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S Nicholson

Publications and source records attributed to S Nicholson.

At least 37 records · Page 2Linked to original sources
PubMed1998

CSF-1 and interferon-gamma act synergistically to promote differentiation of FDC-P1 cells into macrophages.

FDC-P1 cells expressing the wildtype CSF-1 receptor, FDwtfms, differentiate into macrophages during incubation with CSF-1. This response is amplified in the presence of interferon-gamma. Cells expressing the 807F mutant receptor, 807F cells, proliferate in response to CSF-1 and do not differentiate. However, in response to CSF-1 and interferon-gamma they differentiate as well. CSF-1 causes the activation of STAT proteins in FDwtfms cells, but not in 807F cells. Cellular differentiation correlates with a sustained activation of STAT1 and STAT3 in response to interferon-gamma over at least 40 hours. However, interferon-gamma alone did not cause differentiation of cells expressing either receptor. Other defects in response to CSF-1 of the 807F cells, such as lack of PLC gamma 2 activation, were not complemented by co-incubation of the cells with CSF-1 and interferon-gamma. It appears that a combination of signaling pathways are activated by CSF-1 and interferon-gamma which caused the shift of response from proliferation to differentiation in the 807F cells and an enhanced differentiation in the FDwtfms cells.

Animals↗
PubMed1997

A phase I study of high-dose tamoxifen for the treatment of refractory malignant gliomas of childhood.

Recent studies have indicated that the proliferation of malignant gliomas is in part dependent on excessive activation of protein kinase C (PKC)-mediated pathways. Conversely, inhibiting PKC may provide a novel approach for blocking glioma growth. The antiestrogen tamoxifen, a moderately potent PKC inhibitor, has been shown in vitro to block the proliferation of malignant glioma cell lines at concentrations several-fold higher than those typically attained during the treatment of breast cancer; such serum concentrations may be achieved with doses > 40 mg/m2 b.i.d. The safety and efficacy of these high doses for producing disease control in patients with malignant gliomas has recently been noted anecdotally, although a rigorous study of this agent has been lacking. To address this issue, we examined the safety and efficacy of high-dose tamoxifen in a series of children with malignant gliomas that had progressed after conventional therapy. An initial group was treated with 60 mg/m2 p.o. b.i.d. and a second group with 100 mg/m2 b.i.d. Steady-state serum tamoxifen and metabolite levels were measured in most patients. Toxicity with the regimen was minimal; two patients treated at the higher dose required reduction to the lower dose because of asymptomatic prolongation of the QT interval on an electrocardiogram. Although none of the patients exhibited clear-cut tumor regression, 4 of 14 patients had stabilization of previously progressive disease for at least 3 months; the longest survivor lived for 17 months after beginning tamoxifen. The moderate efficacy of this agent in otherwise end-stage disease coupled with its low toxicity and the relative ease of oral administration provides a rationale for proceeding with larger studies of this agent in patients with malignant gliomas, possibly as a means for potentiating the effects of conventional chemotherapeutic agents, which to date have shown limited efficacy in the treatment of these tumors.

Administration, Oral↗
PubMed1996

Inducible nitric oxide synthase in pulmonary alveolar macrophages from patients with tuberculosis.

The high-output pathway of nitric oxide production helps protect mice from infection by several pathogens, including Mycobacterium tuberculosis. However, based on studies of cells cultured from blood, it is controversial whether human mononuclear phagocytes can express the corresponding inducible nitric oxide synthase (iNOS;NOS2). The present study examined alveolar macrophages fixed directly after bronchopulmonary lavage. An average of 65% of the macrophages from 11 of 11 patients with untreated, culture-positive pulmonary tuberculosis reacted with an antibody documented herein to be monospecific for human NOS2. In contrast, a mean of 10% of bronchoalveolar lavage cells were positive from each of five clinically normal subjects. Tuberculosis patients' macrophages displayed diaphorase activity in the same proportion that they stained for NOS2, under assay conditions wherein the diaphorase reaction was strictly dependent on NOS2 expression. Bronchoalveolar lavage specimens also contained NOS2 mRNA. Thus, macrophages in the lungs of people with clinically active Mycobacterium tuberculosis infection often express catalytically competent NOS2.

Amino Acid Sequence↗
PubMed1995

'Stupid calves'.

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Animals↗
PubMed1995

The expression of emotional distress in old English prose and verse.

The Old English elegies and Alfred's translation of De Consolatione Philosophiae were examined for the presence of abstract nouns denoting adverse mood states. Large numbers of these nouns were discovered and grouped into five categories. This counters the arguments of those who believe the Anglo-Saxons expressed negative emotions chiefly in somatic terms.

Affective Symptoms↗
PubMed1994

Comparison of radioligand assay and immunostaining for epidermal growth factor receptor in human breast cancer.

