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Biomedical subjects

J Quinn

Publications and source records attributed to J Quinn.

At least 73 records · Page 4Linked to original sources
PubMed1997

Octylcyanoacrylate tissue adhesive versus suture wound repair in a contaminated wound model.

BACKGROUND: Octylcyanoacrylate tissue adhesive is a topical wound closure that precludes the need for foreign bodies (sutures) to close wounds. It also has an in vitro antimicrobial effect when standard disc sensitivity tests are used. METHODS: To determine whether contaminated wounds closed with octylcyanoacrylate tissue adhesive will have a lower infection rate compared with wounds closed with 5-0 monofilament sutures, we designed a randomized, blinded, experimental animal study. Two incisions were made on 20 albino guinea pigs. The wounds were contaminated with 10(5) Staphylococcus aureus ATCC 12600 and randomly assigned to be closed with either topical octylcyanoacrylate tissue adhesive or percutaneous 5-0 polypropylene suture. Five days later the adhesive and sutures were removed, and a section of the wound was given to a histopathologist blinded to the type of wound closure. The wound was determined to be infected if inflammatory cells with intracellular cocci were seen. The rest of the wound was opened and examined for clinical evidence of infection. Quantitative bacteriologic analysis was performed. RESULTS: Five wounds in the tissue adhesive group were sterile on day 5, whereas all sutured wounds had positive cultures (25% versus 0%, p < 0.05). Fewer wounds in the tissue adhesive group were determined to be infected by histologic and clinical criteria (0% versus 55%, p < 0.001, and 20% versus 65%, p < 0.01, respectively). Agreement on the determination of infection by histologic and clinical criteria yielded a kappa coefficient of 0.46 (95% confidence interval [GI], 0.19 to 0.73). An infection criterion of 10(5) colony-forming units/gm of tissue correlated poorly with clinical and histologic infection rates (0.19 [95% CI, -0.06 to 0.44] and 0.13 [95% CI, -0.05 to 0.31], respectively). CONCLUSIONS: Contaminated wounds closed with sutures had higher infection rates compared with those reported with topical tissue adhesive. The amount of colonization may not be an accurate method to determine infection.

Animals↗
PubMed1997

Association of immunophenotype with cerebrospinal fluid involvement in childhood B-lineage acute lymphoblastic leukemia.

The records of 71 pediatric patients who had B-lineage acute lymphoblastic leukemia (ALL) were studied retrospectively to document the correlation between antigenic phenotype of leukemic blasts in bone marrow (BM) and cerebrospinal fluid (CSF) involvement. Immunofluorescence assay for terminal deoxynucleotidyl transferase (TdT-IF) was used to examine specimens of CSF for the presence (CSF+) or absence (CSF-) of leukemic blasts at diagnosis and at various times after the induction of chemotherapy. The results of immunophenotyping of the leukemic blasts in the BM of the CSF+ and CSF patient groups were then compared, and the relative risk ratio and positive predictive value were calculated for each marker. In addition, other possible prognostic factors, such as gender, race and ethnicity, age, and initial leukocyte count were compared between the two groups. Thirty-eight percent of all patients, including those who had cytologically confirmed cases of CNS leukemia, had TdT+ cells in the CSF at diagnosis or during the course of the disease. No differences were observed between the CSF+ and CSF- groups with respect to clinical and demographic factors. However, the cases of CSF+ leukemia had the almost exclusive expression of cytoplasmic immunoglobulin heavy chain (c mu) or surface CD22 (Leu-14), CD23 (B6), and/or IgM markers, which normally characterize the most developmentally mature members of the B-cell series in BM. The expression of any of these antigenic markers at diagnosis appears to identify at least 88% of cases of B-lineage ALL that have or ultimately may have TdT+ cells in CSE The results of this study therefore may have both basic and clinical implications: The former concerns the mechanisms by which these phenotypically defined forms of ALL invade and persist in the CNS; the latter concerns the utility of routine immunophenotyping of BM blasts at diagnosis to assess the biologic predisposition to CNS involvement in individual cases of ALL.

Adolescent↗
PubMed1997

Effects of prostaglandins on human hematopoietic osteoclast precursors.

