Isolation of P multocida F-3, 4 from a stillborn snow leopard.
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Animals↗
Biomedical subjects
A Chatterjee
Publications and source records attributed to A Chatterjee.
Personality changes in Alzheimer's disease.
How personality changes in Alzheimer's disease is not well understood. Accentuations of premorbid personality, systematic shifts in personality traits, and specific personality changes affecting subtypes of patients have been postulated. To investigate which of these alternatives occurs in Alzheimer's disease, caregivers were given a comprehensive personality inventory standardized for use by informants. Caregivers observed more neurotic, less extroverted, and less conscientious behavior. To a smaller extent, patients with Alzheimer's disease were reported as becoming less agreeable and less open. The changes in reports of neuroticism, extroversion, agreeableness, and openness suggested consistent systematic shifts across all patients. Patients with depressive features were reported to have been more neurotic; those with paranoid delusions were reported as having been more hostile. Premorbid personality traits may predispose to subsequent psychiatric symptoms in Alzheimer's disease.
Aged↗
Search patterns and neglect: a case study.
An irregular and unsystematic search pattern may contribute to unilateral neglect. We examined the sequence of cancellations performed by a patient with unilateral neglect and found that she followed a systematic and stereotypic vertical search pattern. To overcome this vertical search pattern, foils were placed in rows. These foils induced slightly more horizontal movements, but did not alter her neglect. In another attempt to overcome her vertical search and tendency to cancel on the right, she was explicitly instructed to cancel targets alternating to and from the right and left sides of the array. This strategy overcame her vertical search, but, instead of modifying the severity of her neglect, this task only changed its spatial distribution. The altered spatial distribution of neglect is difficult to reconcile with current theories of neglect. We suggest that this patient demonstrates a limited capacity to sequentially be aware of or act upon stimuli.
Aged↗
A stimulus-response relationship in unilateral neglect: the power function.
We have previously suggested that patients with unilateral neglect may be limited in their ability to sequentially attend or act upon stimuli. To assess the nature of this capacity limitation, we examined the relationship between number of stimuli presented on cancellation arrays and how many targets a patient with neglect cancelled. This relationship was systematic and described by a power function: targets cancelled = K (targets presented)B, in which the constant and exponent were derived empirically. Density of targets and time taken to cancel targets did not account for the relationship. Improvement on subsequent testing was reflected in an increase in the constant. However, the exponent of the power function did not change, suggesting that some critical aspect of her dysfunction remained the same. These data also imply that she had implicit knowledge of quantity of stimuli presented, and that this knowledge systematically influenced her explicit behavior.
Aged↗
Amnesia following a discrete basal forebrain lesion.
Destructive lesions of the basal forebrain are associated with memory impairment in both humans and experimental animals. The basal forebrain is thought to contribute to memory function by providing cholinergic innervation to critical memory structures such as the hippocampus and amygdala. In previously reported clinical cases of basal forebrain amnesia, multiple neuroanatomical regions have been damaged, preventing identification of the minimal critical lesion necessary to produce an amnestic syndrome. We describe a patient who developed persistent, global anterograde and retrograde amnesia following resection of a low-grade glioma. Post-surgical magnetic resonance imaging studies revealed a small discrete lesion, centred in the right diagonal band of Broca, that included the preoptic area, the anterior hypothalamus, the lamina terminalis and the paraterminal gyrus. The septal nuclei and the cell bodies of the nucleus basalis of Meynert appeared to have been spared, as were other structures in the medial temporal lobe and diencephalon. Our case provides critical support for the independent contribution of the basal forebrain, in particular the diagonal band nuclei, in memory function. We propose that our patient's amnesia resulted from disconnection of pathways between the diagonal band nuclei and the hippocampal region, depriving the hippocampus of cholinergic innervation.
Amnesia↗
How little luteal tissue of rats is needed to maintain pregnancy till term--an experimental verification.
Surgical reduction of luteal tissue to about 20% of its total mass on day 5 pc was found to maintain gestation till term. A high degree of fetal loss was, however, evident. An identical surgical manipulation at the end of maximal luteal maturity, that is, on day 16 pc, resulted in normal maintenance of gestation. Fetal growth and their survival rate were found to be comparable to controls. An exclusive surgical extirpation of corpora lutea, on the other hand, either on day 16, 17, 18 or 19 was found to cause 100% fetal loss by day 23. However, progesterone replacement therapy concurrently with surgical luteal ablation till day 20, or surgical extirpation of the entire luteal mass when shifted on day 20, led the pregnancy to term. Present experimental findings, therefore, suggest that only about 20% of the functionally matured luteal mass until day 20 is essentially enough to maintain an ideal pregnancy status till term.
