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PubMed1991

Influence of anesthesia, postanesthetic state, and restraint on superior mesenteric arterial flow in normal rats.

To exclude possible confounding effects of anesthesia on splanchnic hemodynamics, two different awake postanesthetic models (PAM), restrained and unrestrained, have been used. However critical analysis of the splanchnic hemodynamic state in these models is not available. We conducted experiments using chronically implanted pulsed-Doppler flow probes on the superior mesenteric artery (SMA) in ketamine-anesthetized and in postanesthetic restrained and unrestrained normal rats. Baseline values of mean SMA flow were compared with those under anesthesia (30 min), PAM (restrained or unrestrained at 90 and 150 min), and reanesthesia. Sham-anesthetized unrestrained animals provided control values. The same animals (n = 7) underwent the restrained, unrestrained, and control experiments at least 5 days apart. Ketamine anesthesia did not significantly alter mean SMA flow (89 +/- 9% of baseline) compared with sham-anesthetized controls (99 +/- 9%). Mean SMA flow in both PAM, restrained and unrestrained, had a significant (P less than 0.05) decrease at 90 min (78 +/- 8 and 83 +/- 12%) and at 150 min (68 +/- 14 and 78 +/- 14%) when compared with baseline and control. Reanesthesia returned SMA flows to baseline values (91 +/- 16%). The variability of mean SMA flow was significantly increased in both PAM. Maximum variability was observed in the restrained model (69 +/- 32%). These results indicate 1) that ketamine anesthesia does not significantly alter SMA flow and 2) that both the restrained and unrestrained PAM exhibit significant alterations of the splanchnic circulation for at least 2 h after complete recovery from anesthesia. Thus, in the absence of critical evaluation, results of splanchnic hemodynamic studies with these models should be questioned.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗

PubMed1999

Immunostaining of the estrogen receptor in conjunctival primary acquired melanosis.

Conjunctival primary acquired melanosis (PAM) is a frequent precursor of conjunctival melanoma. Since there is indirect evidence that the conjunctiva is an estrogen-responsive tissue, and since it was suspected that estrogen has a role in the etiology of melanoma, we decided to evaluate whether PAM may be responsive to estrogen. Formalin-fixed, paraffin-embedded sections from 13 cases of PAM and 2 cases of conjunctival melanoma were immunostained with an estrogen-receptor (ER)-specific antibody. All lesions and the normal conjunctival tissue adjacent to the lesions were found to be ER negative. It is concluded that PAM and normal conjunctiva are not sensitive directly to estrogen. When considering previously reported data, it is conceivable that the normal conjunctiva, but not PAM, is indirectly affected by estrogen.

Adolescent↗

PubMed1993

Induction and characterization of mast cell colonies by culture supernatant of retinoic acid-treated mouse keratinocytes.

The retinoic acid-stimulated mouse-transformed epidermal cell line Pam 212 generated soluble mediators (RA-Pam sup) which showed mast cell-proliferating activity and induced mast cell-like colonies from bone marrow cells. Both mucosal-type and connective tissue-type mast cells were demonstrated on histochemical analysis. The 3T3 fibroblast cell line or human trichilemmomal cell line (TL1) also generated similar molecules on retinoic acid stimulation. Anti-stem cell factor antibody presented a rather more potent inhibitory activity on RA-Pam sup-dependent mast cell colony formation than did anti-IL3 and -IL4 antibodies. RA-Pam sup only induced mast cell colonies in semisolid culture and failed to promote mast cell growth in a suspension culture. In addition, mast cell colonies showed close contact with fibroblast-like cells on the methylcellulose plate, but this finding was not observed in culture without RA-Pam sup.

Animals↗

PubMed1988

Thoracic gas volume measurements in chronic obstructive pulmonary disease by low frequency ambient pressure changes.

