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Biomedical subjects

J Goodman

Publications and source records attributed to J Goodman.

At least 19 recordsLinked to original sources

Homing markers for atherosclerosis: applications for drug delivery, gene delivery and vascular imaging.

Endothelial dysfunction plays a major role in the pathogenesis of atherosclerosis. Pro-inflammatory cytokines such as interleukin-1 beta and tumour necrosis factor alpha activate endothelial cells changing their resting phenotype to become pro-adhesive, pro-thrombotic and pro-atherogenic. Phage display in vivo biopanning has been used to identify peptide sequences that home to diseased regions of the vessel wall in low density lipoprotein receptor (LDLr) knockout mice. In LDLr knockout mice, peptide sequence determinants exhibiting organ specificity have been isolated. These sequences have applications for gene delivery, drug delivery and for improving contrast agents for vascular imaging.

Animals↗

Practice patterns in the diagnosis and treatment of erectile dysfunction among family practice physicians.

OBJECTIVES: To examine the philosophies and practices of the family practitioner (FP) regarding the diagnosis and treatment of erectile dysfunction (ED). METHODS: A prospective study by questionnaire of a group of FPs was performed. The Spearman correlation coefficient and proportional odds regression analysis were used to measure the relationship between the continuous variable and ordinal-scale variables. The Goodman-Kruskal gamma test was used to measure the strength of the association between the ordinal-scale variables. RESULTS: Eighty-five FPs completed the questionnaire. All respondents had at least occasional discussions with their patients about ED. History taking, physical examination, and laboratory data were the most common tools used for diagnosis. Eighty-two percent of the FPs reported being either comfortable or somewhat comfortable in making a diagnosis of ED; 93% believed that only selected patients required more extensive diagnostic workups for ED. Sildenafil was the most commonly used agent. All physicians referred patients with ED to urologists at least occasionally. Most referred only after unsuccessful trials with sildenafil. The relationship between the degree of managed care penetration and the percentage of patients with ED referred for evaluation to a urologist was not statistically significant (P = 0.402). The relationship between the number of years in practice and the percentage of patients referred to a urologist for treatment or evaluation was found to be a negative, but statistically significant, relationship (P = 0.003). CONCLUSIONS: FPs are now diagnosing and treating ED on a routine basis. Referrals to urologists are likely to be made when they are no longer comfortable treating the problem.

Adult↗

Mycobacterium avium invades the intestinal mucosa primarily by interacting with enterocytes.

Previous studies have demonstrated that Mycobacterium avium can invade intestinal epithelial cells both in vitro and in vivo. When given to mice orally, M. avium preferentially interacts with the intestinal mucosa at the terminal ileum. We evaluated the mechanism(s) of M. avium binding and invasion of the intestinal mucosa using three different systems: (i) electron microscopy following administration of M. avium into an intestinal loop in mice, (ii) quantitative comparison of the bacterial load in Peyer's patch areas of the terminal ileum versus areas that do not contain Peyer's patches, and (iii) investigation of the ability of M. avium to cause disseminated infection following oral administration using B-cell-deficient mice, lacking Peyer's patches, in comparison with C57BL/6 black mice. By all approaches, M. avium was found to invade the intestinal mucosa by interacting primarily with enterocytes and not with M cells.

Animals↗

Exercise-induced myocardial ischaemia in women: factors affecting prevalence.

Coronary artery disease (CAD) is a major health care challenge, and is the leading cause of death amongst women. Both the delay in the clinical manifestations of CAD and 'atypical' symptomatology in women complicates both diagnosis and treatment strategies in this population. It appears that the age-adjusted prevalence of all-cause angina (effort, unstable, etc.) appears to be greater in women than men, although stenotic lesions are demonstrated less frequently. There are a number of factors that complicates the diagnosis and identification of CAD in women, including more diffuse anginal symptoms, a lower initial detection rate of myocardial ischemia by traditional methods, lower rates of interventional procedures, and lastly, potential differences in the pathophysiology of myocardial ischemia. The lower sensitivity and specificity of many diagnostic techniques including ECG and various imaging technologies contributes significantly to these findings. The increased presence of syndrome X in post-menopausal women may reflect an increased likelihood of microcirculatory disease, where the 'gold standard' angiography fails to detect the presence of disease. Thus nonepicardial coronary stenotic disease may be largely undetected by most studies, rendering many positive ECG stress results unverifiable. The increased co-morbidity seen with CAD in women further complicates diagnosis and interventional results. Combined, these factors act to falsely lower the post-test likelihood of disease in women, adding to the existing gender bias in the diagnosis and referral rates for treatment of CAD in women. The lower precision of disease detection in women contributes to the perception that women have less exertional angina than men, despite evidence to the contrary.