Animals↗
Cranial computed tomographic observations in multi-infarct dementia. A controlled study.
BACKGROUND AND PURPOSE: We compared cranial computed tomography findings among 58 multi-infarct dementia index cases and 74 multi-infarct control subjects without cognitive impairment to identify potential determinants of multi-infarct dementia. METHODS: The cranial computed tomography records of acute ischemic stroke patients with a history of multiple cerebral infarcts were compared to determine the number, location, and size of cerebral infarcts; the pattern of infarction; brain volume loss; and the degree of white matter lucency, sulcal enlargement, and ventricular enlargement. Multi-infarct patients were divided into two groups: 1) index cases were defined as those with multi-infarct dementia as defined by the Diagnostic and Statistical Manual of Mental Disorders, edition 3 (DSM-III) criteria; and 2) control subjects were defined as those multi-infarct patients without dementia or multi-infarct dementia according to DSM-III criteria. RESULTS: Overall, multi-infarct index cases had more cerebral infarcts, more cortical and subcortical left hemisphere infarcts, higher mean ventricular volume to brain volume ratio, more extensive enlargement of the body of the lateral ventricles and cortical sulci, and a higher prevalence of white matter lucencies. Among multi-infarct cases and control subjects the most frequent site of infarction was the subcortical region, and the most frequent pattern of infarction was lacunar. Stepwise logistic regression analysis examined cranial computed tomography as well as other factors and showed that level of education, stroke severity, left cortical infarction, and diffuse enlargement of the left lateral ventricle were the best overall predictors of multi-infarct dementia. CONCLUSIONS: Level of education, stroke severity, and left hemisphere infarction may be predictors of multi-infarct dementia.
Brain↗
Environmental pollution and chronic arsenicosis in south Calcutta.
Careless handling of industrial wastes often creates problems for human health and the environment. Chronic arsenic toxicity, resulting from household use of arsenic-contaminated water occurred in 53 out of 79 members (67%) of 17 families residing in South Calcutta close to a factory that manufactured Paris-green (copper acetoarsenite). Clinical investigation of 20 of these affected persons showed typical skin pigmentation as well as palmar and plantar keratosis in all of them, while gastrointestinal symptoms, anaemia and signs of liver disease and peripheral neuropathy were seen in many. The water used by the affected families for drinking and cooking had been taken from shallow tubewells and had arsenic levels from 5.0 to 58 mg/l (WHO permissible limit, 0.05 mg/l). Other residents in the same area whose drinking-water came from deep tubewells or from tap water supplied by the Calcutta Municipal Corporation (arsenic levels, less than 0.05 mg/l) were not affected. The study confirms that arsenic in the shallow tubewells was due to the waste discharged by the factory producing Paris-green.
Adolescent↗
Induction and turnover of catfish (Heteropneustes fossilis) metallothionein.
Induction of metallothionein by cadmium in catfish was a dose-dependent, transcriptionally-controlled process. Metallothionein mRNA was detected after Cd-exposure. Chronic doses produced more metallothionein than a single acute dose. Zn and Cu induced metallothionein to a lower extent compared to Cd. A few other low molecular weight proteins were induced in cadmium-exposed catfish liver, besides metallothionein. Isoelectric point of catfish metallothionein was 3.9. The rate of depletion of Cd and metallothionein was very slow from liver and almost unchanged from kidney following its induction by cadmium.
Animals↗
Purification of a group of HeLa nuclear proteins that bind to a regulatory element (-1430/-1327) of the human proliferating cell nucleolar protein P120 gene.
A group of proteins was purified from HeLa nuclear extract by DNA affinity chromatography which bind to an important regulatory element (-1430/-1327) of the P120 gene. The DNA binding activity was enriched 1075 fold. By silver staining three major polypeptides (50, 40, 37 kDa) were detected in the purified fraction. The band shift assay and the southwestern assay showed that the 50 kDa protein (P50) binds to the F1 (-1430/-1327) DNA fragment. The binding specificity of the group of proteins with F1 DNA in the presence of non-specific competitor DNA is much higher than that of P50 alone. On the basis of molecular weight and specific antibody binding, the 37 kDa protein appears to be the B23 nucleolar protein.
Amino Acids↗
Early chemical events and initial DNA damage.
