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I Nicholson

Publications and source records attributed to I Nicholson.

30 records · Page 2Linked to original sources
PubMed1993

HLA DR4 is associated with the development of multiple basal cell carcinomas and malignant melanoma.

An association between HLA DR4 and the development of multiple basal cell carcinomas (BCC) and malignant melanoma (MM) was detected in southern Australia. There were highly significant differences in HLA DR frequencies between patients with multiple BCCs and MM and matched patients with multiple BCCs only. These findings suggest that hereditary factors associated with the HLA system influence what types of multiple skin cancers people develop.

Adult↗
PubMed1993

Prognostic significance of detection of monoclonality in remission marrow in acute lymphoblastic leukemia in childhood. Australian and New Zealand Children's Cancer Study Group.

Techniques based on the polymerase chain reaction (PCR) to detect rearrangement of the immunoglobulin or T-cell receptor genes can detect residual disease in leukemia and hence have the potential to improve prognosis and treatment. Such techniques may involve either detection of monoclonality, which is simple and quick but has limited sensitivity, or specific detection of the leukaemic clone, which is complex and time-consuming but has high sensitivity. The PCR was used to detect monoclonal rearrangements of the immunoglobulin heavy chain and/or T-cell receptor gamma chain genes in archival marrow specimens from 185 children with acute lymphoblastic leukemia who achieved remission during two consecutive Australasian trials of treatment. A monoclonal rearrangement was detected at diagnosis in 152 (84%) patients and in these patients detection of the same rearrangement in the remission marrow at the end of induction therapy was highly significantly correlated with outcome. There were nine patients in whom polymerase chain reaction showed only the monoclonal rearrangement and eight (89%) relapsed; there were 26 patients in whom PCR showed the leukemic monoclonal rearrangement as well as polyclonal rearrangements from normal lymphocytes and 12 (46%) relapsed; and there were 117 patients in whom only polyclonal rearrangements could be detected and only 29 (25%) relapsed. In patients who relapsed, remissions were shorter in those patients in whom the leukemic rearrangements had been detected in the remission marrow. Treatment in the later trial was more intensive than in the earlier trial, the results were better and the PCR detected the leukemic rearrangement in the remission marrow in significantly fewer patients. We conclude that detection by PCR of the monoclonal gene rearrangement of the leukemic clone in remission marrow indicates that numerous leukemic cells have survived induction therapy and is a good predictor of relapse. However, due to limited sensitivity of the test, failure to detect the leukemic clone by PCR is not a sufficiently good predictor of ultimate cure.

Bone Marrow↗
PubMed1992

HLA-DR1 is not a sign of poor prognosis for the development of multiple basal cell carcinomas.

BACKGROUND: HLA-DR1 is associated with the development of multiple basal cell carcinomas (BCC). However, the association is weak. OBJECTIVE: The purpose of our study was to determine whether HLA-DR1 is a marker for susceptibility to the development of many BCCs during a lifetime. METHODS: Persons with multiple BCCs were placed into two groups: those with less than 10 and those with 20 or more. In addition, the HLA-DR1 frequencies were analyzed. RESULTS: HLA-DR1 was associated with multiple BCCs in the group with less than 10 BCCs but not with the other group. These patients were significantly younger on average than those with 20 or more BCCs. CONCLUSION: HLA-DR1 is associated with the development of multiple BCCs at an early age but it is not associated with development of large numbers of BCCs. The amount of UV light a person receives appears to be more important.

Age Factors↗
PubMed1992

Multiple basal cell carcinoma in tropical Australia.

No association between HLA DR1 and the development of multiple basal cell carcinomas (BCC) was found among patients who had lived at least two-thirds of their lives in the tropics. The percentage of patients with multiple BCCs increased with age; this was different from what has been found in people living in the temperate zone of Australia.

Adult↗
PubMed1992

Skin cancers and HLA frequencies in renal transplant recipients.

An association between HLA DR7 and the development of multiple non-melanoma skin cancer was detected in immunosuppressed patients in southern Australia. The relative risk was 2.6 which was lower than for immunocompetent patients with the same skin cancers. HLA frequencies of renal transplant recipients with multiple skin cancers were determined. The types HLA B27 and HLA Dr7 were found in significantly higher frequency, and there was no absence of HLA A11.

Adult↗
PubMed1991

Multiple basal cell carcinomas and HLA frequencies in southern Australia.

An association between HLA-DR1 and the development of multiple basal cell carcinomas was detected in southern Australia. A reduction in HLA-DR4 was found in patients with basal cell carcinoma compared with a local control group. The relative risk for HLA-DR1 was 2.1, which was lower than that for persons in farther countries from the equator.

Adult↗
PubMed1991

Age and multiple basal cell carcinomas in Australia.

A survey of patients with skin cancer in southern Australia detected that the development of multiple BCCs is common. The incidence of multiple BCCs peaks during the sixth decade and reaches a plateau. Human leukocyte antigen (HLA) DR1 was associated with the development of multiple BCCs in people under the age of 55, but not in older people.

Adult↗
PubMed1985

Motor impersistence: a right-hemisphere syndrome.

We studied motor impersistence with a standardized clinical test of sustained actions, both in patients with acute focal stroke lesions, who were matched for age and size of lesion, and normal controls. Patients with right-sided lesions had significantly more impersistence than did those with left-sided lesions. The most discriminating tests were eye-closure, mouth-opening, tongue-protrusion, and gaze to the left. Right central and frontal lesions seemed to be more responsible for motor impersistence than were posterior or left-sided lesions. Although motor impersistence is sometimes seen with diffuse cerebral disease, it is also a sign of right-hemisphere lesions; the phenomenon is probably related to mechanisms of directed attention that are necessary to sustain motor activity.

Adult↗
PubMedDate not supplied

Young Investigator Award presentation at the 13th Annual Meeting of the ESMRMB, September 1996, Prague. A proton-electron double-resonance imaging apparatus with simultaneous multiple electron paramagnetic resonance irradiation at 10 mT.

The detection of free radicals in vivo is very important for the study of many physiologic and pathologic conditions. Free radicals have been implicated in a number of diseases such as ischemia, inflammation, kidney damage, and cancer. Proton-electron double-resonance imaging (PEDRI) allows the indirect detection of free radicals via the Overhauser effect. Nitroxide free radicals used for in vivo PEDRI studies present spectra with two or three lines, but most PEDRI experiments performed to date have used only single-line electron paramagnetic resonance (EPR) irradiation. There is theoretical evidence that simultaneous irradiation of multiple EPR transitions could increase the maximum achievable PEDRI enhancement. From the experimental point of view, this requires the combined use of a suitable multiple-frequency EPR source and a multiple-tuned EPR resonator. A novel radiofrequency (RF) triple-tuned loop-gap resonator for use in PEDRI has recently been developed, and dynamic nuclear polarization (DNP) data were reported. In the present study we describe a new PEDRI apparatus, equipped with a triple-tuned resonator, that is suitable for simultaneous double- or triple-EPR irradiation of nitroxide free radicals. In particular, the details of the EPR hardware used to generate the two or three EPR frequencies are given, and PEDRI images obtained with simultaneous multiple EPR irradiation are shown. Moreover, DNP experimental results showing the increase of the enhancement as a function of the EPR power for single and simultaneous double EPR irradiation are presented. The main goal of this apparatus is to improve the sensitivity and/or to reduce EPR irradiation power in a PEDRI experiment. This is likely to be particularly important in future biologic applications of PEDRI where the applied power must be optimized to reduce sample heating.

Awards and Prizes↗