The effect of prostaglandin E2 (PGE2) on osteoclast (OC) differentiation is unclear, either stimulator or inhibitor, depending on the in vitro system used. This probably reflects indirect mechanisms through intermediate cells. We have investigated the direct effect of PGE2 on human OC differentiation from cord blood monocytes (CBMs) in the absence of stromal cells. Macrophages and multinucleated cells (MNCs) resembling OCs form in cultures of CBMs stimulated by 1,25-dihydroxyvitamin D3. In the present study, CBMs were cultured for 3 weeks, as previously described, in the presence or absence of PGE2. The number of MNCs was significantly reduced in the presence of PGE2 as was the proliferation of cultured CBMs, assessed on day 7. Immunohistochemistry was performed to evaluate macrophage markers (CD11b and CD14) and OC marker (beta3-chain). PGE2 significantly increased the numbers of CD11b-positive and CD14-positive cells, whereas the number of beta3-chain-positive cells was significantly decreased. beta3-Chain, c-fos, and human calcitonin receptor (h-CTR) messenger RNA (mRNA) expressions were evaluated by reverse transcription-PCR with RNA extracted from cultured CBMs. In the presence of PGE2, expression of beta3-chain and c-fos mRNA was reduced from the first week of culture. h-CTR mRNA expression was also reduced, and only the h-CTR1 isoform was detected in the presence of PGE2. In addition, when PGE2 was added only during the last week of culture, when no CBM proliferation occurred, the number of CD11b- and beta3-positive cells was unchanged compared to that in the control culture, as were the proportion of MNCs, the fusion index, and the expression of c-fos mRNA. In conclusion, our results suggest that PGE2 has an inhibitory effect on human OC differentiation from CBMs, possibly by reducing precursor proliferation in these cultures. We also hypothesize that PGE2 may reduce OC differentiation by increasing the proportion of precursor cells that differentiate into macrophages. In addition, this may be the result of inhibition of the c-fos expression in CBMs.

Calcitriol↗
PubMed1996

Molecular genetic analysis of plastocyanin biosynthesis in Chlamydomonas reinhardtii.

Five plastocyanin-deficient mutants were identified from a population of UV-mutagenized Chlamydomonas reinhardtii cells. Genetic complementation experiments indicated that four mutants represented alleles at the PCY1 locus (pcy1-2, pcy1-3, pcy1-4, and pcy1-5). Sequence analysis confirmed that two strains, pcy1-2 and pcy1-3, carry a frameshift (-1) and a nonsense mutation, respectively, while strains pcy1-4 and pcy1-5 synthesize an extended protein as a result of read-through mutations at the stop codon. The C-terminal extension does not affect synthesis or processing of the pre-proteins, but the polypeptides are rapidly degraded after the second (lumenal) processing event. The frameshift mutation in pcy1-2 results in loss of Pcy1 mRNA, as noted previously for strain ac208 (pcy1-1), but the abundance of Pcy1 mRNA in strain pcy1-3, which carries a nonsense mutation at codon 26, is unaffected relative to wild-type cells. The decreased abundance of frameshifted Pcy1 mRNA is attributed to increased degradation rather than decreased synthesis, since the mRNAs can be stabilized by treatment of cells with cycloheximide or anisomycin. The fifth strain has a wild-type plastocyanin-encoding gene, but the strain accumulates apoplastocyanin at the expense of holoplastocyanin. We suggest that the mutation identifies a new locus (PCY2) whose function is required for normal holoplastocyanin accumulation. Like ac208 (pcy1-1), several of the new mutants were suppressed spontaneously owing to accumulation of cytochrome c6 (a functional substitute for plastocyanin). The suppressor mutation(s) displayed Mendelian inheritance and segregated independently from the PCY1 locus, which confirms that regulation of Cyc6 expression is not tightly linked to plastocyanin function.

Alleles↗
PubMed1996

DNA-binding properties of the yeast SWI/SNF complex.

The SWI/SNF complex is required for the enhancement of transcription by many transcriptional activators in yeast. Genetic and biochemical studies indicate that the complex facilitates activator function by antagonizing chromatin-mediated transcriptional repression. The absence of known DNA-binding motifs in several SWI/SNF subunits and the failure to identify SWI/SNF-dependent DNA-binding activities in crude yeast extracts have led to the belief that the complex does not bind DNA. Here we show that the SWI/SNF complex has a high affinity for DNA and that its DNA-binding properties are similar to those of proteins containing HMG-box domains. The complex interacts with the minor groove of the DNA helix, binds synthetic four-way junction DNA, and introduces positive supercoils into relaxed plasmid DNA. These properties are likely to be important in the remodelling of chromatin structure by the SWI/SNF complex

Adenosine Triphosphatases↗
PubMed1996

Human cord blood monocytes undergo terminal osteoclast differentiation in vitro in the presence of culture medium conditioned by giant cell tumor of bone.