Angina Pectoris↗

Attachment of bacteria to beef from steam-pasteurized carcasses.

The extent to which a bacterial cocktail containing equal numbers of Pseudomonas fragi NCTC 10689, Listeria monocytogenes BL5/2, Salmonella Typhimurium LT2, and Escherichia coli JM 109 attached to loin surface cuts (7 by 5 cm) derived from steam-pasteurized beef carcasses has been evaluated. The extent of attachment was categorized as loosely attached (removed by rinsing), firmly attached (released by stomaching), and irreversibly bound. No significant difference (P > 0.10) in the attachment of bacteria to steam-pasteurized carcasses was found compared with control loin samples that had received no treatment. No significant difference (P > 0.05) was also found in the attachment strength between the different bacterial species tested. Most bacteria inoculated onto the loin cuts were reversibly bound, since they had been removed by rinsing and stomaching. The irreversible attachment of bacteria to loin cuts was found to vary significantly (P < 0.01) among the different carcass sets used but was independent of whether the carcass had undergone steam pasteurization treatment. Use of a bioluminescent strain of E. coli showed that cells bound preferentially to cut edges and convoluted areas on the loin surface and could not be removed by rinsing. The possible mechanisms of bacterial attachment and the suitability of steam pasteurization to remove contamination incurred during slaughter are discussed.

Animals↗

A randomized, double-blind comparative trial evaluating the safety of liposomal amphotericin B versus amphotericin B lipid complex in the empirical treatment of febrile neutropenia. L Amph/ABLC Collaborative Study Group.

In this double-blind study to compare safety of 2 lipid formulations of amphotericin B, neutropenic patients with unresolved fever after 3 days of antibacterial therapy were randomized (1:1:1) to receive amphotericin B lipid complex (ABLC) at a dose of 5 mg/kg/d (n=78), liposomal amphotericin B (L Amph) at a dose of 3 mg/kg/d (n=85), or L Amph at a dose of 5 mg/kg/d (n=81). L Amph (3 mg/kg/d and 5 mg/kg/d) had lower rates of fever (23.5% and 19.8% vs. 57.7% on day 1; P<.001), chills/rigors (18.8% and 23.5% vs. 79.5% on day 1; P<.001), nephrotoxicity (14.1% and 14.8% vs. 42.3%; P<.01), and toxicity-related discontinuations of therapy (12.9% and 12.3% vs. 32.1%; P=.004). After day 1, infusional reactions were less frequent with ABLC, but chills/rigors were still higher (21.0% and 24.3% vs. 50.7%; P<.001). Therapeutic success was similar in all 3 groups.

Adolescent↗

Intramuscular injection of a plasmid vector expressing human apolipoprotein E limits progression of xanthoma and aortic atheroma in apoE-deficient mice.

Apolipoprotein-E (apoE) protects against coronary artery disease via hepatic removal of atherogenic remnant lipoproteins, sequestration of cholesterol from vessel walls and local anti-oxidant, anti-platelet and anti-inflammatory actions. ApoE gene transfer may thus ameliorate a hyperlipidaemic profile and have beneficial effects at lesion sites to prevent or regress atherosclerosis, a concept endorsed by adenoviral-mediated hepatic expression studies. Here, using plasmid vectors expressing allelic human apoE2 or apoE3 isoforms, skeletal muscle was evaluated as an effective secretory platform for apoE gene augmentation. Transfected myoblasts and myotubes were found to efficiently secrete recombinant apoE in vitro as spherical 10-16 nm lipoprotein particles with pre-beta mobility. Intramuscular plasmid injection in apoE(-/-) mice, which develop spontaneous atherosclerotic plaque and xanthoma resulted in expression and secretion of apoE. Human apoE mRNA was detected by RT-PCR in injected muscles and, although concentrations of apoE3, which is rapidly cleared from plasma, were near ELISA detection limits, levels of plasma apoE2 were measurable (17.5 +/- 4.3 ng/ml). To assess whether muscle-based expression of apoE2 could inhibit atherogenesis, long-term follow-up studies were conducted. Although hyperlipidaemia was not reduced in treated animals, end-point pathology showed clear retardation of atherosclerotic and xanthomatous lesions. Up to 9 months following a single apoE2 plasmid administration, atherosclerotic lesion coverage in proximal aorta was significantly reduced by 20-30% (P < 0.01), whereas development of gross dorsal xanthoma (>5 mm diameter) was effectively reduced to zero. We conclude that expression of apoE from ectopic muscle sites has therapeutic potential to limit progression of atherosclerosis.