Early chemical events (between 10(-15) and 10(-6) seconds) as they relate to the evolution of damage in radiation biology have been described in terms of a theoretical model. DNA is the target of concern in this model, and both indirect and direct effects have been explicitly accounted for in evaluating yields of strand breaks. In the indirect-effect considerations, a quantitative estimation of the time decay of water radical species--beginning with their production at 10(-14) seconds and leading to the interactions of hydroxyl radicals with DNA--has been a major focus. A method based on stopping-power theory and the Bragg rule has been described to account for direct effects. However, no attempt is made to follow all the chemical events that take place between the creation of initial (10(-6) seconds) damage and the observable strand break yields. The theoretical calculations refer to a simple aqueous system containing DNA molecules and scavenger (Tris). The theoretical results of strand break yields by different heavy charged particles are in good agreement with experimental cellular data under conditions of minimal enzymatic repair.
DNA↗
Characterization of products formed during the autoxidation of beta-carotene.
The anticarcinogenic action of carotenoids such as beta-carotene has been frequently ascribed to their antioxidant properties. However, very little is actually known about the nature of the antioxidant reaction or the products that are formed. beta-Carotene was exposed to either spontaneous autoxidation conditions or to radical-initiated autoxidation conditions. The products were separated by reverse-phase HPLC, and individual peaks were characterized with an on-line diode array detector. Carbonyl products were isolated and characterized by several procedures, including borohydride reduction to the corresponding alcohols, derivatization with O-ethyl-hydroxylamine to the corresponding O-ethyl-oximes of the carbonyls, and analysis by GC-MS. Under the conditions of the experiments, the formation of a homologous series of carbonyl products was demonstrated, including beta-apo-13-carotenone, retinal, beta-apo-14'-carotenal, beta-apo-12'-carotenal, and beta-apo-10'-carotenal. Several very hydrophobic compounds were formed, which have not been previously identified. In addition, the products of NaOCl-treatment of beta-carotene were analyzed, and shown to be significantly different from the autoxidation products. This type of product analysis should be useful in determining the nature of the oxidants reacting with beta-carotene in vivo.
Antioxidants↗
Nucleotide sequence and molecular characterization of pnlA, the structural gene for damage-inducible pectin lyase of Erwinia carotovora subsp. carotovora 71.
In a previous study, pnlA (the DNA damage-inducible structural gene for pectin lyase) of Erwinia carotovora subsp. carotovora 71 was localized to a 1.4-kb DNA segment within a 3.4-kb EcoRI fragment (J. L. McEvoy, H. Murata, and A. K. Chatterjee, J. Bacteriol. 172:3284-3289, 1990). We present here DNA sequence data for a 2.2-kb region revealing an open reading frame of 870 bases, corresponding to a protein (Pnl) of an approximate molecular mass of 32,100 Da and an isoelectric point of 9.92. Although initiation of translation is presumed to occur at the ATG codon, direct protein sequencing revealed alanine as the N-terminal amino acid, probably as a consequence of posttranslational removal of the initiating amino acid. The sequence of the first 20 amino acid residues of Pnl, purified from E. carotovora subsp. carotovora 71, agreed completely with the predicted amino acid sequence of the N-terminal segment. This finding also indicated that Pnl is not subject to processing by a signal peptidase. The transcriptional start site of pnlA was determined to reside 80 bp upstream of the translational start site. Deletion analysis revealed that 218 bp of DNA upstream of the transcriptional start site is sufficient for induction of pnlA by mitomycin C. Within 600 bp upstream of the translational start site, no sequences resembling a LexA binding site (SOS box) or a cyclic AMP receptor protein binding site were found. However, palindromic sequences were detected at -187 and -86 bp relative to the translational start site, and these could be potential sites for the binding of a regulatory protein(s). Comparison of the deduced amino acid sequence for PnlA with that of a Pnl from Aspergillus niger and with those of various pectate lyases of Erwinia species revealed a low degree of homology dispersed throughout the length of the proteins.
Amino Acid Sequence↗
Measurements of nucleic bases released after gamma irradiation of DNA in solution in air.
The release of unaltered nucleic bases from gamma-irradiated DNA in a dilute buffered aqueous solution was studied in both salmon sperm and superhelical viral DNA. Analyses of freed bases were made by high-performance liquid chromatography. An elution protocol was developed for maximum separation of the four nucleic bases and nucleosides with a sensitivity of 10-20 pmol of nucleic base. It was found that: (i) both prompt and delayed release of bases postirradiation occur in both types of DNA; (ii) these yields (G-values) were measured to be 10-15 times higher for the salmon sperm DNA in comparison to the SV40 DNA; (iii) the A-T/G-C ratio in the DNA was not reflected in the ratios of the released base; and (iv) based on measurements made by us of DNA strand breaks in SV40 DNA (unpublished results), less than half of all breaks result in the release of an undamaged base.
Adenine↗
Comparison of the immunological properties of mammalian (rodent), bird, fish, amphibian (toad), and invertebrate (crab) metallothioneins.