Epidermal growth factor (EGF) receptor status is a useful prognostic indicator in women with breast cancer. Lack of standardization and correlation of methodology for the detection of EGF receptor has hampered its further evaluation. EGF receptor status was ascertained by immunohistochemistry and radioligand assay in 120 breast cancers. Of 52 tumours negative for EGF receptor on radioligand assay, 47 were negative on immunohistochemistry and, of 68 tumours positive for the receptor on assay, 52 were positive on immunohistochemistry. If the more widely evaluated radioligand assay is assumed to be the 'gold standard', immunohistochemistry has a sensitivity of 81 per cent and a specificity of 91 per cent.

Biomarkers, Tumor↗
PubMed1994

Semantic and episodic relations are experimentally dissociable and stochastically independent.

Subjects who studied DOG-BEER and WINE-SWEATER were more likely to recall BEER cued by DOG if they used interactive imagery rather than separate imagery, but the two groups showed no difference in recall of BEER cued by WINE. Recall of BEER cued by WINE was enhanced if BEER and "alcoholic beverages" had been presented before the list was studied, but recall of BEER cued by DOG was unaffected. We conclude that there are two independent types of relation: An episodic relation records the joint occurrence of previously unrelated words; a semantic relation reflects events in one's prior life. The value of a semantic relation is enhanced if the target item is primed in its family; the value of an episodic cue is enhanced by processes that directly encode the occurrence of the two items as a unique event in the life of the subject.

Humans↗
PubMed1994

Surgical presentations of Ehlers-Danlos syndrome type IV. A case report.

The case of a 28 year old man with Ehlers-Danlos syndrome (EDS) type IV is presented. He had the typical facies of this disorder, thin skin with atrophic scars and bruised easily. He suffered with congenital clubbed feet, heavy blood loss and poor wound healing following a traumatic compound fracture of the right leg, recurrent spontaneous pneumothoraces for which a pleurectomy was performed, two episodes of vascular rupture following minor trauma, one managed conservatively and the other surgically, and one episode of massive spontaneous vascular rupture which was fatal. In this report we highlight the surgical nature of the presenting complications of EDS type IV and demonstrate the hazards of surgical management. We conclude that, when possible, conservative management is preferable.

Adult↗
PubMed1994

Taxotere inhibits in-vitro growth of human colonic cancer cell lines.

Taxotere a semisynthetic analogue of taxol, is prepared from a precursor extracted from needles of the tree, Taxus baccata. It is a mitotic spindle poison more potent than taxol, that increases the rate of microtubule assembly and inhibits depolymerization of microtubules. There has been little research on its effects on colorectal cancer. Five colorectal tumour cell lines were investigated using three modes: flow cytometry (to determine how Taxotere affects the cell cycle), MTT assay, (to examine the cytotoxicity of the drug), and measurement of tritiated thymidine uptake, (to see whether Taxotere affects the rate of DNA synthesis and cell turnover). A time-course experiment, using flow cytometry, showed effects beginning between 0 and 2 hours after exposure. 24-hour assays were conducted for flow cytometry, and showed large changes, arresting most cells in G2/M phases (e.g., cell line LIM 1215 exposed to 1 x 10(-6) M Taxotere showed 72% of cells in G2/M compared to 14.7% in controls). 24 and 48 hour assays were conducted for MTT and measurement of tritiated thymidine uptake. MTT showed significant inhibitory effects, with maximum inhibitions varying between 5 and 70% for different cell lines after 48 hours (P < 0.05), while uptake of tritiated thymidine was not altered. While Taxotere has dose-limited toxicity, our results suggest that many human colonic cancers will be sensitive to Taxotere.

Antineoplastic Agents, Phytogenic↗
PubMed1993

Epidermal growth factor receptor determination on tumour imprints.

Epidermal growth factor receptor (EGFR) is a sensitive prognostic indicator in women with breast cancer. A new technique for the detection of EGFR on breast cancer imprints is described and evaluated in relation to immunohistochemistry on frozen sections. The standard streptavidin-biotin method using the R1 antibody on frozen sections was modified for use on tumour imprints. In the first group (group 1 imprints) 43 tumours were assessed by frozen section and imprint staining. The group 1 imprint method had a sensitivity of 50% and a specificity of 89% compared with the frozen sections. Further modifications were made for the following 32 tumours (group 2) and this method had a much improved sensitivity of 94% while specificity was preserved. This method is simple and could be performed in any hospital histopathology department.

Bacterial Proteins↗
PubMed1993

Will screening for breast cancer reduce mortality? Evidence from the first year of screening in Avon.

In the first year of screening in Avon, 93 malignant lesions were detected of which one-half were impalpable. Of the impalpable lesions, one-half were in situ or showed areas of microinvasion only. One-fifth of the malignant lesions were invasive tumours of special histological type which are known to carry a good prognosis even when not detected by screening. One-quarter of the lesions had clinical or pathological features which would be expected to confer a poor prognosis. Only 16 invasive ductal carcinomas measuring 1 cm or less in diameter were detected--a small proportion of the total number of malignant lesions. Although these early figures suggest that the effect of screening on mortality from breast cancer may be small, continued high-quality screening and careful detailed analysis are essential to determine the effect of screening on the mortality from breast cancer and the effect on the population as a whole.

Breast Neoplasms↗
PubMed1992

Prevalence of hepatitis C antibodies in patients with clotting disorders in Victoria. Relationship with other blood borne viruses and liver disease.

OBJECTIVE: To elucidate the seroepidemiology of hepatitis C in patients with clotting disorders in comparison with other blood borne infections; to examine the effects of hepatitis C on liver function; and to assess the effectiveness of current screening and inactivation procedures used in preventing the transmission of blood borne viruses by clotting factor preparations. DESIGN: A retrospective analysis of the prevalence of antibodies to hepatitis C virus (HCV), hepatitis B virus (HBV) and human immunodeficiency virus (HIV) by means of commercially available enzyme immunoassays (for antibodies to HCV and HIV) or radioimmunoassays (for HBV antibodies and surface antigen). An analysis was made of serum transaminase levels where such information was available and this was correlated with HCV status. PATIENTS AND SETTING: Panels of sera were collected from adults and children with clotting disorders attending two Melbourne haemophilia treatment centres in 1973 (n = 33), 1980 (n = 33), 1984-1985 (n = 111) and 1987-1990 (n = 217) and tested for antibodies to HCV, HBV and HIV. RESULTS: The prevalence of antibodies to HCV in the four panels tested was 45%, 74%, 75% and 76%, and the prevalence of markers of infection with HBV was 66%, 74%, 62% and 65% respectively. No antibodies to HIV were found in sera in Panels I and II but the prevalence in Panels III and IV was 23% and 36% respectively. In subjects in whom liver function test results were available, there was a significant association between the presence of antibodies to HCV and raised transaminase levels. Since heat inactivation of clotting factors was commenced in Australia in 1984, no new cases of transmission of HIV by clotting factors has been detected, but transmission of HCV in 19 subjects and HBV in one subject could not be excluded. CONCLUSIONS: Hepatitis C infection in haemophiliacs has been a very frequent event, and the presence of antibodies to HCV is associated with an increased incidence of raised transaminase levels. Screening and heat inactivation of clotting factors has prevented further HIV transmission, but exposure to HBV and HCV has not been eliminated.

Adolescent↗
PubMed1992

The development of hepatitis C antibody shortly after acute icteric non-A non-B hepatitis.

OBJECTIVE: To determine the relationship between the development of hepatitis C antibody (anti-HCV) and the clinical symptoms in acute hepatitis C. DESIGN: Retrospective analysis of sera from patients with acute non-A non-B hepatitis. SETTING AND PATIENTS: Patients admitted to Fairfield Hospital with the diagnosis of acute non-A non-B hepatitis between 1979 and 1989. Inclusion criteria included a typical clinical illness, accompanied by an alanine aminotransferase level of more than 2.5 times the upper limit of normal (normal, less than or equal to 40 U/L) and negative serological test results for acute hepatitis A and B. MAIN OUTCOME MEASURE: Time to develop anti-HCV after the onset of symptoms in patients with acute hepatitis C. RESULTS: Seroconversion was demonstrated in 26 of the 128 patients who fulfilled the inclusion criteria. In these patients, antibody was detected between one week and 32 weeks after the onset of dark urine; more than half the patients (54%) had seroconverted by four weeks and a third (34%) developed antibodies within two weeks. Of 20 patients who had sera collected within four weeks of the onset of dark urine, 14 (70%) had developed antibody. CONCLUSION: These results suggest that in patients with community-acquired hepatitis C, seroconversion occurs significantly earlier than is observed in patients who have been infected by blood transfusion. Sera taken shortly after the onset of symptomatic hepatitis C may be useful in the diagnosis of this condition.

Acute Disease↗
PubMed1992

Studies on the immediate and delayed leucocytosis elicited by brief (30-min) strenuous exercise.

Eight healthy male volunteers exercised for two 30-min sessions starting 3 h apart on an electronically braked cycle ergometer at a work load (mean 155.9 W, SD 33.4 W) which required an oxygen consumption that was 70% of their maximal rate of oxygen uptake. Venous blood samples were taken through an indwelling cannula over a period of 6 h beginning shortly before the first bout of exercise and were analysed for routine haematological parameters and for lactate, noradrenaline, adrenaline and cortisol. Both bouts of exercise induced an immediate leucocytosis due to rises in lymphocytes and neutrophils but only the first exercise bout induced a substantial delayed neutrophilia. In at least five subjects, changes in lymphocyte and platelet numbers were correlated (Spearman's rank procedure, P less than 0.05) with simultaneous changes in the plasma concentrations of lactate, noradrenaline and adrenaline over the 6-h period studied. Increases in the plasma concentration of cortisol due to exercise correlated positively with the percentage changes in neutrophil numbers at 3 h and 6 h. These results are consistent with the suggestion that the immediate and delayed leucocytosis induced by exercise are mediated respectively by catecholamine and by cortisol.

Adult↗