Animals↗

Mycobacterium avium enters intestinal epithelial cells through the apical membrane, but not by the basolateral surface, activates small GTPase Rho and, once within epithelial cells, expresses an invasive phenotype.

Mycobacterium avium is a common pathogen in AIDS patients that is primarily (but not exclusively) acquired through the gastrointestinal tract, leading to the development of bacteraemia and disseminated disease. To cause infection through the gut, binding and invasion of the intestinal epithelial barrier are required. To characterize this process further, we determined the cell surface(s) (basolateral vs. apical membrane) that M. avium interacts with in intestinal mucosal cells in vitro. The level of binding and invasion of both HT-29 and Caco-2 intestinal cell monolayers by M. avium were similar when the assay was performed with control medium in the presence of Ca2+ (when only the apical surface was exposed), with Ca2+-depleted medium or with Ca2+-depleted medium + 1 mM EGTA (exposure of both apical and basolateral membranes), suggesting that the bacterium enters the apical surface of the epithelial lining. These observations were confirmed by assays in a transwell system and by using fluorescent microscopy. Real-time video microscopy showed that M. avium entry was not associated with membrane ruffling and the use of pharmacological inhibitors of the small GTPases demonstrated that M. avium invasion is dependent on the activation of the small GTPases Rho, but not on Rac or Cdc42. Passage of M. avium through HT-29 cells led to a phenotypic change (intracellular growth; IG) that was associated with a significantly greater (between five- and ninefold) ability to bind to and invade new monolayers of epithelial cells or macrophages when compared with the invasion by M. avium grown on agar (extracellular growth; EG). IG phenotype invasion of HT-29 cells also takes place only by the apical surface. M. avium enters intestinal epithelial cells by the apical surface and, once within the cells, changes phenotype, becoming more invasive towards both macrophages and other epithelial cells.

AIDS-Related Opportunistic Infections↗

Interaction of Mycobacterium avium with human monocyte-derived dendritic cells.

The mechanism by which mycobacteria elicit class I-restricted T-cell responses remains undefined because these organisms have been shown to reside exclusively within membrane-bound vesicles in macrophages (Mphi), their primary host cells. We studied the interaction of M. avium with dendritic cells (DC) because they are the most potent antigen-presenting cells and are abundant at M. avium infection sites. We observed that both DC and Mphi, generated from human peripheral blood monocytes by short-term culture, internalized M. avium. The onset of programmed cell death and the percentage of apoptotic cells in infected DC and Mphi were comparable. However, following infection, DC secreted significantly larger amounts of interleukin-12, but not interleukin-1beta, than infected autologous Mphi. Further analysis of infected cells showed that while phagosomes failed to acidify in both M. avium-infected DC and Mphi, bacilli grew more slowly in DC. Electron microscopy studies revealed that M. avium resided within endocytic vacuoles in both cell types. The vacuolar membrane surrounding some bacilli in approximately 10% of the vacuoles in DC possessed several breaks. The importance of this finding will have to be addressed in future studies.

Apoptosis↗

Full-fat cream.

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Famous Persons↗

Cognitive deficits in a genetic mouse model of the most common biochemical cause of human mental retardation.

Phenylalanine hydroxylase (Pah)-deficient "PKU mice" have a mutation in the Pah gene that causes phenylketonuria (PKU) in humans. PKU produces cognitive deficits in humans if it is untreated. We report here the first evidence that the genetic mouse model of PKU (Pah(enu2)) also produces cognitive impairments. PKU mice were impaired on both odor discrimination reversal and latent learning compared with heterozygote littermates and with wild-type mice of the same BTBR strain. A small container of cinnamon-scented sand was presented on the right or left, and nutmeg-scented sand was presented on the other side; left-right location varied over trials. Digging in sand of the correct scent was rewarded by finding phenylalanine-free chocolate. To prevent scent cuing, new containers were used on every trial, and both containers always contained chocolate. Digging in the incorrect choice was stopped before the chocolate was uncovered. Once criterion was reached, the other scent was rewarded. PKU mice were impaired on reversals 2, 3, and 4. They were also impaired in latent learning. On day 1, half the mice were allowed to explore a maze and discover the location of water. On day 2, all mice were water-deprived and were placed in the maze. Whereas pre-exposed wild-type and heterozygous mice showed evidence that they remembered the location of the water and hence could find the water faster on day 2, pre-exposed PKU mice showed no significant benefit from their pre-exposure on day 1.

Animals↗

Lung-sparing surgery after penetrating trauma using tractotomy, partial lobectomy, and pneumonorrhaphy.

OBJECTIVE: To evaluate the role of lung-sparing surgical techniques in the surgical management of penetrating pulmonary injuries. DESIGN: Retrospective case series. SETTING: Academic level I trauma center. PATIENTS AND METHODS: Forty patients underwent thoracic surgery for penetrating lung injuries during a 63-month period from January 1993 to March 1997. Five (12.5%) underwent anatomical lobectomy, 3 (7.5%) pneumonorrhaphy, 9 (22.5%) stapled wedge resection, and 23 (57.5%) stapled tractotomy. In total, 34 patients (85%) were treated with stapling techniques (1 anatomical lobectomy, 1 pneumonorrhaphy, 9 stapled wedge resections, and 23 stapled tractotomies) and 35 (87.5%) underwent had lung-sparing surgery for trauma. RESULTS: Morbidity and mortality rates were 40% and 5%, respectively. Patients who underwent anatomical lobectomy required longer mechanical ventilatory support, intensive care unit stay, and hospital stay and had a higher morbidity rate compared with patients who underwent lung-sparing surgery for trauma but had central and extensive pulmonary injuries. Stapled tractotomy was efficient in controlling bleeding and bronchial leaks, but, in 3 patients, parts of the divided lung parenchyma were devascularized and had to be resected. CONCLUSIONS: Lung-sparing surgery for trauma with the use of staplers can be used in the majority of patients with penetrating pulmonary injuries requiring operation. Stapled tractotomy is a rapid and effective method for controlling hemorrhage and air leaks.

Adult↗

Ultrastructural smooth muscle ontogeny of the rat bladder.

The transmission electron microscope characteristics of developing rat bladder smooth muscle are described at 14 and 18 days of gestation, birth, and adulthood. Caveolae, microfilaments, and dense bodies increase during smooth muscle development. Collagen content in the extracellular matrix also increases. These changes may reflect increased bladder emptying in the rat, and also allow for comparison of smooth muscle cells in studies of bladder wound healing and tissue substitutes.

Aging↗

Inelastic demand for alcohol in rats.

RATIONALE: For the purpose of investigating the determinants of preference for alcohol, it would be advantageous to use a procedure in which the subjects had concurrent access to alcohol and an isocaloric food. However, in widely used animal models, the introduction of a weak sucrose solution markedly reduced alcohol consumption. In contrast, when alcohol was sweetened, rats defended high baseline levels of alcohol intake despite access to chow, 10% sucrose, and increases in body weight that markedly reduced food consumption. Under these conditions, certain pharmacological treatments selectively reduced alcohol consumption. The present experiment further tests the generality of the contrast between food and sweetened alcohol consumption in rats. OBJECTIVE: To test if rats will defend baseline levels of alcohol consumption when (1) the competing reinforcer is an isocaloric, preferred food and (2) when the cost of defending alcohol entails a decrease in food consumption as well as an increase in response output. METHODS: The rats had access to a 10% alcohol plus 0.25% saccharin solution and an isocaloric, 14.8% Polycose solution in a two-lever, choice procedure. In the initial condition, the response requirement for each drink was set at five responses (variable-ratio 5); in subsequent conditions the variable-ratio values were increased to 7.5, 10, 15, and 30 responses. RESULTS: In the initial condition, the rats drank twice as much Polycose as alcohol. However, with increases in the variable-ratio requirements, Polycose consumption systematically decreased, whereas sweetened alcohol consumption remained at its baseline level or above in all but the variable-ratio 30 condition. CONCLUSIONS: Rats defended baseline alcohol consumption but not baseline food consumption. As alcohol and food consumption can be dissociated in humans, research on the mechanisms that mediate alcohol regulated preference in rats may shed light on the mechanisms that control human alcohol consumption.

Alcohol Drinking↗

Cancer chemotherapy, biodiversity, public and private property: the case of the anti-cancer drug taxol.

The drug taxol has been hailed by many in the cancer community as a major breakthrough in the treatment of cancer. It has already been approved in use against ovarian and advanced breast cancer in many countries worldwide. Taxol has also promoted profound debates in the policy arena not, as one might expect, because of the characteristics or purposes of the drug itself, but because of other far-reaching effects. Taxol is a complex compound found in the bark of the Pacific yew tree, primarily in Oregon and Washington in the USA. The bark was first collected in 1962 and cytotoxicity demonstrated in 1964. Yet it was not until 1989 that the first results of clinical trials were reported. In the US taxol was then rushed through the Food and Drug Administration's regulatory procedures, approval being granted for use in refractory ovarian cancer in 1992. The controversies surrounding taxol surfaced in 1989 and grew substantially over the next few years. In this paper we examine two principal controversies concerning taxol, the first of which focused on apparent conflicts between the needs of environmental protection and those of cancer chemotherapy. Although the media portrayed this as a clash of interests between the environment and people with cancer, we argue that it was an attempt to increase lay participation in biomedical decision making and policy formulation. The second controversy was between health policy and the transfer of public scientific property to the corporate sector. The pharmaceutical company Bristol-Myers Squibb was given exclusive rights to provide taxol from Pacific yew trees under a Co-operative Research and Development Agreement signed in 1991. While this was seen to be in the US Government's (as well as the company's) interest, it provoked a public reaction questioning the terms and consequences of the transfer of publicly generated scientific knowledge to the private sector.

Antineoplastic Agents, Phytogenic↗

Presurgical serum albumin levels predict survival time from glioblastoma multiforme.

To determine whether serum albumin levels, before first surgery, predict time until death, 24 glioblastoma multiforme patients newly diagnosed at Ohio State University and Cleveland Clinic Foundation Hospitals between 1993 and 1995 were followed until 1996. Patients with presurgical serum albumin levels below 3.4 mg/dL survived an average (median) of 62 days (95% confidence interval (CI): 34, 135 days) after surgery. Those with serum albumin levels of at least 3.4 mg/dL survived an average of 494 days (95% CI: 241, 624 days). The association between serum albumin level and time until death persists when adjusted for demographic and treatment variables using Cox proportional hazards regression. Adjusted hazard ratios, by quartile of presurgical serum albumin level, are: 1.0, 1.2, 0.1, 0.1 (P-value for trend test = 0.007). In addition to providing a prognostic indicator, presurgical serum albumin levels can be used to evaluate the success of randomization of clinical trials for glioblastoma multiforme therapies. Our findings are consistent with results seen for tumors at other sites. We speculate that our results may be attributable to an association between low serum albumin levels and physiological events associated with angiogenesis.

Female↗

Role of complement receptors in uptake of Mycobacterium avium by macrophages in vivo: evidence from studies using CD18-deficient mice.

Mycobacterium avium is an intracellular pathogen that has been shown to invade macrophages by using complement receptors in vitro, but mycobacteria released from one cell can enter a second macrophage by using receptors different from complement receptors. Infection of CD18 (beta(2) integrin) knockout mice and the C57 BL/6 control mice led to comparable levels of tissue infection at 1 day, 2 days, 1 week, and 3 weeks following administration of bacteria. A histopathological study revealed similar granulomatous lesions in the two mouse strains, with comparable numbers of organisms. In addition, transmission electron microscopy of spleen tissues from both strains of mice showed bacteria inside macrophages. Our in vivo findings support the hypothesis that M. avium in the host is likely to use receptors other than CR3 and CR4 receptors to enter macrophages with increased efficiency.

Animals↗