Effects of surface potential on growth of ZnO nanorod arrays investigated by electric force microscopy.

The electric and Kelvin force probe microscopy were used to investigate the surface potentials on the ZnO seed layer, which shows a remarkable dependence on the annealing temperature. The optimum temperature for the growth of nanorod arrays normal to the surface was found to be at 600 degrees C, which is in the range of right surface potentials and energy measured between 500 degrees C and 700 degrees C. We demonstrated from both electric and Kelvin force probe microscopy studies that surface potential controls the growth of ZnO nanorods, illustrating the fact that this is a promising technique to visualize the control of ZnO nanorod arrays by studying their surface potentials. This study will provide important understanding of growth of other nanostructures.

Synthesis and magnetic characterizations of La(1-x)Sr(x)MnO3 nanoparticles for biomedical applications.

The La(1-x)Sr(x)MnO3 (LSMO) nanoparticles have been synthesized by citric gel process followed by ball milling method. These nanoparticles demonstrated high crystalline quality. Nanoparticle size was further decreased by ball milling technique as observed by the field-emission scanning electron microscopic studies. The ball milled and silica coated LSMO nanoparticles show magnetic transition at about 370 K with a superparamagnetic properties. The ferromagnetic resonance (FMR) spectra analysis of LSMO nanoparticles shows large FMR linewidth due to the surface strain of the nanoparticles. Both magnetization and FMR studies demonstrate that the LSMO nanoparticles are highly anisotropic. The toxicity of the nanoparticles was studied for safe biomedical applications. Measurement of intracellular reactive oxygen species (ROS) and MTT assay results show that LSMO nanoparticles are relatively nontoxic and the toxicity is further reduced by SiO2 coating. These results are very important for applications in the field of biotechnology.

Elevated concentrations of dopamine sulfate in plasma of cocaine abusers.

This study investigated the effect of cocaine abuse on peripheral catecholamines. Specifically, we measured the concentration of free dopamine, dopamine sulfate, free norepinephrine, norepinephrine sulfate, free epinephrine and epinephrine sulfate in plasma samples obtained from the blood of a group of patients with cocaine addiction (N = 15). The concentrations of free and sulfoconjugated catecholamines in plasma were measured by a radioenzymatic technique. The results of this study revealed significant (P < 0.0001) elevation in plasma dopamine sulfate (8926 +/- 1204 pg/mL) of cocaine addicts upon admission to an in-patient treatment facility when compared with the level of this dopamine metabolite in plasma of control subjects (2356 +/- 121 pg/mL). Furthermore, there was a significant (P < 0.0001) relationship between elevation in plasma dopamine sulfate levels and severity of cocaine use among these patients, and in the majority of cases the plasma levels of dopamine sulfate declined appreciably in time with abstinence from cocaine. In contrast, no appreciable difference was observed in the concentrations of either free or sulfate-conjugated norepinephrine and epinephrine in plasma of cocaine addicts as compared with controls. Differences in plasma dopamine sulfate among these patients versus controls may be interpreted as a reflection of activation of extracellular dopamine metabolism associated with chronic cocaine exposure in humans.

Comparative genomic hybridization in acute myeloid leukemia. A comparison with G-banding and chromosome painting.

Comparative genomic hybridization (CGH) represents a new technique for global analysis of a whole genome for net loss or gain of chromosome regions. It offers several advantages over alternative techniques. It permits analysis of a whole genome in a single hybridization reaction, it does not require the generation of metaphases from tumor cells, and it only requires very small numbers of tumor cells. Most previous studies have concentrated on the application of CGH to the analysis of chromosome defects associated with solid tumors. In this paper we report the use of CGH to study bone marrow samples from a patient with acute myeloid leukemia and complex karyotypic abnormalities. The results obtained using CGH were compared with G-banding analysis. Both G-banding and CGH detected a 5q deletion, a 7q deletion, additional material derived from 8q, and an HSR on 11q. However, several apparently discrepant results were also obtained. Paints for chromosomes 3, 5, 7, 8, 11, 12, 14, 17, 22, and X were therefore used to resolve these differences. Our results demonstrate that CGH detected chromosome abnormalities associated with acute myeloid leukemia and that CGH provided information that was not obtained by G-banding analysis alone. These data suggest that CGH may prove a useful adjunct to conventional cytogenetic and molecular analysis of hematologic malignancies.

Characterization of 20q deletions in patients with myeloproliferative disorders or myelodysplastic syndromes.

Deletions of the long arm of chromosome 20 are associated with several myeloid malignancies. We have analyzed the structure of the del(20q) in 30 patients and two cell lines. Twenty-one of the patients presented with a myeloproliferative disorder and nine with a myelodysplastic syndrome. Two categories of deletions were identified. Eighteen patients had a large deletion with loss of both G(+) bands from the long arm of chromosome 20. Twelve patients had small deletions with loss of one G(+) band from the long arm of chromosome 20. A chromosome paint was generated from a del 20q marker carrying a small deletion. This probe was hybridized to normal metaphases (reverse chromosome painting) and also to metaphases from patients with a del 20q (comparative reverse chromosome painting). All six small deletions analyzed were characterized by loss of the proximal G(+) band (q12) and retention of the distal G(+) band (q13.2). These data define a minimal deleted region extending from 20q11.2-20q13.1.