Immunoassays such as rocket immunoelectrophoresis, western dot blot hybridization, and competitive ELISA analysis were used to estimate and compare homology among fishes (several species), crab, toad, chicken and rodent metallothioneins. The relative abundance of tissue-specific metallothionein in catfish was highest in liver followed by kidney and pancreas like mammalian systems. Immunologically, considerable homology exists among fish metallothioneins, although the extent of homology differs to some extent. No homology was found between fish or chicken metallothioneins. The amphibian (toad) and invertebrate (crab) metallothioneins showed only partial homology with fish metallothioneins in antigenic determinants.
Amphibians↗
The formation of strand breaks in DNA after high-LET irradiation: a comparison of data from in vitro and cellular systems.
This paper presents a summary of our understanding to date of the formation of DNA strand breaks induced by highly energetic particle beams (high-LET radiation). We have compared our own recent data on the formation of strand breaks induced in DNA in an aqueous solution with our previous data and those of others available from the literature for similar lesions made in cellular DNA. When the strand break induction frequency, as number of breaks per Gy per unit DNA, is plotted against LET, a series of biological effect curves (one for each particle atomic number Z) is obtained. The frequency of the formation of single-strand breaks has an RBE of less than 1 for DNA in solution and for DNA in the cell; the frequency of the formation of double-strand breaks (dsb) also has an RBE of less than 1 for DNA in a solution containing low amounts of free radical scavenger(s), while the RBE can be greater than 1 in the 50-200 keV/microns range for cellular DNA. RBE values are with respect to X-rays or cobalt gamma-rays. In cells the level of unrejoined strand breaks is also highest in the 50-200 keV/microns range and may reach 25-35% of the initial break yield depending on particle energy and Z-value. These irreparable lesions include double-strand scissions and some form(s) of single-strand breaks. The data presented cover results obtained for helium to uranium particles, with an LET range of 16 to 160,000 keV/microns. When different biological end-points are compared a strong correlation is found between induction of dsb, chromosomal abnormalities and mutation induction.
DNA↗
Characterization of transposon insertion out- mutants of Erwinia carotovora subsp. carotovora defective in enzyme export and of a DNA segment that complements out mutations in E. carotovora subsp. carotovora, E. carotovora subsp. atroseptica, and Erwinia chrysanthemi.
Soft-rotting Erwinia spp. export degradative enzymes to the cell exterior (Out+), a process contributing to their ability to macerate plant tissues. Transposon (Tn5, Tn10, Tn10-lacZ) insertion Out- mutants were obtained in Erwinia carotovora subsp. carotovora 71 by using plasmid and bacteriophage lambda delivery systems. In these mutants, pectate lyases, polygalacturonase, and cellulase, which are normally excreted into the growth medium, accumulated in the periplasm. However, localization of the extracellular protease was not affected. The Out- mutants were impaired in their ability to macerate potato tuber tissue. Out+ clones were identified in a cosmid library of E. carotovora subsp. carotovora 71 by their ability to complement mutants. Localization of cyclic phosphodiesterase in the periplasm indicated that the Out+ plasmids did not cause lysis or a nonspecific protein release. The Out+ derivatives of the E. carotovora subsp. carotovora 71 mutants regained the ability to macerate potato tuber tissue. Our data indicate that a cluster of several genes is required for the Out+ phenotype. While one plasmid, pAKC260, restored the Out+ phenotype in each of the 31 mutants of E. carotovora subsp. carotovora, E. carotovora subsp. atroseptica, and Erwinia chrysanthemi, it failed to render Escherichia coli export proficient. Homologs of E. carotovora subsp. carotovora 71 out DNA were detected by Southern hybridizations in subspecies of E. carotovora under high-stringency conditions. In contrast, E. chrysanthemi sequences bearing homology to the E. carotovora subsp. carotovora 71 out DNA were detectable only under low-stringency hybridization. Thus, although the out genes are functional in these two soft-rotting bacterial groups, the genes appear to have diverged.
Biological Transport↗
Effect of gamma-irradiation of Escherichia coli on cyclic AMP binding activity.
Cyclic AMP binding in the extract of E. coli was taken as a measure of cAMP receptor protein (CRP) present in the cells. The gamma-irradiation of cells caused a dose-dependent inhibition of cAMP binding activity indicating that CRP gene is affected by gamma-irradiation. The binding activity in cells irradiated with 240 Gy gamma-ray dose remained unaltered by post-irradiation incubation. This supports previous finding that the enhanced inhibition of the L-arabinose isomerase synthesizing capacity, following incubation of gamma-irradiated cells at higher doses, must be due to a different cause than the catabolite repression.
Cyclic AMP↗