Osteoclasts (OCs), which form by fusion of hematopoietic precursor cells, are typically present in large numbers in giant cell tumors of bone (GCTBs). These tumors may, therefore, contain cells which secrete factors that stimulate recruitment and differentiation of OC precursors. Multinucleated cells resembling OCs also form in cultures of human cord blood monocytes (CBMs) stimulated by 1.25 dihydroxyvitamin D3, but these cells lack the ability to form bone resorption pits, the defining functional characteristic of mature OCs. CBMs may thus require additional stimulation to form OCs; we therefore investigated whether GCTBs are a source of such a stimulus. CBMs were stimulated in long term (21 day) culture by medium conditioned by explants of GCTBs; media collected within 15 days of explant (early-CM) and after 15 days (late-CM) were employed. We also cocultured CBMs with primary GCTB-derived stromal cells as well as immortalized bone marrow stroma-derived cells. CBMs stimulated by early-CM formed resorption pits on cortical bone slices; however, stimulation by late-CM resulted in virtually no resorption. Both early-CM and late-CM increased CBM proliferation, but not the proportion of vitronectin receptor positive or multinucleated cells. Coculture of CBMs with stromal cells of GCTBs or bone marrow did not result in bone resorption, although these stromal cells (most expressing alkaline phosphatase but progressively losing parathyroid hormone receptor expression) expressed mRNA for cytokines involved in OC differentiation, including macrophage-CSF, granulocyte-macrophage-CSF, IL-11, IL-6, and stem cell factor. Our results indicate that CBMs are capable of terminal OC differentiation in vitro, a process requiring 1,25 dihydroxyvitamin D3 as well as diffusible factor(s) which can be derived from GCTB. Stromal cells of GCTB may produce such factors in vivo, but do not support OC differentiation in vitro, possibly through phenotypic instability in culture.

Acid Phosphatase↗
PubMed1996

Disposition and metabolism of topically administered alpha-tocopherol acetate: a common ingredient of commercially available sunscreens and cosmetics.

Skin cancers are a serious health problem in the United States. One common method of skin cancer primary prevention is use of sunscreens. Research has been conducted to ascertain the role of active ingredients of sunscreen products in photoprotection and possible carcinogenesis. In contrast, little is known about the "other ingredients", listed or unlisted, on sunscreen product labels. One such ingredient is vitamin E. usually in the form of alpha-tocopherol acetate. Results of recent studies of skin carcinogenesis in an ultraviolet (UV) B mouse carcinogenesis model suggest that topically applied alpha-tocopherol acetate does not prevent and, under some conditions, enhances skin cancer development and growth, whereas the free unesterified from of alpha-tocopherol significantly reduces experimental UVB carcinogenesis. We have performed a Phase II cancer prevention study to evaluate whether topically applied alpha-tocopherol acetate is absorbed in human skin and metabolizes to the free or other forms. In this double-blind study, 19 men and women > 30 years of age who had at least three actinic keratoses on their forearms were randomly assigned to apply alpha-tocopherol acetate (125 mg/g) or difluoromethylornithine cream to their arms twice daily for three months. Blood samples and photographs and punch biopsies of actinic keratoses were obtained before and at the end of the study (Month 4). Plasma and skin concentrations of free alpha-tocopherol, alpha-tocopherol acetate, and gamma-tocopherol were analyzed by high-performance liquid chromatography at Month 4. The results of this report focus only on data obtained from the 11 participants randomized to the alpha-tocopherol acetate arm of the study. Topically applied alpha-tocopherol acetate was substantially absorbed in skin, with no evidence of conversion within skin to its unesterified form (i.e., free alpha-tocopherol). There was no evidence of systemic availability or biotransformation of topically applied alpha-tocopherol acetate. In summary, we have determined that alpha-tocopherol acetate is not metabolized to the free form of alpha-tocopherol in plasma or skin.

Administration, Topical↗
PubMed1996

Arthroplasty implant biomaterial particle associated macrophages differentiate into lacunar bone resorbing cells.

OBJECTIVE: To study the pathogenesis of aseptic loosening: in particular, to determine whether macrophages responding to particles of biomaterials commonly used in arthroplasty surgery for arthritis are capable of differentiating into osteoclastic bone resorbing cells, and the cellular and hormonal conditions required for this to occur. METHODS: Biomaterial particles (polymethylmethacrylate, high density polyethylene, titanium, chromium-cobalt, stainless steel) were implanted subcutaneously into mice. Macrophages were isolated from the foreign body granulomas that resulted, cultured on bone slices and coverslips, and assessed for both cytochemical and functional evidence of osteoclast differentiation. RESULTS: Tartrate resistant acid phosphatase (TRAP) negative macrophages isolated from granulomas containing particles of all types of biomaterial composition were capable of differentiating into TRAP positive cells capable of extensive lacunar bone resorption (assessed by scanning electron microscopy). The presence of both UMR106 rat osteoblast-like cells and 1,25-dihydroxy vitamin D3 was necessary for this to occur. CONCLUSION: All implant materials produce wear particles that are the focus of a heavy foreign body macrophage response in the fibrous membrane between a loose implant component and the host bone undergoing resorption. These findings underline the importance of biomaterial wear particle generation and the macrophage response to different types of biomaterial wear particles in the pathogenesis of aseptic loosening.

Animals↗
PubMed1996

Janet Quinn, RN, PhD. Therapeutic touch and a healing way. Interview by Bonnie Horrigan.

Janet Quinn, RN, PhD, is an associate professor and senior scholar at the Center for Human Caring at the School of Nursing, University of Colorado Health Sciences Center, in Denver, Colo. In addition to teaching she conducts research, lectures, writes, and maintains a private practice in Boulder, Colo. She received her PhD in nursing research and theory development from New York University in 1982. Quinn is a member of Sigma Theta Tau, and is active in a diverse group of professional organizations including the American Nurses Association, American Holistic Nurses Association, Association for Holotropic Breathwork International, Association for Transpersonal Psychology, International Society for the Study of Subtle Energy and Energy Medicine, Hakomi Therapy Association, and the Institute of Noetic Sciences. During her career she has received many awards including the Healers Award from the Nurse Healers and Professional Associates (1995); the Edgar S Wilson, MD, Fellowship Award from the International Society for the Study of Subtle Energies and Energy Medicine (1994); and the Holistic Nurse of the Year award from the American Holistic Nurses Association. Alternative Therapies interviewed Dr Quinn at her office in Boulder, Colo.

Complementary Therapies↗
PubMed1996

The cardiopulmonary, eicosanoid, and tissue microanatomic effects of fluconazole during graded bacteremia.

Imidazole compounds have been shown to be beneficial in systemic sepsis and inflammation. The purpose of this study was to delineate the effects of fluconazole on systemic hemodynamics and on microanatomy of the heart, lung, liver, and kidney parenchyma of swine during graded bacteremia. Eighteen adult swine were studied in three groups: 1), anesthesia control; 2), septic control (Aeromonas hydrophila, 10(9)/mL, infused i.v. for 4 h); 3) fluconazole (fluconazole, 30 mg/kg i.v., followed by A. hydrophila infusion). After 4 h of graded bacteremia, autopsy was performed. Compared with the septic control group, cardiac index, oxygen delivery, and oxygen consumption were reduced significantly after fluconazole pretreatment, and mixed venous hemoglobin oxygen saturation (SVO2) and oxygen extraction were increased. Plasma thromboxane A2 and leukotriene levels were not affected by fluconazole. Computerized digital image analysis of the liver, heart, and kidney specimens revealed no statistically significant differences between the septic control group and fluconazole-pretreated animals. In the lung specimens, preinfusion of fluconazole decreased alveolar wall thickness in septic swine (anesthesia control group: 8.15 x 10(-3) +/- 1.3 x 10(-3)mm versus septic control group: 9.9 x 10(-3) +/- 1.3 x 10(-4) versus fluconazole group: 6.8 x 10(-3) +/- 1.6 x 10(-3); p < or = .05). Fluconazole pretreatment before graded bacteremia has no beneficial effect on cardiopulmonary performance or septic tissue edema of the heart, kidney, or liver. Tissue oxygen metabolism might be down-regulated by fluconazole. However, preinfusion of fluconazole appears to normalize the sepsis-induced increase in pulmonary alveolar wall thickness. The net significance of these changes on clinical outcome is not clear from these data.

Anesthesia↗
PubMed1996

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Case Management↗