Qualitative assessment of the emotional and behavioural responses of haemophilia A carriers to negative experiences in their medical care.

Previous discussions with haemophilia A (HA) carriers suggested that carriers may experience inappropriate care, resulting in poor relationships with healthcare providers (HCPs; principally physicians and nurses), and unfortunate and extreme emotional and behavioural responses. This was a qualitative study to explore medical experiences of HA carriers and their emotional and behavioural responses. Eleven HA carriers and five Haemophilia Treatment Centre nurses were interviewed. Themes were identified using QSR NVivo 8.0. Carriers and nurses reported HA-related bleeding symptoms in carriers, including life-threatening haemorrhage following injury or medical intervention. Menorrhagia was common and distressing. Negative carrier experiences were related in the determination of genotypic and phenotypic status, management, precautions and HCP attitude, including dismissing carriers' symptoms, concerns or requests for care. Carriers responded with mistrust, lost confidence, disappointment, fear, anxiety, doubt of self or child, discussing experiences, avoidance of healthcare and self-treatment. Dismissive HCP attitudes, ignorance about bleeding disorders in women and unique aspects of the carrier population appear to make errors more likely. This study indicates that carriers experience inappropriate care and encounter dismissive attitudes, and respond emotionally and behaviourally. Our model suggests that systematic medical errors aggravate a negative feedback loop leading to negative emotional and behavioural responses and worsening carrier care. Improved carrier care policies and increased awareness of women's bleeding disorders may improve this situation. Further research is needed to determine whether the themes identified in this study accurately reflect the experiences of carriers in general.

Captopril removal by rabbit lung in vivo.

Removal of [14C]captopril by the lungs of anesthetized rabbits was measured by the multiple indicator dilution technique. After coinjection of indocyanine green (ICG) and [14C]captopril into the jugular vein of anesthetized rabbits, serial blood samples were collected from the carotid artery and each was analyzed for its content of both substances. Percent removal (R) of captopril after its initial injection of 10 nmoles captopril/kg (calculated at the peak of the ICG outflow curve) was 40.2 +/- 2.5 (S.E.M.) and was significantly greater than R after a second injection of 10 nmoles captopril/kg (20.1 +/- 2.4) 1 hr later. Removal of 70 nmoles captopril/kg (5.8 +/- 3.0 after first injection, 6.4 +/- 2.2 after second injection) was significantly lower than R of 10 nmoles captopril/kg. During a single pulmonary passage of either dose of captopril, R was inversely related to the calculated fractional concentration of intravascular captopril. Pulmonary metabolism of the angiotensin converting enzyme (ACE) substrate [3H]benzoyl-Phe-Ala-Pro [( 3H]BPAP) was 70.1 +/- 1.7% in the absence of captopril, and was reduced significantly to 27.4 +/- 2.4% by 10 nmoles captopril/kg and 7.6 +/- 0.2% by 6 mumoles BPAP/kg. BPAP (6.4 +/- 0.6 mumoles/kg) significantly reduced R of the first and second injections of 10 nmoles captopril/kg but this effect was selective, since BPAP did not reduce pulmonary removal of [14C]serotonin. These data indicate that pulmonary removal of captopril in vivo is saturable and may primarily reflect binding of the drug to pulmonary endothelial ACE.

Characterization of beta-adrenergic receptors in cultured human and bovine endothelial cells.

We used radioligand binding methods to characterize beta-adrenergic receptors on endothelial cells cultured from adult human iliac vein (HIVE) and bovine fetal aorta (BFAE). For comparison, we also studied the well-characterized C6 glioma cell line (C6). Both human and bovine endothelial cells showed specific saturable binding of [125I]iodopindolol. There was no difference in the binding affinity (KD) of iodopindolol to membranes from the three cell types. However, the beta-receptor density (Bmax) was greater on HIVE cells and BFAE cells than on C6 cells. Displacement of ligand from HIVE and BFAE cells by zinterol or from BFAE cells by ICI 89,406 was consistent with binding to the beta 2-subtype. In contrast, displacement of ligand from C6 cells by zinterol or ICI 89,406 was consistent with binding to both beta 1- and beta 2-subtypes. Exposing BFAE cells in culture to 10 microM isoproterenol for 6 h resulted in a 55% decrease in Bmax without a change in KD. We conclude that 1) human and bovine endothelial cells in culture contain a substantial population of beta-adrenergic receptors, which are predominantly of the beta 2-subtype, and 2) endothelial beta-receptors exhibit downregulation by beta-agonists in culture.

Chromatographic demonstration of reversible changes in endothelial permeability.

This report describes a new in vitro method for measuring the diffusional permeability of an endothelial monolayer and its use in investigating the modulation of permeability by various agents, e.g., isoproterenol, propranolol, dibutyryl adenosine 3',5'-cyclic monophosphate (cAMP), and cytochalasin D. To determine permeability, tracers of different molecular weights were applied simultaneously on a chromatography column containing confluent endothelial cells cultured on porous microcarrier beads. The Sangren-Sheppard model was used to determine the permeability of the endothelial monolayer from the tracer elution profiles. For six radiolabeled tracers the mean (+/- SD) permeabilities (cm/s x 10(-5)) in order of increasing tracer molecular weight were [3H]water, 82.0 +/- 28.8; [14C]urea, 49.5 +/- 9.5; [14C]mannitol, 13.3 +/- 4.7; [14C]-sucrose, 14.1 +/- 2.5; [3H]polyethylene glycol (900 mol wt), 4.80 +/- 1.61; and [3H]polyethylene glycol (4,000 mol wt), 1.97 +/- 1.01. These permeabilities deviate less from in vivo values than those obtained in other in vitro systems and are 10 times higher than in vivo estimates. The values were reproducible for up to the 4 h tested. Modulation of endothelial monolayer permeability was studied in a separate series of experiments. The beta-adrenergic agonist isoproterenol (10(-6) M) decreased the permeability to mannitol by 36% and to polyethylene glycol (900 mol wt) by 49%; in both instances the decrease in permeability was reversed by propranolol. Propranolol alone had no effect. Dibutyryl cAMP (10(-3) M) decreased the permeability to mannitol by 40% and to polyethylene glycol by 47%; permeability returned to base line when dibutyryl cAMP was removed. Cytochalasin D (1 microgram/ml) increased permeability by 350% for mannitol and 380% for polyethylene glycol; the permeability change was reversed after removal of cytochalasin D. The results indicate that cell-column chromatography is a powerful method that can be used to characterize the permeability of endothelial monolayers and to investigate permeability changes produced by various agents.

Airway smooth muscle selectivity of the muscarinic antagonist DAC 5945 in vivo.

We investigated the M3/M2 antagonist selectivity of [N-iminomethyl-N'-[(2-hydroxy-2-phenyl-2-cyclohexyl)-ethyl] piperazine HCI (DAC 5945) in vivo. ED50 values for reversal of methacholine-induced bronchoconstriction and bradycardia by muscarinic antagonists were determined in anesthetized and ventilated guinea pigs. Atropine, ipratopium, pirenzepine and diphenyl-acetoxy-4-methylpiperidine methiodide (4-DAMP) were non-selective, whereas methoctramine was cardioselective. In contrast, DAC 5945 was a more potent muscarinic antagonist in the airways than in the heart, demonstrating M3/M2 selectivity in vivo.

Methoctramine induces nonspecific airway hyperresponsiveness in vivo.

We investigated the effects of subtype-selective muscarinic receptor antagonists upon aerosol antigen-induced bronchoconstriction in anesthetized guinea pigs. Neither pirenzepine (muscarinic M1 receptor-selective), 4-methylpiperidine methiodide (4-DAMP, muscarinic M3 receptor-selective), [N-iminomethyl-N'-[(2-hydroxy-2-phenyl-2-cyclohexyl)-ethyl] piperazine HCl (DAC-5945, muscarinic M3 receptor-selective), ipratropium or atropine inhibited bronchoconstriction, but methoctramine (muscarinic M2 receptor-selective) produced a dose-dependent increase in bronchoconstriction (up to 46%). Methoctramine also produced increases in bronchoconstriction induced by aerosols of histamine (up to 45%) and platelet activating factor (up to 118%), demonstrating nonspecific airway hyperresponsiveness. This effect of methoctramine was not inhibited by atropine, DAC-5945 or vagotomy and could not be attributed to altered arachidonic acid metabolism or beta-adrenergic antagonism. However, propranolol prevented methoctramine-induced airway hyperresponsiveness, suggesting that this effect resulted from the reported ganglionic blocking activity of methoctramine. In conclusion, muscarinic receptors do not appear to play an important role in antigen-induced bronchoconstriction in anesthetized guinea pigs. Furthermore, caution should be exercised in using methoctramine to characterize the roles of muscarinic receptors in airway inflammatory responses in vivo.

Characterization of the airway smooth muscle muscarinic receptor in vivo.

We examined the bronchodilator activity of eight subtype-selective and non-selective muscarinic antagonists in anesthetized, ventilated guinea pigs bronchoconstricted by carbachol aerosols. Relative bronchodilator potencies were consistent with M3 receptor antagonism and correlated with inhibition of bladder smooth muscle contraction in vivo. We conclude that the airway smooth muscle muscarinic receptor can be functionally characterized in vivo as M3 and that it is of the same subtype as the muscarinic receptor in bladder smooth muscle.

Comparison of calcification between Bacterionema matruchotii and Actinomyces naeslundii.

The purpose of this research was to examine the requirements for proteolipid initiation of calcification in culture. Proteolipid from a calcifiable microorganism, Bacterionema matruchotii, was compared with proteolipid isolated from a non-calcifiable microorganism, Actinomyces naeslundii. Although A. naeslundii does not calcify in culture, lyophilized cells and proteolipid-containing extracts do initiate apatite formation. A. naeslundii proteolipid (ANN) differs from B. matruchotii (BMN) in concentration, apoprotein polarity, and phospholipid composition. These differences may alter the ability of ANN to nucleate apatite in the intact cell.

Hamster cheek-pouch testing of dental soft polymers.

The hamster cheek pouch provides a suitable model system for the mucous-membrane irritation testing of dental materials. Poor retention of materials or difficulties in histopathological interpretation caused by surgical artifacts have been reported in published techniques. We describe a new "pouch-in-pouch" technique for mucous membrane irritation tests. The retention rate of polymer discs was 97% and 87% at 14 and 35 days, respectively. Clear differentiation was obtained between the tissue reaction to the test materials and the surgical procedure. Polymer discs containing dibutyltin diacetate (DBTD) or dibutyl phthalate (DBP) as plasticizer resulted in epithelial changes, including epithelial atypia, early papillomas, and areas resembling dysplasia. The potentially pre-malignant nature of these changes requires further investigation.

Mechanism for the emetic side effect of xanthine bronchodilators.

The usefulness of xanthine bronchodilators in the treatment of asthma is often limited by the side effects of nausea and vomiting. We investigated the mechanism of emesis induced by xanthines, by examining the roles of phosphodiesterase (PDE) inhibition and adenosine antagonism. Theophylline, enprofylline, 8-phenyltheophylline and isobutylmethylxanthine (IBMX), as well as vehicle, were given to ferrets at doses ranging from 0.1 to 150 mg/kg i.p. The potencies of these compounds in producing emetic responses were ranked IBMX greater than enprofylline greater than theophylline greater than 8-phenyltheophylline. These results correlate well with the relative potencies of the compounds as nonselective PDE inhibitors but do not correlate with their relative potencies as adenosine A1 or A2 receptor antagonists. The emetic responses also correlate well with the previously reported potencies of these xanthines as bronchodilators in guinea pigs. We conclude that the emetic side effect of xanthine bronchodilators results from the inhibition of one or more forms of PDE rather than from adenosine antagonism.

Etiology of fibrous dysplasia and McCune-Albright syndrome.

In this paper, the etiology of monostotic fibrous dysplasia and McCune-Albright syndrome is explained. Both monostotic fibrous dysplasia and McCune-Albright syndrome are sporadically occurring disorders in which a mutation in the GNAS1 gene occurs postzygotically in a somatic cell. All cells descended from the mutated cell can manifest features of McCune-Albright syndrome or fibrous dysplasia. Cells descended from non-mutated cells develop into normal tissues. Thus, the clinical pattern is variable in distribution and appearance. More generalized vs more localized expression depend on (a) how small or how large the cell mass is during embryogenesis when the mutation occurs and (b) where in the cell mass the mutation occurs. Topics discussed include G proteins and their receptors, cycling of stimulatory G protein between active and inactive forms, and specific mutations in GNAS1. We also discuss four possibilities: (a) Are there masked mutations? (b) Are there effects of imprinting? (c) Are there non-classical mutations? and (d) Is fibrous dysplasia a neoplasm?

Hospital efforts in smoking control: remaining barriers and challenges.

BACKGROUND: This study reports the barriers and challenges for hospital tobacco control efforts after the institution of smoke-free policies. METHODS: Surveys of employees and inpatients of five hospitals in Augusta, Georgia, were conducted and evaluated 4 months after joint hospital implementation of smoke-free policies. A random sample of 1997 employees and a convenience sample of 517 inpatients returned usable surveys. RESULTS: Although attitudes to the hospital bans on smoking reflected strong support for smoke-free policies, four out of five hospitals reported significant implementation problems. Despite the bans, 49% of patients who were smokers continued to smoke while hospitalized, and almost one half of all hospitalized smokers had received no advice to quit smoking from a physician or a nurse since admission. Employees and patients both agreed that the smoke-free policies had benefited employees more than patients. CONCLUSIONS: Despite achieving a smoke-free status, there are many challenges that remain for comprehensive hospital tobacco-control efforts. Hospitals and health care professionals must remain particularly alert and attentive to the needs of patients and employees still addicted to tobacco.

Multiple mechanisms of xanthine actions on airway reactivity.

Xanthines are effective in the treatment of asthma, but the mechanism of action remains unclear. Pulmonary effects of seven xanthines, exhibiting a range of potencies as cyclic nucleotide phosphodiesterase (PDE) inhibitors and as adenosine antagonists, were investigated in anesthetized and ventilated guinea pigs. The bronchodilator effects of xanthines, determined from reversal of bronchoconstriction induced by aerosols of histamine and carbachol, correlated with their relative potencies as cyclic AMP-PDE inhibitors. The hypotensive effects of xanthines at bronchodilator doses were also consistent with PDE inhibition. Prophylactic effects of xanthines against bronchoconstriction induced by an aerosol of ovalbumin in sensitized guinea pigs, or by aerosols of leukotriene D4 and platelet-activating factor (PAF) in normal guinea pigs, occurred by a mechanism unrelated to bronchodilation and could not be readily attributed to PDE inhibition or adenosine A1/A2 receptor antagonism. There was a close association between inhibition of the responses to antigen and leukotriene D4, suggesting a common mechanism of action, but these effects gave a different profile from inhibition of the response to PAF. In addition, PAF-induced hypotension was unaffected in animals in which PAF-induced bronchoconstriction was inhibited, suggesting a mechanism other than PAF receptor antagonism. These results indicate that the bronchodilator, antiallergic and anti-inflammatory effects of xanthines occur through multiple molecular mechanisms of action, including at least one unknown mechanism. Furthermore, 8-phenyltheophylline produces these prophylactic effects at a dose that does not produce the cardiovascular or emetic side effects associated with xanthines, thereby exhibiting unique characteristics of potential therapeutic importance.

Influence of magnesium on norepinephrine-and histamine-induced contractions of pulmonary vascular smooth muscle.

We examined the effects of magnesium on contractile responses of the rabbit pulmonary artery. The contractile force was determined, after applications of norepinephrine or histamine, in a normal or Ca++-free solution containing 0 mM Mg++ or 1.2 mM Mg++. In a normal solution, Mg++ increased the EC50 value for histamine, but did not alter the EC50 value for norepinephrine or the maximum force induced by norepinephrine or histamine. Contractile responses to norepinephrine and histamine were equally reduced by a Ca++-free, Mg++-free solution, and were further reduced by a Ca++-free solution containing Mg++, but with a greater reduction in the response to histamine than in the response to norepinephrine. The results indicate that in the pulmonary artery, Mg++ alters the sensitivity to histamine but not to norepinephrine, and may differentially inhibit bound Ca++ release by norepinephrine and histamine.

Three phase contractile response of rabbit pulmonary artery to norepinephrine: influence of ruthenium red and calcium.

We recorded isometric contractile force of rabbit pulmonary artery after application of norepinephrine (50 microM), plotted semilogarithmic graphs of force development over time, and calculated rates of force development. The normal contractile response contained three phases: an initial fast, a short intermediate and a final slow. Correlation coefficients for each phase and differences between rates of force development of each phase were significant (P less than 0.05). Ruthenium red (1 mM) removed only the slow phase and significantly reduced the rates of the fast and intermediate phases. A calcium-free solution removed both the slow and intermediate phases and significantly reduced the rate of the fast phase.

Effects of repetitive stimulation by norepinephrine, histamine or potassium chloride on contractile responses of pulmonary vascular smooth muscle.

We examined consecutive contractile responses of isolated rabbit pulmonary arteries during repeated exposures to either norepinephrine, histamine or KC1, with washout and relaxation between trials. For each agonist, EC50 values remained constant during consecutive determinations, but the maximum force increased after the first determination. A maximum concentration of norepinephrine or histamine produced a biphasic contraction: the fast phase increased subsequent to the first determination and was retained in a calcium-free medium, while the slow phase was unaltered during consecutive determinations and was absent in a calcium-free medium. We conclude that in the rabbit pulmonary artery: the initial contractile response is a useful control for studies of sensitivity but not of maximum activity; there may be a nonspecific increase in the availability of intracellular calcium after the initial contraction and relaxation, and desensitization or tachyphylaxis to these agonists does not occur.

Human papillomavirus type 16 in an oral squamous carcinoma and its metastasis.

DNA was extracted from fresh frozen tissues of eight patients with primary oral squamous carcinoma. Samples of normal oral mucosa were available in seven cases and metastatic tumor in two cases. The samples were probed for human papillomavirus types 16 and 18 by Southern hybridization. In one case of squamous carcinoma of the floor of the mouth, human papillomavirus type 16 was identified in the primary tumor and a lymph node metastasis, but it was not detectable in normal oral mucosa from this patient. Human papillomavirus DNA was not detected in any other sample of primary tumor, metastasis, or normal oral mucosa. Restriction enzyme digests of the human papillomavirus positive primary tumor and its metastasis revealed that the viral DNA was identical to the prototype human papillomavirus type 16 and present at 50 to 100 copies per cell in an episomal state with no evidence of integration into the host DNA. Compared to the human papillomavirus DNA in the primary tumor, the viral DNA in the metastasis was of the same type, in the same physical state, and at the approximately the same copy number. The consistent maintenance of human papillomavirus DNA in metastases from human papillomavirus positive primary tumors supports the hypothesis that human papillomaviruses are cofactors in the pathogenesis of some carcinomas.