The validity of a new method for measuring thoracic gas volume (Vtg) was studied in 18 bronchitic patients with mild to severe airway obstruction. The method entailed submitting the subject to very slow sinusoidal variations of ambient pressure (delta Pam) and studying the relationship between delta Pam and the resulting gas displacement at the mouth (delta Vaw): Vtgapc = PB.delta Vaw/delta Pam.cos phi, where PB is barometric minus alveolar water vapor pressure, and phi is the phase angle between Pam and Vaw. delta Pam of 40 cm H2O at 0.05 Hz were achieved by placing the subject in a 410-I body chamber connected to a large stroke volume reciprocating pump. Pam and Vaw were processed digitally by Fourier transform to obtain their amplitude ratio and phase angle at the frequency of interest. Vtg was also measured by body plethysmography (Vtgplet) during slow panting maneuvers (0.79 +/- 0.19 Hz) and also in order to detect any artifactual frequency dependence at a higher panting frequency (1.71 +/- 0.27 Hz); the agreement between the 2 estimates in all subjects (r = 0.975) suggested that Vtgplet could be taken as a valid reference. Functional residual capacities derived from Vtgapc and Vtgplet were not significantly different (5.113 +/- 1.198 versus 5.260 +/- 1.328 L) and were highly correlated (r = 0.915). Intermethod differences averaged 1.7 +/- 10.5% and were not significantly correlated to functional indices. We conclude that the new method provides accurate Vtg values in patients with chronic airway obstruction.

Adult↗

PubMed1978

Identification of a receptor for complement on the guinea pig alveolar macrophage membrane.

The present study was undertaken in an attempt to demonstrate the presence of a receptor for complement on the membrane of guinea pig alveolar macrophages (PAM). When target cells were prepared using mouse serum as the complement source, no attachment or ingestion of the target cell by guinea pig PAM was observed. When fresh autologous guinea pig serum was used as the complement source, attachment and ingestion of the target cell by PAM were observed. The results of additional experiments demonstrated that the attachment of these target cells was mediated by a complement receptor. These results demonstrated that like human PAM, guinea pig PAM do possess a membrane receptor for complement.

Animals↗

PubMed1981

Human alveolar macrophages: a lesion in arachidonic acid metabolism in cigarette smokers.

Human pulmonary macrophages (PAM) recovered from young cigarette smokers and from age- and sex-matched subjects who had never smoked were used to investigate arachidonic acid metabolism. The uptake of radiolabeled arachidonic acid by PAM obtained from smokers and nonsmokers was not significantly different. The phagocytic indexes of the smoker and nonsmoker macrophages were 17.4 X 3.9% and 18.5 +/- 5.0%, respectively. Both smoker and nonsmoker macrophages produced prostaglandin E2 (PGE2), thromboxane B2 (TXB2) and prostaglandin F2 alpha (PGF2 alpha). A significant decrease in PGE2 and TXB2 synthesis but not in PGF2 alpha synthesis by the smoker PAM compared PAM compared with the nonsmoker PAM was observed using 2 different assays to measure prostaglandin production. Nonsmoker macrophages produced 644 +/- 128,239 +/- 53, and 29 +/- 12 ng/1.5 X 10(6) cells of PGE2, TXB2, and PGF2 alpha, respectively, whereas smoker macrophages synthesized 168 +/- 20, 41 +/- 3, and 17 +/- 1 ng/1.5 X 10(6) cells, as measured by radioimmunoassay. Similar differences were observed using isotopic assays. A cigarette-smoke-induced lesion in phospholipid hydrolysis or the mechanism regulating phospholipid hydrolysis seem most consistent with these findings.

Adult↗

PubMed1983

Metabolism of 25-hydroxyvitamin D3 by cultured pulmonary alveolar macrophages in sarcoidosis.

Metabolism of [3H]25-hydroxyvitamin D3(25-OH-D3) was studied in primary cultures of pulmonary alveolar macrophages (PAM) from seven patients with sarcoidosis and two patients with idiopathic pulmonary fibrosis. Production of a [3H]1,25-dihydroxyvitamin D3 (1,25-[OH]2-D3)-like metabolite of [3H]25-OH-D3 was detected in lipid extracts of cells from five patients with sarcoidosis. