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Biomedical subjects

C Morgan

Publications and source records attributed to C Morgan.

At least 55 records · Page 3Linked to original sources

Laminin inhibits amyloid-beta-peptide fibrillation.

Laminin, an important extracellular matrix component is induced by brain injury and colocalizes with amyloid-beta-peptide (A beta) deposits in Alzheimer brains. We report here that laminin inhibits amyloid fibril formation as determined by thioflavin T fluorescence spectroscopy and electron microscopic examination. The inhibition of amyloid formation by laminin was concentration dependent and was observed at a laminin concentration of 300 nM, corresponding to a laminin/A beta protein molar ratio of 1:800. The potential effect of laminin, may prove important to inhibit A beta fibrillogenesis in vivo, specifically at the level of cerebral blood vessels.

Amyloid beta-Peptides↗

The significance of microbial cultures of the hematopoietic support for patients receiving high-dose chemotherapy.

The use of hematopoietic support for patients receiving high-dose chemotherapy has increased over the past 10 years. Various quality controls are performed on the hematopoietic cells, including microbiologic cultures. There is considerable expense associated with the serial cultures performed at different times during the collection, processing, and use of the cells. We reviewed all the microbiologic cultures performed on bone marrow harvests and leukaphereses over a 17 month period. Of the 227 bone marrow harvests, 16 cultures were positive, but only 3 (1.3%) were repeat positives with the same organism after processing or at the time of reinfusion. Of the 560 leukaphereses, 4 (0.7%) were cultured positive at the time of collection and reinfusion. Two patients were bacteremic with gram-negative bacilli at the time of leukaphereses despite being asymptomatic, and these were the only two products that had to be collected again. No patient suffered an adverse clinical result after receiving culture-positive cells. Bone marrow and peripheral blood progenitor cells can be safely collected, and a culture after processing is adequate to ensure the safety of the product.

Blood↗

Multilocular renal cyst: a diagnostic pitfall on fine-needle aspiration cytology: case report.

Benign renal lesions, apart from simple cysts, are rarely sampled by fine-needle aspiration biopsy (FNAB) and are potential diagnostic pitfalls. A complex renal mass in a 33-yr-old pregnant woman, presenting in the second trimester with haematuria, was aspirated twice, a week apart, under ultrasound guidance. The second FNAB yielded predominantly mesenchymal elements thought to represent an angiomyolipoma, but the mass was identified as a multilocular renal cyst (MLRC) on the nephrectomy specimen. Differential diagnoses of angiomyolipoma, MLRC, and renal cell carcinoma (RCC) are compared and discussed in relation to patient management.

Adult↗

Bone morphogenetic proteins inhibit adipocyte differentiation by bone marrow stromal cells.

The bone morphogenetic proteins were originally identified based on their ability to induce ectopic bone formation in vivo and have since been identified as members of the transforming growth factor-beta gene superfamily. It has been well established that the bone morphogenetic cytokines enhance osteogenic activity in bone marrow stromal cells in vitro. Recent reports have described how bone morphogenetic proteins inhibited myogenic differentiation of bone marrow stromal cells in vitro. In vivo, bone marrow stromal cells differentiate along the related adipogenic pathway with advancing age. The current work reports the inhibitory effects of the bone morphorphogenetic proteins on adipogenesis in a multipotent murine bone marrow stromal cell line, BMS2. When exposed to bone morphogenetic protein-2, the pre-adipocyte BMS2 cells exhibited the expected induction of the osteogenic-related enzyme, alkaline phosphatase. Following induction of the BMS2 cells with adipogenic agonists, adipocyte differentiation was assessed by morphologic, enzymatic, and mRNA markers. Flow cytometric analysis combined with staining by the lipophilic fluorescent dye, Nile red, was used to quantitate the extent of lipid accumulation within the BMS2 cells. By this morphologic criteria, the bone morphogenetic proteins inhibited adipogenesis at concentrations of 50 to 500 ng/ml. This correlated with decreased levels of adipocyte specific enzymes and mRNAs. The BMS2 pre-adipocytes constitutively expressed mRNA encoding bone morphogenetic protein-4 and this was inhibited by adipogenic agonists. Together, these findings demonstrate that bone morphogenetic proteins act as adipogenic antagonists. This supports the hypothesis that adipogenesis and osteogenesis in the bone marrow microenvironment are reciprocally regulated.

Adipose Tissue↗

A cancer-prevention intervention for disadvantaged women: design and implementation.

A cancer-prevention mini-course was designed to increase knowledge about breast and cervical cancers as well as to improve attitudes and behaviors regarding preventive health care among minority and medically underserved women. The culturally-sensitive two-hour psycho-educational intervention was developed as an interactive curriculum in English- and Spanish-language versions for home health care attendants. After development and piloting, the course was offered as part of the weekly 40-hour training program for home attendants in Bronx, New York. After six months it was offered as in-service training for home attendants employed by a licensed home attendant-training agency. The home attendants who participated in the mini-course were primarily Hispanic (62%) and black (31%). Results of evaluation indicate that the mini-course has been remarkably successful in achieving its goals. Primary measures of its success include: 1) integration of the mini-course into the settings in which it is being offered; 2) student participation, absorption of material, and enthusiasm for the course. The mini-course has been successfully incorporated into the training agencies, with strong staff commitment to the program. Participants evince high levels of enthusiasm for the class, reporting that they have learned new information and have especially enjoyed the interactive nature of the class. Though the development of this cancer-prevention mini-course (and its materials) as well as integrating it into appropriate settings required a substantial investment of time and resources, now that it is developed, the intervention proves to be efficient and effective, and is meeting a large need.

Adult↗

Do patients need to remain in bed following embryo transfer? The Birmingham experience of 103 in-vitro fertilization cycles with no bed rest following embryo transfer.

Since the early days of human in-vitro fertilization and embryo transfer, rest in bed for hours immediately following the transfer has been advocated and widely practised. However, there is no scientific validation for this practice which is both time-consuming for the patient and increases space occupancy in the hospital or clinic. We report here on a study of 103 in-vitro fertilization cycles with no bed rest in hospital following the embryo transfer. The mean number of embryos transferred was 2.7 (range 1-3) and the clinical pregnancy rate per embryo transfer procedure was 40%. These results suggest that bed rest is not necessary following embryo transfer.

Adult↗

Ovarian response in consecutive cycles of ovarian stimulation in normally ovulating women.

Ovarian stimulation combined with intra-uterine insemination (IUI) is an effective treatment of non-tubal infertility but most women undergo several cycles of treatment to achieve a pregnancy. This prospective study was designed to assess the consistency (or variation) of ovarian responses and the effect of various ovarian stimulation protocols on this consistency in consecutive cycles of ovarian stimulation and IUI in women with non-ovulatory infertility. A total of 86 regularly menstruating ovulating patients each completed three to six cycles of ovarian stimulation and IUI (n = 347 cycles). Ovarian stimulation was achieved by sequential clomiphene citrate/human menopausal gonadotrophin (HMG), HMG-only or combined gonadotrophin-releasing hormone analogue--HMG protocols in 33, 29 and 24 patients respectively, and each patient used the same protocol consistently throughout the study. Standard methods were used to monitor ovarian response and to perform IUI. Using each patient as her own control, repeated measurements analysis of variance revealed consistency of ovarian response in consecutive ovarian stimulation cycles, as shown by the number and mean diameter of maturing pre-ovulatory follicles, peak plasma oestradiol, duration of stimulation and mean HMG requirements. This consistency existed using any of the ovarian stimulation protocols. We conclude that regularly menstruating and ovulating women are likely to have similar ovarian responses in consecutive cycles of ovarian stimulation and IUI if the same ovarian stimulation protocol is used consistently.(ABSTRACT TRUNCATED AT 250 WORDS)

Cervix Mucus↗

Lipopolysaccharide regulation of lipoprotein lipase expression in murine macrophages.

The enzyme lipoprotein lipase is expressed in a number of cell types and plays a central role in lipid metabolism. Multiple factors regulate its expression in a tissue-specific manner. In murine macrophages, lipopolysaccharide inhibits lipoprotein lipase enzyme activity. The current work examines this process in the established J774 macrophage line and primary peritoneal macrophages from endotoxin-sensitive (C3HeB/Fej) and endotoxin-resistant (C3H/Hej) murine strains. Lipopolysaccharide inhibition of macrophage lipoprotein lipase occurred at the enzyme and mRNA levels in a time- and concentration-dependent manner. Cells from endotoxin-resistant animals maintained their expression of lipoprotein lipase following treatment with lipopolysaccharide. Results of gel retention assays showed that lipopolysaccharide treatment of the J774 macrophages altered the level of nuclear proteins recognizing and binding the lipoprotein lipase promoter DNA. Nuclear extracts from resting J774 cells contained proteins which bound specifically to the octamer motif and to the CAAT box within the lipoprotein lipase promoter. Exposure of the J774 cells to lipopolysaccharide for 16 h increased the level of protein-octamer DNA complexes. Similar responses were obtained in endotoxin-sensitive, but not endotoxin-resistant, primary macrophages following in vitro treatment with lipopolysaccharide. This finding suggests that transcriptional events may contribute to the lipopolysaccharide regulation of macrophage lipoprotein lipase expression.

Animals↗

In vitro and in vivo analysis of murine lipoprotein lipase gene promoter: tissue-specific expression.

Lipoprotein lipase, an enzyme of central importance to lipid metabolism, is most abundant in adipose tissues, cardiac and skeletal muscle, and portions of the brain. The current work examined the murine lipoprotein lipase promoter using transient transfection, gel-retention analyses, and transgenic mice. Maximum expression of the luciferase reporter gene in transfected cells was observed with -101 bp of the promoter. Nuclear extracts from tissues expressing lipoprotein lipase contained DNA binding proteins that recognize the CCAAT box (-64 bp) and an octamer motif (-46 bp); this combination of factors was absent in nonexpressing tissues. Transgenic mice from three of five founders prepared with -1,824-bp promoter constructs expressed the luciferase reporter gene at highest levels in brown adipose tissue and brain. These findings suggest that the -1,824-bp promoter region contains sequence elements responsible for the tissue-specific transcription of lipoprotein lipase in vivo.

Animals↗

Saturable binding sites for the coenzyme A ester of nafenopin, a peroxisome proliferator, in rat liver cytosol.

1. At least three different molecular weight binding sites exist in rat liver cytosol for nafenopin-CoA, the coenzyme A ester and metabolic product of the carcinogenic peroxisome proliferator nafenopin. No binding sites for the free drug were observed. 2. Polypeptides of 35-40 kDa molecular weight range where no acyl-CoA binding proteins have been previously described bind the highest proportion of nafenopin-CoA (60-70%). Binding is displaceable by the CoA esters of other peroxisome proliferators (ciprofibrate and tibric acid) and also by oleoyl-CoA but by palmitoyl-CoA. Direct binding studies show that 35-40-kDa polypeptides bind oleoyl-CoA but not oleic or palmitic acid, or palmitoyl-CoA. 3. Polypeptides of 10-14 and 65-70 kDa also bind nafenopin-CoA. However, in contrast with 35-40-kDa polypeptides they also bind oleic and palmitic acid as well as their correspondent acyl-CoA thioesters.

Acetyl Coenzyme A↗

Psychosocial variables associated with teenage pregnancy.

This study investigated whether psychosocial factors differentiate sexually active teenagers who become pregnant from those who do not. Data were collected from 64 unmarried adolescents who attended a suburban health clinic for a pregnancy test or for contraceptive care. Thirty-nine percent of the sample had been or were now pregnant, and 61% had never been pregnant. Each teenager completed a questionnaire and three self-report measures (Life Events Checklist, Self-Worth, Health Locus of Control) prior to her medical visit. Information about family, medical, and psychosocial history was obtained from chart review. When girls who had positive pregnancy tests, and sexually active girls who had never been pregnant were compared, no significant differences emerged on socioeconomic status, race, religion, age or psychological variables. However, when adolescents with a previous or current history of pregnancy (N = 25) were compared with girls who had never been pregnant (N = 39), using the Mann Whitney test, two significant differences were found: adolescents with a history of pregnancy had first intercourse at the mean age of 15 rather than 16 (p < .02) and scored higher than never-pregnant teenagers on the "Powerful Other" Health Locus of Control subscale, a measure of strong belief in external control by others (p < .01). No significant differences were detected between the groups for self-worth or life events perceived as stressful during the past year. These data indicate that in a middle-class suburban population of sexually active teenagers, earlier age at first intercourse and the influence of powerful others are important variables associated with pregnancy.

Adolescent↗

Tropical spastic paraparesis occurring in HTLV-1 associated infective dermatitis. Report of two cases.

An association between HTLV-1 infection and infective dermatitis (ID) a relapsing eczematous condition of Jamaican children, was reported in 1990. These patients are at risk of developing other known HTLV-1 related diseases. We have observed the development of HTLV-1 associated myelopathy/tropical spastic paraparesis in two patients, ages 14 and 35 years, who were diagnosed with ID at ages 2 and 10 years, respectively. Infective dermatitis of children serves as an early marker of HTLV-I infection and may predict later development of either the malignant outcome, adult T-cell leukaemia/lymphoma or the neurologic manifestation HAM/TSP among adult carriers of HTLV-1 infection.

Adolescent↗

Beliefs, knowledge, and behavior about cancer among urban Hispanic women.

As part of a cancer prevention program aimed at minority and disadvantaged urban women, cancer beliefs, knowledge, and behaviors were assessed among home-health attendants in the Bronx, N.Y. Information, was gathered from 876 Hispanic women who comprised 62% of the female home-attendant study population from whom data were collected (n = 1413). Of these women, 82% (n = 718) were Spanish speaking and 18% (n = 158) were English speaking as defined by their choice to complete the survey questionnaire in Spanish or English. As a whole, the population reported high levels of obtaining screening tests and engaging in preventive behaviors. However, nearly 60% did not know what cervical cancer was. The most important predictor of inadequate cancer screening was lack of knowledge. Large numbers of women subscribed to cancer misconceptions, such as the belief that bumps or bruises cause cancer. Fifty-eight percent believed that surgery causes cancer to spread, a belief that may prevent a woman with breast cancer from undergoing early intervention procedures, such as lumpectomy. This survey indicated that Hispanic women in our population engaged in relatively high levels of cancer preventive behaviors, even though their knowledge base was limited. Many of them hold misperceptions about cancer that can have an impact on preventive behaviors. We conclude that cancer prevention programs targeting the Hispanic populations should emphasize the provision of factual information about cancer and cancer-screening behaviors in the context of an exploration of inaccurate beliefs about cancer that may inhibit preventive health behaviors.

Adult↗

Importance of ST-segment depression as a determinant of ventricular premature complex frequency after thrombolysis for acute myocardial infarction. Tissue Plasminogen Activator: Toronto (TPAT) Study Group.

Ventricular premature complexes (VPCs) after acute myocardial infarction (AMI) remain important determinants of survival in the post-thrombolytic era. The role of thrombolysis, left ventricular function, and Holter ST-segment depression in modulating VPC frequency is unclear. In a placebo-controlled, randomized study of tissue-type plasminogen activator (t-PA) in 103 patients with AMI (Tissue Plasminogen Activator: Toronto study), VPC frequency and ST depression on Holter monitoring (day 7), ejection fraction by radionuclide scan (day 9), and infarct artery patency and cross-sectional area on day 1 (n = 42) were assessed. After administering t-PA, VPC frequency was 10 +/- 58/hour (mean +/- SD), similar to that after placebo (23.5 +/- 91.7, p = NS). However, patients with ST depression had greater VPC frequency (56 +/- 140/hour) than those without it (1.3 +/- 2.6/hour, p = 0.05). Ejection fraction was negatively correlated with VPC frequency (r = -0.33, p < 0.001). By multivariate analysis, ejection fraction (F = 7.0, p < 0.01) and ST depression (F = 5.8, p < 0.02) were the only independent predictors of VPC frequency. In this placebo-controlled study, VPC frequency after AMI was not related to thrombolytic administration but was associated with ST depression and ejection fraction. This suggests that the underlying extent of both infarcted and ischemic myocardium is important in modulating ventricular arrhythmias after AMI.

Aged↗

Cloning and expression of the A2a adenosine receptor from guinea pig brain.

A full-length complementary DNA (cDNA) clone encoding the guinea pig brain A2 adenosine receptor has been isolated by polymerase chain reaction (PCR) and low-stringency-hybridization screening of a guinea pig brain cDNA library. This cDNA contains a long open reading frame encoding a 409-amino acid-residue protein which is highly homologous to the A2 adenosine receptors previously cloned from other species. Hydrophobicity analysis of the deduced protein sequence reveals seven hydrophobic regions, characteristic of a member of the G-protein-coupled receptor superfamily. Radioligand binding assay and functional (GTPase and cAMP) assays of the receptor, transiently expressed in mammalian cells, demonstrate typical characteristics of the A2 type adenosine receptor. The messenger RNA (mRNA) of this A2 receptor is found in the brain, heart, kidney and spleen. Receptor autoradiography with [3H]CGS21680, a specific A2 agonist, and in situ hybridization with A2 cRNA probe in guinea pig brain indicate that the receptor is expressed exclusively in the caudate nucleus. The pharmacological profile and anatomical distribution of this receptor indicate that it is of the A2a subtype. This work represents the first cloning of an A2a receptor in a rodent species, offers a complete pharmacological characterization of the receptor and provides an anatomical comparison between binding profile and gene expression of the receptor.

Amino Acid Sequence↗