex neurons significantly correlated with performance on clinical tests of declarative memory. Atrophy of layer II entorhinal cortex and the neurons within this layer significantly correlated with performance on the Mini Mental Status Examination. These data indicate that atrophy and loss of layer II entorhinal cortex neurons occur in elderly subjects with mild cognitive impairment prior to the onset of dementia and suggests that these changes are not exacerbated in early Alzheimer's disease.

Gene transfer of extracellular superoxide dismutase increases superoxide dismutase activity in cerebrospinal fluid

BACKGROUND AND PURPOSE

Copper-zinc superoxide dismutase (CuZnSOD) is expressed intracellularly, while extracellular SOD (EC-SOD) is released from cells. The purpose of this study was to determine whether gene transfer of CuZnSOD increases SOD activity predominantly in tissues, and gene transfer of EC-SOD increases SOD activity in cerebrospinal fluid (CSF). We also determined whether heparin or dextran sulfate releases EC-SOD into CSF.

METHODS

We injected recombinant adenoviruses expressing EC-SOD (AdEC-SOD), CuZnSOD (AdCuZnSOD), or beta-galactosidase (Adbeta-gal) into the cisterna magna of rabbits.

RESULTS

Total SOD activity in CSF was 39+/-11 U/mL (mean+/-SE) before virus injection. Three days later, total SOD activity in CSF increased to 148+/-22 U/mL after AdEC-SOD and 92+/-10 U/mL after AdCuZnSOD (P:<0.05 versus AdEC-SOD), with no change after Adbeta-gal (49+/-5 U/mL). EC-SOD protein was detected in CSF after AdEC-SOD but not AdCuZnSOD or Adbeta-gal. Injection of heparin or dextran sulfate into the cisterna magna increased total SOD activity 27-fold and 32-fold over basal values, respectively, in CSF of rabbits that received AdEC-SOD. In contrast to effects in CSF, total SOD activity in basilar artery and meninges was significantly higher after AdCuZnSOD and tended to be higher after AdEC-SOD than after Adbeta-gal.

CONCLUSIONS

-We have developed a method for intracranial gene transfer of CuZnSOD and EC-SOD. After gene transfer, CuZnSOD was expressed mainly in tissues, and EC-SOD was released into the CSF, especially after injection of heparin or dextran sulfate. Gene transfer of different isoforms of SOD may be useful in studies of cerebral vascular physiology and pathophysiology.

[Nitrogen dynamics in different organs of Calamagrostis angustifolia and Carex lasiocarpa in Sanjiang plain]

The dynamics of nitrogen content and storage in different organs of Calamagrostis angustifolia and Carex lasiocarpa which are dominant vegetation in swamp wetland were determined, and the utilization rate of nitrogen and its nutrient limitation in the region were analyzed. The results showed that the aboveground and underground biomass might be described by p = gamma + alpha t + beta t2 and p = a0 + b0t, respectively. The content of total N, NH4(+)-N and NO3(-)-N varied widely with different organs because of the effects of soil water, nutrient content, atmospheric temperature, vegetable feature and selective absorption to nitrogen, etc. The content of NO3(-)-N in different organs varied less than that of NH4(+)-N, and NH4(+)-N/NO3(-)-N was < 1. The N:P content less than 14 in two vegetations showed that it was N but not P was the limitation nutrient to the growth of vegetation in this region, moreover, the limitation was less in July than in August. This conclusion was also drawn from the analysis of the NH4(+)-N and NO3(-)-N content in soil.

Role of inwardly rectifying K(+) channels in K(+)-induced cerebral vasodilatation in vivo

We tested whether activation of inwardly rectifying K(+) (Kir) channels, Na(+)-K(+)-ATPase, or nitric oxide synthase (NOS) play a role in K(+)-induced dilatation of the rat basilar artery in vivo. When cerebrospinal fluid [K(+)] was elevated from 3 to 5, 10, 15, 20, and 30 mM, a reproducible concentration-dependent vasodilator response was elicited (change in diameter = 9 +/- 1, 27 +/- 4, 35 +/- 4, 43 +/- 12, and 47 +/- 16%, respectively). Responses to K(+) were inhibited by approximately 50% by the Kir channel inhibitor BaCl(2) (30 and 100 microM). In contrast, neither ouabain (1-100 microM, a Na(+)-K(+)-ATPase inhibitor) nor N(G)-nitro-L-arginine (30 microM, a NOS inhibitor) had any effect on K(+)-induced vasodilatation. These concentrations of K(+) also hyperpolarized smooth muscle in isolated segments of basilar artery, and these hyperpolarizations were virtually abolished by 30 microM BaCl(2). RT-PCR experiments confirmed the presence of mRNA for Kir2.1 in the basilar artery. Thus K(+)-induced dilatation of the basilar artery in vivo appears to partly involve hyperpolarization mediated by Kir channel activity and possibly another mechanism that does not involve hyperpolarization, activation of Na(+)-K(+)-ATPase, or NOS.

Neurodegeneration prevented by lentiviral vector delivery of GDNF in primate models of Parkinson's disease

Lentiviral delivery of glial cell line-derived neurotrophic factor (lenti-GDNF) was tested for its trophic effects upon degenerating nigrostriatal neurons in nonhuman primate models of Parkinson's disease (PD). We injected lenti-GDNF into the striatum and substantia nigra of nonlesioned aged rhesus monkeys or young adult rhesus monkeys treated 1 week prior with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Extensive GDNF expression with anterograde and retrograde transport was seen in all animals. In aged monkeys, lenti-GDNF augmented dopaminergic function. In MPTP-treated monkeys, lenti-GDNF reversed functional deficits and completely prevented nigrostriatal degeneration. Additionally, lenti-GDNF injections to intact rhesus monkeys revealed long-term gene expression (8 months). In MPTP-treated monkeys, lenti-GDNF treatment reversed motor deficits in a hand-reach task. These data indicate that GDNF delivery using a lentiviral vector system can prevent nigrostriatal degeneration and induce regeneration in primate models of PD and might be a viable therapeutic strategy for PD patients.

Gene transfer of calcitonin gene-related peptide prevents vasoconstriction after subarachnoid hemorrhage

We sought to determine whether adenovirus-mediated gene transfer in vivo of calcitonin gene-related peptide (CGRP), a potent vasodilator, ameliorates cerebral vasoconstriction after experimental subarachnoid hemorrhage (SAH). Arterial blood was injected into the cisterna magna of rabbits to mimic SAH 5 days after injection of AdRSVCGRP (8x10(8) pfu), AdRSVbetagal (control virus), or vehicle. After injection of AdRSVCGRP, there was a 400-fold increase in CGRP in cerebrospinal fluid. Contraction of the basilar artery to serotonin in vitro was greater in rabbits after SAH than after injection of artificial cerebrospinal fluid (P<0.001). Contraction to serotonin was less in rabbits with SAH after AdRSVCGRP than after AdRSVbetagal or vehicle (P:<0.02). Basal diameter of the basilar artery before SAH (measured with digital subtraction angiogram) was 13% greater in rabbits treated with AdRSVCGRP than in rabbits treated with vehicle or AdRSVbetagal (P:<0.005). In rabbits treated with vehicle or AdRSVbetagal, arterial diameter after SAH was 25+/-3% smaller than before SAH (P<0.0005). In rabbits treated with AdRSVCGRP, arterial diameter was similar before and after SAH and was reduced by 19+/-3% (P<0.01) after intracisternal injection of CGRP-(8-37) (0.5 nmol/kg), a CGRP(1) receptor antagonist. To determine whether gene transfer of CGRP after SAH may prevent cerebral vasoconstriction, we constructed a virus with a cytomegalovirus (CMV) promoter, which results in rapid expression of the transgene product. Treatment of rabbits with AdCMVCGRP after experimental SAH prevented constriction of the basilar artery 2 days after SAH. Thus, gene transfer of CGRP prevents cerebral vasoconstriction in vivo after experimental SAH.

Stress and micromotion in the taper lock joint of a modular segmental bone replacement prosthesis

The stress distribution within the components and the micromotion of the interface significantly influence the long-term function of the taper lock joint in a modular segmental bone replacement prosthesis. Bending-induced gap opening between the cone and the sleeve can lead to an inflow of biological fluids, and thus accelerate implant corrosion. Local areas of high stress can also accelerate the corrosive processes and initiate local yielding, which may lead to a fracture in one of the components. In this study, a 3-D finite element (FE) model of a modular segmental bone replacement prosthesis was developed to study the interface micromotion and component stress distribution under the maximum loads applied during gait for a taper lock joint with multiple material combinations. Bending was the main cause of the local high stresses and interface separation within the taper joint. For Ti6A14V components, cortical bone bridging and ingrowth across the taper lock gap reduced the peak stress by 45% and reduced the contact interface separation by 55%. Such tissue formation around the taper lock joint could also form a closed capsule to restrict the migration of potential wear particles and thus prevent the biologic process of bone resorption induced by metal debris.

[Preventive and therapeutic effect of Chinese herbs naofeikang on experimental emphysema and pulmonary artery hypertension in hamsters]

OBJECTIVE

To observe preventive and therapeutic effect of Chinese herbs Naofeikang on hypoxic pulmonary artery hypertension of elastase-induced emphysema hamsters and investigate its mechanism.

METHODS

Hamsters for 30 days after intratracheally-instilled elastase, were kept in hypoxia environment under normal atmospheric pressure for 15 days, 50 hamsters were divided into prevention group (Prv), treatment group (T), emphysema + hypoxia (EH), and control group(N). Mean pulmonary artery pressure (MPAP) was measured before hamsters were killed. And then right ventricle hypertrophy index (RVHI) was measured, as well as circulating endothelial cells (CEC) and cells recoveries from bronchoalveolar lavage fluid (BALF) were counted. Meanwhile, pulmonary tissue changes were studied under light microscope with morphometric analysis.

RESULTS

Compared with EH group, MPAP, CEC, and cells recoveries of BALF of Prv and T groups were significantly decreased (P < 0.05 or P < 0.01); Mean linear intercept and percentage of arterial media area of Prv and T groups had totally a significant difference (P < 0.01) in comparison with EH group.

CONCLUSIONS

Chinese herbs Naofeikang could lower pulmonary hypertension, preserve vessel endothelial cells and lessen the inflammatory reaction in pulmonary tissue. Thereby, it could hinder the further development of emphysema and inhibit the remodeling of pulmonary small artery.

Deterin, a new inhibitor of apoptosis from Drosophila melanogaster

Deterin, a new apoptosis inhibitor from Drosophila melanogaster, possesses an unusual structure of only a single baculovirus inhibitor of apoptosis (IAP)-type repeat and no RING finger motif. The biochemical actions of deterin are demonstrated in SF9 and S2 cell transfection assays, in which the expressed protein acts in the cytoplasm to inhibit or deter cells from apoptosis otherwise induced by the caspase-dependent apoptosis activator reaper or by cytotoxicants. A loss of function phenotype for deterin of cell death was indicated by transfections with either a dominant negative deterin mutant or with inhibitory RNA (RNAi) for deterin. The dominant negative C-terminal fragment that antagonized antiapoptotic activity of deterin did not affect antiapoptotic activity of DIAP1 or p35. Both the baculovirus IAP-type repeat (BIR) domain and the alpha-helical C-terminal domain are necessary in both SF9 and S2 cells for deterin to manifest its activity to prevent cell death. The approximately 650-base deterin transcript is present in embryos, third instar larvae, and late stage nurse cells of adult females. The deterin transcript is distributed throughout early stage embryos, whereas in later stage embryos it becomes progressively restricted to the central nervous system and gonads. Whereas the nematode survivin-type IAP has thus far been implicated only as a mitotic regulator, Drosophila deterin constitutes the first invertebrate member of the survivin-type IAP group to exhibit apoptosis-inhibitory activity.

Interference of the simian virus 40 origin of replication by the cytomegalovirus immediate early gene enhancer: evidence for competition of active regulatory chromatin conformation in a single domain

Replication origins are often found closely associated with transcription regulatory elements in both prokaryotic and eukaryotic cells. To examine the relationship between these two elements, we studied the effect of a strong promoter-enhancer on simian virus 40 (SV40) DNA replication. The human cytomegalovirus (CMV) immediate early gene enhancer-promoter was found to exert a strong inhibitory effect on SV40 origin-based plasmid replication in Cos-1 cells in a position- and dose-dependent manner. Deletion analysis indicated that the effect was exerted by sequences located in the enhancer portion of the CMV sequence, thus excluding the mechanism of origin occlusion by transcription. Insertion of extra copies of the SV40 origin only partially alleviated the inhibition. Analysis of nuclease-sensitive cleavage sites of chromatin containing the transfected plasmids indicate that the chromatin was cleaved at one of the regulatory sites in the plasmids containing more than one regulatory site, suggesting that only one nuclease-hypersensitive site existed per chromatin. A positive correlation was found between the degree of inhibition of DNA replication and the decrease of P1 cleavage frequency at the SV40 origin. The CMV enhancer was also found to exhibit an inhibitory effect on the CMV enhancer-promoter driving chloramphenicol acetyltransferase expression in a dose-dependent manner. Together these results suggest that inhibition of SV40 origin-based DNA replication by the CMV enhancer is due to intramolecular competition for the formation of active chromatin structure.

Supplementation with L-histidine during dietary zinc repletion improves short-term memory in zinc-restricted young adult male rats

Zinc, an essential dietary element, modulates neurotransmission in brain regions associated with cognition. Cognitive dysfunction has been reported in offspring of female rats fed zinc-restricted diets during gestation and/or lactation. Studies on the cognitive effects of zinc restriction during young adulthood are limited. After a 3-wk period of dietary zinc restriction, male rats (71-75 d old) were repleted with zinc chloride alone, or zinc chloride supplemented with L-histidine, and short-term memory was measured using the Morris water maze. During restriction, zinc-restricted rats demonstrated significantly longer (86.0%) retrieval latencies than nonrestricted controls, and significantly lower liver (25.5%), bone (32.5%) and hippocampal (3.2%) zinc concentrations. During subsequent repletion, rats repleted with zinc chloride supplemented with L-histidine improved their retrieval latencies to the extent that they were no longer significantly different from controls by repletion d 3. This was associated with a return of hippocampal zinc concentrations to control values by repletion d 3. The mean retrieval escape latencies of the zinc chloride-repleted rats remained significantly prolonged (75.0%). Collectively, these data indicate the following: 1) feeding a zinc-restricted diet for 3 wk impairs short-term memory in young adult male rats, and 2) repletion with dietary zinc supplemented with L-histidine improves short-term memory function more efficiently than dietary zinc chloride alone. The latter point suggests that dietary zinc supplemented with L-histidine is more bioavailable to the brain than zinc provided as zinc chloride alone. These findings are important in that they highlight the importance of both dietary zinc formulation and the use of functional assessments in determining zinc nutriture.

[Study on clinical and laboratory features of preleukemia patients]

OBJECTIVE

To explore prospective diagnostic criteria for preleukemia.

METHODS

A case control study of the discrepancies of clinical and laboratory features between patients with preleukemia and those with chronic aplastic anemia (CAA) or atypical paroxysmal nocturnal hemoglubinuria (a-PNH).

RESULTS

There were eight variables of significance: (1) lymphocytoid micromegakaryocytes in marrow; (2) immature granulocytes in peripheral blood; (3) >or= 2% myeloblasts in marrow; (4) positive periodic acid schiff (PAS) staining of nucleated erythrocytes; (5) myeloid differentiation index >or= 1.8; (6) clonal karyotypic abnormalities; (7) negative sister chromatid differentiation; (8) > 4.0 cluster/colony ratio of granulocyte-macrophage colony-forming units (CFU-GM). The following criteria was assigned: A: To meet (1) and at least two of the other seven variables; B: To meet at least four of the eight variables. All of the patients with preleukemia met A or B and none of the patients with CAA or a-PNH did.

CONCLUSION

Preleukemia is different from CAA or a-PNH. It has its own clinical and laboratory features, which may be useful for prospective diagnosis.

[Changes of surfactant A and B in alveolar type II cells in hamster with elastase-induced emphysema]

OBJECTIVE

To observe the changes of surfactant A and B (SP-A and SP-B) in alveolar type II cells of lungs in hamsters with elastase-induced emphysema.

METHODS

After intratracheal instilling of elastase, hamsters were killed at the 30th, 60th and 90th day of the experiment respectively. Slides of lung tissue were examined under light microscope and measured by calculating the mean linear intercepts. Then the slides were stained under immunohistochemistry procedures and measured by using a morphometric analysis system. Meanwhile, slides were also checked by electron microscopy.

RESULTS

In comparison with the normal group, MLI of the elastase group was significantly increased (P < 0.01). Immunohistochemistry showed that the percentage of both SP-A and SP-B positive cells was significantly decreased 30 days after the intratracheal instilling of elastase (from 48.0% +/- 3.0% to 9.5% +/- 4.0% and from 28.0% +/- 4.0% to 13.3% +/- 4.1%, respectively; P < 0.01), however, a time-dependent recovery 90 days after instilling was seen. Electron microscopy showed a significantly decrease of the number of lamellae.

CONCLUSION

The decrease of SP-A and SP-B in alveolar type II cells seems to play an important role in the development of emphysema.

Gene therapy of hypertensive vascular injury

Hypertension and vascular injury usually require prolonged treatment, and compliance is a key to efficacy for pharmacologically-based antihypertensive therapy. Gene therapy has the potential to be long lasting, with few side effects. Recent studies have provided promising results, in which hypertension can be treated by either augmentation of vasodilation or inhibition of vasoconstriction through gene transfer in experimental models. Gene transfer is also becoming useful for the study of mechanisms of physiologic and pathophysiologic conditions, including hypertension. In this mini-review, we summarize some recent studies in this area of research, and suggest some areas where progress is needed to advance the research toward gene therapy.