Assessment of angioplasty balloon catheters: further studies.

Eight millimetre diameter angioplasty balloon catheters of both the Gruntzig and Olbert types from five manufacturers have been tested in vitro to establish bursting pressures and the changes in maximum and deflated diameters following repeated inflations, both when free and within a restraining sleeve. Maximum inflated diameters were within 10% of that stated and all types of balloon except one burst at a pressure greater than the recommended value. Deflated diameters were approximately 1 mm greater than insertion diameters, which are much smaller in the Olbert type. All balloons became a little larger with each of the first few distensions, and became stiffer. The maximum diameter was reached and remained constant after 10-15 distensions. Distension within a latex sleeve did not change bursting pressures, and it is considered that results from unconstrained testing can be extrapolated to behaviour in vivo. Computer modelling and calculation of maximum stress resultants also showed that calculated longitudinal and circumferential stresses are unaffected by applied restrictions. It is concluded that balloon technology is steadily improving and it is suggested that British Standards should be established for dilatation balloon catheters. Amongst other factors these Standards should include maximum recommended inflation pressures that are at least 2 atm less than bursting pressures, whilst the stated maximum diameter should be for fully extended balloons, and should have a tolerance of more than +/- 10%.

A price index for biomedical research and development.

Price changes of goods and services used in biomedical research and development have important effects on the costs of conducting research. We summarize the trends suggested by a recently constructed biomedical research and development price index, which measures the effects of price changes on the inputs to biomedical research from 1979 to 1986. The fixed-weighted index uses fiscal year 1984 National Institutes of Health expenditure patterns in developing the weights. The rate of increase shown in the price index peaked in 1981 and slowed in following years. However, in most years, the rate of increase in the price index has exceeded the rate of increase in other major price indexes, such as the consumer price index, the producer price index, and the Gross National Product fixed-weighted price index.

The effect of cocaine abuse on plasma levels of sulfated dopamine and salsolinol in alcoholics.

This study investigated the effect of cocaine abuse on peripheral dopamine and its tetrahydroisoquinoline metabolite salsolinol in chronic alcoholics. Specifically, the concentration of dopamine sulfate and salsolinol sulfate was measured in plasma samples obtained from the blood of a group of alcoholics (n = 40) and alcoholics with cocaine dependence (n = 55). The concentrations of sulfoconjugated dopamine and salsolinol were measured by a radioenzymatic technique. The results of this study showed that chronic alcoholics (627 +/- 195 pg/ml) and alcoholics with cocaine addiction (409 +/- 76 pg/ml) had significantly (p < 0.05) elevated levels of salsolinol sulfate (mean +/- SEM) in their plasma as compared to controls (99.5 +/- 7.5 pg/ml). However, alcoholics with cocaine dependence produced significantly (p < 0.01) higher concentration of dopamine sulfate in their plasma (7520 +/- 1299 pg/ml) as compared to chronic alcoholics (3896 +/- 438 pg/ml) and controls (2124 +/- 104 pg/ml). Differences in plasma dopamine sulfate among alcoholics with cocaine dependence vs. alcoholics without cocaine dependence may be interpreted as a reflection of increased extracellular dopamine metabolism associated with chronic cocaine exposure.

Synthesis and mutagenicity of a series of nitrated carbazoles and hydroxycarbazoles.

Nitrated derivatives of the aza-arenes carbazole and 2-hydroxycarbazole were synthesized and tested for mutagenicity in the Ames plate-incorporation assay. 3,6-Dinitrocarbazole was the most mutagenic towards Salmonella typhimurium strain TA98 (> 100 revertants/micrograms, 25 revertants/nmol, with or without S9) followed by 2-hydroxy-1,3,6-trinitrocarbazole (24 revertants/micrograms, 7 revertants/nmol without S9) and 2-hydroxy-3-nitrocarbazole (27 revertants/micrograms, 6 revertants/nmol without S9). 2-Hydroxy-1,3-dinitrocarbazole, 1,6-dinitrocarbazole, 3-nitrocarbazole and 1-nitrocarbazole ranged from moderately to weakly active (7-1 revertants/micrograms, 2-0.3 revertants/nmol without S9). Carbazole and 2-hydroxycarbazole, and 2-hydroxy-1-nitrocarbazole, were quite inactive. Activity was generally decreased by the presence of S9, except for the dinitrocarbazoles, and was also lower in the variant TA98NR, indicating that mutagenicity was largely dependent on the presence of the 'classical' bacterial nitroreductase. The relative activities of these compounds are consistent with the hypothesis that structural features (orientation of the nitro group relative to the plane and to the long axis of the molecule, and ability to resonance-stabilize the positive charge on the arylnitrenium active electrophile intermediate) are major influences determining mutagenic potency of nitrated compounds.

Philadelphia-negative chronic myeloid leukaemia: detection by FISH of BCR-ABL fusion gene localized either to chromosome 9 or chromosome 22.

