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D J Bond

Publications and source records attributed to D J Bond.

9 recordsLinked to original sources
PubMed1984

Dimethylsulfoxide induces aneuploidy in a fungal test system.

Errors in chromosome segregation leading to numerical anomalies appear to be unusually frequent in Man and consequently a large proportion of conceptions in our species are aneuploid. Concern has been expressed that this frequency may be increased still further following exposure to inducing substances (trisomigens) present in the environment. We have been developing a fungal test system to screen for such trisomigens and in this paper we report its use in detecting induction following exposure to dimethylsulfoxide (DMSO). In our system DMSO induces segregational errors at both the first and second meiotic division. The results also show that increases in aneuploidy are proportional to the underlying spontaneous frequency. If this finding is generally true it will be especially important to avoid exposure to trisomigens as Man might be especially vulnerable to them.

Aneuploidy↗
PubMed1979

Meiotic aneuploidy: its origins and induction following chemical treatment in Sordaria brevicollis.

A system suitable for the detection of meiotic aneuploidy is described in which various different origins of the aneuploidy can be distinguished. Aneuploid meiotic products are detected as black disomic spores held in asci containing all the products of a single meiosis. Aneuploidy may result from nondisjunction or from a meiosis in which an extra replica of one of the chromosomes has been generated in some other way, e.g., extra replication. By using this system it has been shown that pFPA treatment increase aneuploidy, primarily through an effect on nondisjunction. Preliminary results with trifluralin have indicated that this compound, too, may increase aneuploidy. There is a good possibility that the system can be further developed to permit a more rapid screening using a random plating method; this will allow a more efficient two-part analysis of the effects of compounds under test.

Aneuploidy↗
PubMed1974

Preferential ascus discharge during cross maturation in Sordaria brevicollis.

Crosses involving spore color mutants of Sordaria brevicollis all showed a decline in the frequency of second division asymmetric asci (2:2:2:2's) as the cross matured. This decline was due to the preferential maturation and/or discharge of these asci. The proportion of spindle overlap and recombinational asci within the group did not change as shown by ascus dissection. The preferential discharge was also found to occur in two-point crosses where the asci did not contain wild-type spores.

Alleles↗
PubMed1968

Recent history of ischaemic heart disease and duodenal ulcer in doctors.

Data are presented on the incidence of ischaemic (coronary) heart disease and duodenal ulcer among the several thousand male medical practitioners aged 35-64 holding immediate sickness benefit policies with the Medical Sickness Annuity and Life Assurance Society Limited. Three periods are considered: 1947-50, 1957-60, and 1961-5.The incidence of first clinical episodes of ischaemic heart disease in the doctors altered little between 1947-50 and 1957-60 but increased in 1961-5. Comparison of the late 1940s with the early 1960s shows a 60% rise of incidence at ages 45-54 but little change at other ages. Cases first presenting as "sudden" death increased between 1947-50 and 1961-5 by 111% at 45-54, and again changed little at 55-64. In two other occupational groups that have been studied-bus conductors and insurance salesmen-the increase of incidence was greater than for the doctors at 45-54 and it occurred also over 55 years of age. The increase from 1947-50 to 1961-5 in mortality during all episodes of ischaemic heart disease was the same in the doctors as in the male population of England and Wales at 45-54, but at 55-64 it was less.The results in the doctors are not due to alterations over the period in length of sickness absence, or underwriting policy, or of the nomenclature used on the certificates.Well-documented changes in the smoking habits of doctors may be partly responsible for what appears to have been a relatively favourable experience of ischaemic heart disease from 1947-50 to 1961-5, especially at ages 55-64.Incidence of duodenal ulcer at ages 35-64 declined steadily in this population of doctors from 1947-50 to 1961-5. The decline is very likely to be real.

Adult↗