Obtaining maximal optic nerve length during enucleation procedures

OBJECTIVE

To determine optimal scissor blade design and surgical approach to facilitate obtaining a long optic nerve segment during enucleation procedures.

METHODS

Two hundred mock enucleations were performed with the use of a human child skull model and a silicone sphere to simulate an eye. Temporal and nasal approaches with scissor blades with noncurved, mildly curved, or strongly curved blades were tested.

RESULTS

Longer optic nerve segments were obtained with mildly curved scissor blades from both temporal and nasal surgical approaches. Strongly curved scissor blades uniformly produced smaller specimens.

CONCLUSIONS

Mildly curved scissors should be used for enucleation when a long optic nerve specimen is desired. Strongly curved scissors should be avoided.

Lentiviral gene transfer to the nonhuman primate brain

Lentiviral vectors infect quiescent cells and allow for the delivery of genes to discrete brain regions. The present study assessed whether stable lentiviral gene transduction can be achieved in the monkey nigrostriatal system. Three young adult Rhesus monkeys received injections of a lentiviral vector encoding for the marker gene beta galatosidase (beta Gal). On one side of the brain, each monkey received multiple lentivirus injections into the caudate and putamen. On the opposite side, each animal received a single injection aimed at the substantia nigra. The first two monkeys were sacrificed 1 month postinjection, while the third monkey was sacrificed 3 months postinjection. Robust incorporation of the beta Gal gene was seen in the striatum of all three monkeys. Stereological counts revealed that 930,218; 1,192,359; and 1,501,217 cells in the striatum were beta Gal positive in monkeys 1 (n = 2) and 3 (n = 1) months later, respectively. Only the third monkey had an injection placed directly into the substantia nigra and 187,308 beta Gal-positive cells were identified in this animal. The injections induced only minor perivascular cuffing and there was no apparent inflammatory response resulting from the lentivirus injections. Double label experiments revealed that between 80 and 87% of the beta Gal-positive cells were neurons. These data indicate that robust transduction of striatal and nigral cells can occur in the nonhuman primate brain for up to 3 months. Studies are now ongoing testing the ability of lentivirus encoding for dopaminergic trophic factors to augment the nigrostriatal system in nonhuman primate models of Parkinson's disease.

Mechanisms of photoreceptor death and survival in mammalian retina

The mammalian retina, like the rest of the central nervous system, is highly stable and can maintain its structure and function for the full life of the individual, in humans for many decades. Photoreceptor dystrophies are instances of retinal instability. Many are precipitated by genetic mutations and scores of photoreceptor-lethal mutations have now been identified at the codon level. This review explores the factors which make the photoreceptor more vulnerable to small mutations of its proteins than any other cell of the body, and more vulnerable to environmental factors than any other retinal neurone. These factors include the highly specialised structure and function of the photoreceptors, their high appetite for energy, their self-protective mechanisms and the architecture of their energy supply from the choroidal circulation. Particularly important are the properties of the choroidal circulation, especially its fast flow of near-arterial blood and its inability to autoregulate. Mechanisms which make the retina stable and unstable are then reviewed in three different models of retinal degeneration, retinal detachment, photoreceptor dystrophy and light damage. A two stage model of the genesis of photoreceptor dystrophies is proposed, comprising an initial "depletion" stage caused by genetic or environmental insult and a second "late" stage during which oxygen toxicity damages and eventually destroys any photoreceptors which survive the initial depletion. It is a feature of the model that the second "late" stage of retinal dystrophies is driven by oxygen toxicity. The implications of these ideas for therapy of retinal dystrophies are discussed.

[The clinical implications of IgG subclass in 84 patients with autoimmune hemolytic anemia]

OBJECTIVE

To evaluate the clinical implications of IgG subclass in autoimmune hemolytic anemia(AIHA).

METHODS

Data of 84 AIHA patients were retrospectively analyzed.

RESULTS

In the 84 patients, IgG1 + IgG3 + C3d accounted for 45.0%, IgG1 + IgG3 15.5%, IgG1 + C3d 11.0%, C3d 10.7%, IgG1 9.5% and IgG3 + C3d 8.3%. IgG3 patients had the most severity of clinical and laboratory findings, followed by IgG1 patients. In IgG1 and IgG3 subgroups, the severity of hemolysis was positively correlated with the score of Coombs' test. The response rates of IgG3 and IgG1 patients were 68.2% and 100%, respectively.

CONCLUSION

In AIHA, the basic predominant IgG subclass is IgG1. IgG3 has a greater potential for red-cell destruction than IgG1 and C3d.