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Biomedical subjects

M Ross

Publications and source records attributed to M Ross.

At least 127 records · Page 7Linked to original sources
PubMed1995

Temperature measurements of shock-compressed liquid hydrogen: implications for the interior of Jupiter.

Shock temperatures of hydrogen up to 5200 kelvin were measured optically at pressures up to 83 gigapascals (830 kilobars). At highest pressures, the measured temperatures are substantially lower than predicted. These lower temperatures are caused by a continuous dissociative phase transition above 20 gigapascals. Because hydrogen is in thermal equilibrium in shock-compression experiments, the theory derived from the shock data can be applied to Jupiter. The planet's molecular envelope is cooler and has much less temperature variation than previously believed. The continuous dissociative phase transition suggests that there is no sharp boundary between Jupiter's molecular mantle and its metallic core. A possible convectively quiescent boundary layer might induce an additional layer in the molecular region, as has been predicted.

Chemical Phenomena↗
PubMed1995

Isolation and characterization of a cyclic hydroxamic acid from a pollen extract, which inhibits cancerous cell growth in vitro.

One fraction, designated FV-7, in the water soluble ingredient of the pollen extract Cernilton was found to be inhibitory to the growth of a prostate cancer cell line. Characterization of FV-7 by high-resolution mass spectrometry and nuclear magnetic resonance identified the fraction as hydroxamic acid, 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one (DIBOA). To confirm this further, we synthesized an authentic sample of DIBOA and found subsequently that the synthetic DIBOA was structurally indistinguishable from FV-7. Furthermore, in a separate experiment we compared the in vitro effects of FV-7 and DIBOA on the growth of a prostate cancer cell line and found that in both cases the effect was inhibitory and that the inhibition curves obtained for both compounds were virtually identical.

Antineoplastic Agents, Phytogenic↗
PubMed1995

Identification of a prostate inhibitory substance in a pollen extract.

Recently, much attention has focused on the treatment of BPH with the pollen extract, Cernilton. The present investigation was designed to identify the active component in this agent which might be responsible for the symptomatic relief of BPH as previously reported. Sequential purification of the active component present in the pollen extract was carried out by a combination of dialysis, gel filtration, and reverse phase chromatography. To monitor the biological activity of each of the purified fractions, a biological assay employing the human prostate cancer cell line DU145 was undertaken. While we have identified a number of constituent components in the pollen extract, only one fraction designated V-7 (FV-7) maintained a strong inhibitory effect on the growth of DU145 cells. The inhibition was time- and dose-dependent, and the concentrations of FV-7 required to reduce the cell numbers by 50% (IC50) after 2 days of exposure was 5 micrograms/ml. FV-7 was also inhibitory towards the primary culture of prostate stroma and epithelial cells, with the stroma/fibroblast showing greater sensitivity towards the HPLC-purified component. However, it should be noted that this inhibitory activity measured in the primary culture cells was only achieved at higher concentrations of FV-7. Preliminary characterization of the active ingredient identified FV-7 as DIBOA which is a cyclic hydroxamic acid. FV-7 and DIBOA induce similar inhibitory effects on the growth of DU145 cells.

Cell Division↗
PubMed1995

Evaluation of GM-CSF mouthwash for prevention of chemotherapy-induced mucositis: a randomized, double-blind, dose-ranging study.

Uncontrolled clinical trials have shown that parenteral administration of GM-CSF reduces the frequency of chemotherapy-induced mucositis. The mechanism of this effect could be related to acceleration of haematopoiesis and/or increase in functional activation of WBC. We conducted a double-blind, placebo-controlled, dose ranging study of GM-CSF (mol-gramostim) mouthwash in patients with breast cancer during the first treatment cycle of a combination chemotherapy regimen which has historically produced dose-limiting (grade > or = 3) mucositis in approximately 39% of patients. Subjects were randomized to receive either placebo mouthwash (0.1 percent albumin) or one of four concentrations of GM-CSF mouthwash (0.01, 0.1, 1.0 or 10 mcg/ml). The primary endpoint was to evaluate the relationship between dose of GM-CSF mouthwash received and probability of grade > or = 3 mucositis using a logistic model. Solutions were administered four times daily starting within 24 hours of chemotherapy initiation and continuing until the end of the cycle (day 21). Mucositis was assessed on days 1-6, 10, 15 and 21. Day 6 plasma samples were assayed for GM-CSF. Forty-five patients were evaluable for response (nine per dosing group). A 42% risk (15/36) of mucositis grade > or = 3 was evident on day 15 in patients receiving GM-CSF compared to 2 of 9 patients on the placebo arm. No evidence of dose response was found by logistic regression. Five patients had a detectable plasma concentration of GM-CSF (56-209 pg/ml). A positive correlation between GM-CSF dose and leukocyte recovery was noted (P = 0.04).

Adult↗
PubMed1995

The influence of smoking and diet on the hypoxanthine phosphoribosyltransferase (hprt) mutant frequency in circulating T lymphocytes from a normal human population.

The influence of the dietary antioxidants vitamin C, alpha- and beta-carotene, lycopene, lutein/zeaxanthin, phytofluene, beta-cryptoxanthin, retinol and alpha- and gamma-tocopherol on the hypoxanthine phosphoribosyltransferase (hprt) mutant frequency in human peripheral T lymphocytes was investigated. Twenty-five male non-smokers and 27 male smokers in the age range 50-59 years were recruited. Smokers showed a significantly higher mutant frequency compared with non-smokers (X1.5, P < 0.01). In addition, there was a significant positive relationship between hprt mutant frequency and the number of cigarettes that individuals reported smoking daily (P < 0.01). Smokers showed significantly lower levels of plasma vitamin C and the carotenoid alpha-carotene than non-smokers (P < 0.01 and P < 0.05 respectively). Both hprt mutant frequency and lymphocyte plating efficiency were weakly inversely associated with plasma vitamin C levels (P < 0.07 and P < 0.06 respectively) suggesting that vitamin C may be protective against mutation at the hprt locus. This relationship was markedly stronger in smokers (P < 0.01).

Adult↗
PubMed1995

A case for synchronous reduction of testicular androgen, adrenal androgen and prolactin for the treatment of advanced carcinoma of the prostate.

The present study was undertaken mainly to investigate whether prolactin manipulation combined with maximal androgen blockage improves the effectiveness of treatment in advanced prostatic cancer. The efficacy of oral hydrocortisone as an alternative to commercial anti-androgens in reducing the adrenal androgens, and of bromocriptine in reducing the prolactin level were also examined. A consecutive series of 30 patients with untreated and advanced prostatic cancer were entered into a three-arm prospective randomised trial. 10 patients received subcapsular orchiectomy alone (arm 1), another 10 had subcapsular orchiectomy plus flutamide (arm 2), and the remaining 10 had subcapsular orchiectomy plus oral hydrocortisone and bromocriptine (arm 3). Clinical and biochemical parameters, including trans-rectal ultrasound-determined prostatic volumes, hormonal profiles and radionuclide bone scan were evaluated at regular intervals. At 12 months, serum testosterone was reduced by more than 90% in all arms, however, maximum suppression of androstenedione, prolactin, and reduction of prostatic volumes were only observed in arm 3; this was reflected by the significant improvement in clinical response in arm 3 compared with other arms. This study suggests that a combined maximal suppression of androgens and prolactin offers a significant improvement in response over conventional treatments without prolactin suppression in the treatment of advanced prostatic cancer. Importantly, a better clinical outcome in arm 3 was still apparent at the end of 36 months.

Androgen Antagonists↗
PubMed1995

Violence content in nursing curricula: strategic issues and implementation.

Many nurse educators today are sensitized to the importance of including content on violence and victim/survivor care in various nursing education programmes. While a survey of Ontario's schools of nursing in Canada revealed a considerable number of hours devoted to this topic, the approach is largely incidental, depending heavily on individual faculty interests. National and international initiatives to stem the tide of violence against women and children, plus the strategic role of nurses in primary care, call for curricula in which this content is addressed systematically. To achieve this goal and avoid pitfalls such as an 'add-on' approach to curriculum revision, nurse educators' needs in Ontario were addressed in a series of workshops involving collaboration between faculty, clinical preceptors and community-based experts in victim/survivor care.

Adult↗
PubMed1995

Interleukin-1 production in tumor cells of human melanoma surgical specimens.

To determine whether IL-1 alpha and/or IL-1 beta protein is expressed by human melanoma tumor in vivo, we first analyzed nine human melanoma cell lines and optimized the in situ detection of these proteins. Three of the melanoma cell lines stained positively for both IL-1 alpha and IL-1 beta using immunohistochemistry (IHC). THe specificity of IHC was confirmed by the ability of purified recombinant IL-1 alpha and IL-1 beta protein to abolish the staining after being adsorbed by their respective antibodies before use in IHC. The three positively staining cell lines were also the only lines to demonstrate IL-1 production by western blot analysis as well as IL-1 secretion by ELISA. Next we examined 29 surgically obtained melanoma tumor specimens (6 primary and 23 metastases) that had been formalin fixed and paraffin embedded. Using the same anti-IL-1 antibodies, 5 of 23 metastatic tumors stained positively. None of the 6 primary lesions stained for either IL-1 alpha or IL-1 beta. Comparison of staining pattern performed on serially sectioned tissue using preimmune serum and antibodies against S-100 protein, melanoma-associated antigen (HMB-45), and CD68 (kappa P1), which recognizes monocyte-macrophage cell lineage, demonstrates for the first time that IL-1 protein is produced by human melanoma tumor cells in vivo. These findings provide the basis for examination of what may be a previously unrecognized biologically distinct subset of patients.

Analysis of Variance↗
PubMed1995

A gene (SRPX) encoding a sushi-repeat-containing protein is deleted in patients with X-linked retinitis pigmentosa.

X-linked retinitis pigmentosa (XLRP) is characterized by retinal degeneration with night blindness and progressive reduction of the visual fields. By linkage and deletion analysis a gene locus (RP3) has been mapped to the short arm of the X chromosome between the genes CYBB and OTC. Analysis of transcript in this region has revealed a gene which is abundantly expressed in human retina and encodes a putative membrane protein with significant homologies to short consensus repeat (SCR/sushi) domains known from selections and complement proteins. The gene termed SRPX (sushi-repeat-containing protein, x chromosome) is deleted in an RP patient who also suffers from chronic granulomatous disease and McLeod syndrome. A 75 kb deletion removing exon 1 of the gene was also found in two brothers of a second XLRP family. However, no further functionally significant mutations were detected by SSCP screening of all 10 exons in 34 unrelated XLRP patients nor by full length RT-PCR sequencing in two RP3 families. The role of this highly conserved retinal gene in the pathogenesis of RP therefore remains to be determined.

Adult↗
PubMed1995

Stem cell isolation.

High-dose chemotherapy with autologous hematopoietic progenitor cell support is increasingly used to treat a variety of malignant diseases. A drawback of this technique is the potential for infusing clonogenic tumor cells with the autograft, producing relapse of the disease in the patient. The use of positive selection techniques to isolate stem cells and thus reduce or eliminate tumor cell contamination has been extensively studied over the past few years. Preliminary clinical results have demonstrated that these procedures deplete 2 to 7 logs of tumor cells and do not impair engraftment. It is too early to assess the ultimate clinical benefit of this strategy. Additional applications of CD34-selection include ex vivo expansion of and gene transfer into hematopoietic progenitor cells and T-cell depletion of allogeneic grafts to reduce the incidence of graft-versus-host disease.

Antigens, CD34↗
PubMed1995

Effects of granulocyte-macrophage colony stimulating factor produced in Chinese hamster ovary cells (regramostim), Escherichia coli (molgramostim) and yeast (sargramostim) on priming peripheral blood progenitor cells for use with autologous bone marrow after high-dose chemotherapy.

Peripheral blood progenitor cells (PBPCs) were collected without prior association with chemotherapy but after the administration of granulocyte-macrophage colony-stimulating factor (GM-CSF) produced in Chinese hamster ovary cells (CHO-GM, regramostim), Escherichia coli (E. coli-GM, molgramostim), or yeast (Yeast-GM, sargramostim) and used in conjunction with autologous bone marrow after high-dose chemotherapy in 69 patients with breast cancer or melanoma. The mean peripheral white blood cell (WBC) counts increased by 2.2 to 2.7-fold after regramostim, 4.5 to 7.3-fold after molgramostim and 4.3-fold after sargramostim. All patients underwent three leukaphereses. The mean (+/- standard error) total nucleated pheresed cells per kg x 10(8) were 4.15 +/- 0.56, 15.10 +/- 1.77 and 7.24 +/- 1.00 for patients receiving regramostim, molgramostim or sargramostim respectively. The mean (+/- standard error) granulocyte-macrophage colony-forming units per kg x 10(4) mobilized into the PB were 8.75 +/- 3.63, 71.03 +/- 17.85, and 65.11 +/- 18.74 for patients receiving regramostim, molgramostim, or sargramostim respectively. The total mean (+/- standard error) CD34+ cells per kg x 10(7) collected by three leukaphereses were 3.28 +/- 1.62, 1.34 +/- 0.51 and 2.57 +/- 1.93, for patients receiving regramostim, molgramostim or sargramostim respectively. The use of either molgramostim- or sargramostim-primed PBPCs led to complete elimination of absolute leukopenia with a WBC count under 100/mm3 in 64% and 77% of patients treated, respectively. Patients receiving molgramostim-primed PBPCs required fewer red blood cells transfusions than patients receiving regramostim-primed PBPCs (p = 0.0062). Our data indicate that PBPCs collected without prior association with chemotherapy but after either molgramostim or sargramostim with autologous bone marrow support and GM-CSF shorten the hematopoietic recovery after myeloablative chemotherapy in patients with breast cancer or melanoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Effects of granulocyte-macrophage colony stimulating factor produced in Chinese hamster ovary cells (regramostim), Escherichia coli (molgramostim) and yeast (sargramostim) on priming peripheral blood progenitor cells for use with autologous bone marrow after high-dose chemotherapy.

Peripheral blood progenitor cells (PBPCs) were collected without prior association with chemotherapy but after the administration of granulocyte-macrophage colony-stimulating factor (GM-CSF) produced in Chinese hamster ovary cells (CHO-GM, regramostim), Escherichia coli (E. coli-GM, molgramostim), or yeast (Yeast-GM, sargramostim) and used in conjunction with autologous bone marrow after high-dose chemotherapy in 69 patients with breast cancer or melanoma. The mean peripheral white blood cell (WBC) counts increased by 2.2 to 2.7-fold after regramostim, 4.5 to 7.3-fold after molgramostim and 4.3-fold after sargramostim. All patients underwent three leukaphereses. The mean (+/- standard error) total nucleated pheresed cells per kg x 10(8) were 4.15 +/- 0.56, 15.10 +/- 1.77 and 7.24 +/- 1.00 for patients receiving regramostim, molgramostim or sargramostim respectively. The mean (+/- standard error) granulocyte-macrophage colony-forming units per kg x 10(4) mobilized into the PB were 8.75 +/- 3.63, 71.03 +/- 17.85, and 65.11 +/- 18.74 for patients receiving regramostim, molgramostim, or sargramostim respectively. The total mean (+/- standard error) CD34+ cells per kg x 10(7) collected by three leukaphereses were 3.28 +/- 1.62, 1.34 +/- 0.51 and 2.57 +/- 1.93, for patients receiving regramostim, molgramostim or sargramostim respectively. The use of either molgramostim- or sargramostim-primed PBPCs led to complete elimination of absolute leukopenia with a WBC count under 100/mm3 in 64% and 77% of patients treated, respectively. Patients receiving molgramostim-primed PBPCs required fewer red blood cells transfusions than patients receiving regramostim-primed PBPCs (p = 0.0062). Our data indicate that PBPCs collected without prior association with chemotherapy but after either molgramostim or sargramostim with autologous bone marrow support and GM-CSF shorten the hematopoietic recovery after myeloablative chemotherapy in patients with breast cancer or melanoma.

Animals↗
PubMed1995

Comparison of simultaneous renal clearances of true endogenous creatinine and subcutaneously administered iothalamate in man.

125I-iothalamate and true endogenous creatinine clearances, measured over two short collections periods of 1 and 2 h, were compared simultaneously in 70 patients with a variety of renal diseases and a wide range of renal function. Reproducibility of the iothalamate clearance was 18.5% and that of the creatinine clearance 12.2%. The slope of the regression was not significantly different from 1 (95% confidence interval, CI, 0.964-1.155) for the whole group, nor in any subgroup chosen. The intercept at 12.6 ml/min (CI = 5.0-20.2) indicates that there is some creatinine secretion, but this was constant at all levels of GFR. It is concluded that although the clearance of true creatinine obtained during short collection periods consistently overestimates GFR by a constant proportion, it is a reproducible and accurate measure of GFR suitable for use in the clinical setting.

Adult↗
PubMed1995

Determinations of dangerousness in forensic patients: an archival study.

The involvement of mental health professionals in determinations of dangerousness is both common and controversial. Among the various contexts for these evaluations, the release of potentially violent forensic patients from maximum security facilities evokes justified concern from involved experts and apprehension to outrage from the immediate community. We sought to examine how conclusions are reached on dangerousness at two sequential stages: clinical recommendations and Manifest Dangerousness Hearings decisions. In an archival study of 245 patients, we found that lack of progress in the institution and physical assaultiveness were the strongest correlates with dangerousness. In contrast, experts and review boards appeared to be relatively less influenced by diagnosis, types of treatment, and sociodemographic variables.

Adult↗
PubMed1994

The impact of conventional plus high dose chemotherapy with autologous bone marrow transplantation on hematologic toxicity during subsequent local-regional radiotherapy for breast cancer.

BACKGROUND: Forty patients with Stage II-III breast cancer with 10 or more positive axillary nodes were treated with mastectomy followed by four cycles of standard dose CAF (cytoxan, Adriamycin, 5-FU), followed by high dose cytoxan, cisplatin, carmustine (HDCT) with autologous bone marrow transplant support (ABMT), and local-regional radiotherapy (LR XRT). During LR XRT, the hematologic toxicity experienced by these patients appeared more severe than that usually seen in patients not heavily pretreated with chemotherapy. Radiation therapy was interrupted in four patients (10%) because of thrombocytopenia and leukopenia. This observation prompted a comparison of the hematologic changes seen in this group with those seen in patients not treated previously with chemotherapy. METHODS: A detailed analysis of changes in hematologic parameters during LR XRT was performed in 33 evaluable patients who received CAF-HDCT/ABMT and compared with a "control" group of 17 women who did not receive prior chemotherapy. RESULTS: The mean pretreatment leukocyte, platelet, and hematocrit counts were lower in the CAF-HDCT/ABMT group than in the control group, with the differences indicating statistical significance for the latter two (P = 0.17, P < 0.001, and P = 0.001, respectively). None of the control patients required a treatment interruption because of hematologic toxicity, whereas four of the CAF-HDCT/ABMT patients did. Among the CAF-HDCT/ABMT patients, a leukocyte count nadir of less than 2.0, a platelet nadir of less than 50,000, and a hematocrit nadir of less than 25 occurred in 12%, 19%, and 9%, respectively. The corresponding rates of control patients were 6%, 0%, and 0%, respectively. Relative to their pretreatment levels, however, both groups experienced similar declines in platelet and leukocyte counts. CONCLUSION: The higher rate of hematologic toxicity observed in the patients who previously received conventional chemotherapy plus HDCT/ABMT appears to have been due primarily to lower preradiotherapy blood counts.

Adenocarcinoma↗