Dual-colour FISH has been used to study two patients with chronic myeloid leukaemia (CML) associated with a normal karyotype. Co-localization of signals from BCR and ABL cosmids was observed in interphase nuclei from both patients. In one patient, analysis of metaphase spreads showed that the 3' region of the ABL gene was deleted from one chromosome 9 and inserted into chromosome 22. In a second patient 5' BCR sequences were missing from one copy of chromosome 22, and co-localized with 3' ABL sequences on chromosome 9. These results demonstrate the molecular heterogeneity of Ph-negative CML. In addition, they illustrate the potential usefulness of dual-colour FISH on interphase nuclei for monitoring the response to treatment of patients with Ph-negative CML.

Platelet monoamine oxidase activity in alcoholics, alcoholics with drug dependence, and cocaine addicts.

The main objective of this investigation was to study the influence of drug dependence on platelet monoamine oxidase (MAO) activity in the presence and absence of alcoholism. One hundred and thirteen admissions to alcohol and drug treatment facilities participated in the study. Twenty-six met the criteria for alcoholism (group I), seventy-eight subjects were alcohol-/cocaine- and cannabis-dependent (group II), and the remaining nine were patients with DSM-III-R diagnosis of cocaine addiction (group III). MAO activity was assayed radiochemically with [14C]tyramine as a substrate (221 microM). The results of this study showed that platelet MAO activity [nmol of product formed x (mg protein)-1 x hr-1] (mean +/- SE) was significantly (p < 0.01) lower in all of these subjects (group I, 5.50 +/- 0.80; group II, 3.90 +/- 0.50; group III, 4.3 +/- 1.60) as compared with controls (14.85 +/- 1.13). Measurements of platelet MAO activity may provide us with a reliable biochemical marker for alcoholism and perhaps addiction to other substances of abuse (i.e., cocaine).

Detection of chromosome 20q deletions in bone marrow metaphases but not peripheral blood granulocytes in patients with myeloproliferative disorders or myelodysplastic syndromes.

Myeloproliferative disorders and myelodysplastic syndromes arise in multipotent progenitors and may be associated with chromosomal deletions that can be detected in peripheral blood granulocytes. We present here seven patients with myeloproliferative disorders or myelodysplastic syndromes in whom a deletion of the long arm of chromosome 20 was detectable by G-banding and/or fluorescence in situ hybridization in most or all bone marrow metaphases. However, in each case, microsatellite polymerase chain reaction (PCR) using 15 primer pairs spanning the common deleted region on 20q showed that the deletion was absent from most peripheral blood granulocytes. The human androgen receptor clonality assay was used to show that the vast majority of peripheral blood granulocytes were clonal in all four female patients. This represents the first demonstration that the 20q deletion can arise as a second event in patients with pre-existing clonal granulopoiesis. Microsatellite PCR analysis of whole bone marrow from two patients was consistent with cytogenetic studies, a result that suggests that cytogenetic analysis was not merely selecting for a minor subclone of cells carrying the deletion. Furthermore, in one patient, the deletion was present in both erythroid and granulocyte/monocyte colonies. This implies that the absence of the deletion in most peripheral blood granulocytes did not reflect lineage restriction of the progenitors carrying the deletion but may instead result from other selective influences such as preferential retention/destruction within the bone marrow of granulocytes carrying the deletion.

B-cell non-Hodgkin's lymphoma cell line (Karpas 1106) with complex translocation involving 18q21.3 but lacking BCL2 rearrangement and expression.

A B-cell non-Hodgkin's lymphoma (B-NHL) cell line (Karpas 1106) with an unusual three-way translocation involving 18q21.3 has been derived from a patient with mediastinal lymphoblastic B-NHL. Although conventional cytogenetics showed a derivative 18q-identical to that seen in cases with t(14;18)(q32.3;q21.3), no translocations of either chromosome 14 could be detected. Instead fluorescent in situ hybridization analysis using a chromosome-18 paint showed that the segment 18q21.3-18qter had become sandwiched on a derivative chromosome X between segments Xqter-c-Xq28 and 13q12-qter, with the centrometric site of 18q21.3 subband juxtaposed to the X sequences. Pulsed-field DNA blots failed to detect rearrangement of the BCL2 gene. Conventional DNA blots using a variety of restriction digests and both 5' and 3' BCL2 and FVT 1 probes also failed to detect rearrangement in Karpas 1106. A rearranged fragment seen only in HindIII digests with 5' BLC2 probes may represent a local microalteration, which is either a mutation or small deletion involving the HindIII site as seen in other cases of B-NHL. Neither BCL2 RNA nor BCL2 protein expression were detected. These and other data suggest that genes at 18q21.3, other than BCL2 and FVT1, may be targets for translocation in certain subgroups of B-NHL.

A recombination event that redefines the Huntington disease region.

We report both a recombination event that places the Huntington disease gene proximal to the marker D4S98 and an extended linkage-disequilibrium study that uses this marker and confirms the existence of disequilibrium between it and the HD locus. We also report the cloning of other sequences in the region around D4S98, including a new polymorphic marker R10 and conserved sequences that identify a gene in the region of interest.