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M Gillman

Publications and source records attributed to M Gillman.

26 records · Page 2Linked to original sources
PubMed1989

Environmental significance of the potential for mer(Tn21)-mediated reduction of Hg2+ to Hg0 in natural waters.

The role of mer(Tn21) in the adaptation of aquatic microbial communities to Hg2+ was investigated. Elemental mercury was the sole product of Hg2+ volatilization by freshwater and saline water microbial communities. Bacterial activity was responsible for biotransformation because most microeucaryotes did not survive the exposure conditions, and removal of larger microbes (greater than 1 micromole) from adapted communities did not significantly (P greater than 0.01) reduce Hg2+ volatilization rates. DNA sequences homologous to mer(Tn21) were found in 50% of Hg2+-resistant bacterial strains representing two freshwater communities, but in only 12% of strains representing two saline communities (the difference was highly significant; P less than 0.001). Thus, mer(Tn21) played a significant role in Hg2+ resistance among strains isolated from fresh waters, in which microbial activity had a limited role in Hg2+ volatilization. In saline water environments in which microbially mediated volatilization was the major mechanism of Hg2+ loss, other bacterial genes coded for this biotransformation.

Animals↗
PubMed1989

Hybridization of DNA probes with whole-community genome for detection of genes that encode microbial responses to pollutants: mer genes and Hg2+ resistance.

Nucleic acids extracted from microbial biomass without prior culturing were hybridized with probes representing four mer operons to detect genes encoding adaptation to Hg2+ in whole-community genomes. A 29-fold enrichment in sequences similar to the mer genes of transposon Tn501 occurred during adaptation in a freshwater community. In an estuarine community, all four mer genes were only slightly enriched (by three- to fivefold), suggesting that additional, yet uncharacterized, mer genes encoded adaptation to Hg2+.

Adaptation, Physiological↗
PubMed1988

New vistas in chronic schizophrenia.

In view of the distinct possibility that the disturbed glucose regulation in the frontal area and basal ganglia of chronic schizophrenia is very germane to the successful treatment of this condition, a survey is given of the many factors that have to be considered in developing a therapy that takes into account this new information. The suggestion is made that the balance between cAMP and cGMP in the cells affected are dysregulated so that there is an excessive activity of the cAMP generating system which eventually leads to the pathological picture found in this condition. To restore the normal metabolic balance, use will have to be made of the various substances that are known to enhance the cGMP generating system in the cell, thereby restoring a more normal metabolic integrity. In this connection, the use of high doses of insulin under cover of hyperglycaemia and also the addition of D-ribose could become the cornerstone of a series of treatments to enhance the action of currently used medications in this often intractable illness.

Acute Disease↗
PubMed1982

Medicinal arsenic and internal malignancies.

A mortality analysis has been carried out on a cohort of patients given Fowler's solution (potassium arsenite) for periods ranging from 2 weeks to 12 years between 1945 and 1969. An excess of fatal and non-fatal skin cancer was apparent, but there was no overall excess mortality from cancer. Further analyses by site of cancer, dose level, and time from first exposure are also presented. A subset of patients were examined in 1969-70 for the presence of arsenical keratoses, hyperpigmentation and skin cancer. About half the patients had one or more of these signs. Although the cancer mortality of this entire subgroup was similar to the expected value, all the cancer deaths occurred in patients with prior signs of arsenicism. These data suggest that while any excess of internal malignancy due to the use of Fowler's solution is small or non-existent, there may be a susceptible subgroup which can be identified from dermatological manifestations.

Adult↗
PubMedDate not supplied

Determination of diarrheic shellfish toxins in mussels by microliquid chromatography-tandem mass spectrometry.

A fast, sensitive, and specific procedure for determining toxins that cause diarrheic shellfish poisoning (DSP) using microliquid chromatography coupled with tandem mass spectrometry (micro-LC-MS-MS) is reported. The lipophylic polyether acidic toxins okadaic acid (OA), its isomer dinophysistoxin-2 (DTX-2), the 35-methylokadaic acid dinophysistoxin-1 (DTX-1), and the novel toxin dinophysistoxin-1B (DTX-2B; recently isolated from Irish mussels) were extracted from shellfish tissues with acetone and chromatographed by isocratic elution at 10 microL/min with CH3 CN-H2O, 80 + 20 (v/v), containing 0.1% trifluoroacetic acid, through a C18 reversed-phase column (1.0 mm id). The chromatograph is coupled via an ion spray interface to an atmospheric pressure ionization source. Collision-induced-dissociation (CID) ion mass spectra of the protonated molecule, [M + H]+, at m/z 805 for OA, DTX-2, and DTX-2B and at m/z 819 for DTX-1, were obtained in MS-MS experiments to identify 2 diagnostic fragment ions for each analyte that could be used for selected-reaction-monitoring (SRM) micro-LC-MS-MS analysis. The CID spectrum of DTX-2B confirmed it to be a new OA isomer, like DTX-2. Standard curves obtained by SRM micro-LC-MS-MS were linear (r2 > or = 0.9992) over the range 0.05-1.00 micrograms/mL (i.e., 0.10-2.00 micrograms toxin/g hepatopancreas), and a detection limit of 15 pg/injection was obtained for each DSP toxin. Average recoveries ranged from 95 to 101%, and coefficients of variation ranged from 1.8 to 3.4%. This novel SRM micro-LC-MS-MS method was used to confirm acidic DSP toxins in Irish and Italian toxic mussels. It offers a high degree of specificity because analyte confirmation is based on retention time, molecular weight, structural information obtained from the presence of 2 diagnostic fragments for each analyte, and ion ratios. OA was found in both Irish (< or = 0.7 micrograms/g hepatopancreas) and Italian (< or = 1.5 micrograms/g hepatopancreas) mussels. DTX-1 was found only in Italian mussels (< or = 0.3 micrograms/g hepatopancreas). DTX-2 (< or = 6.1 micrograms/g hepatopancreas) and DTX-2B (< or = 0.08 micrograms/hepatopancreas) were unique to Irish shellfish.

Animals↗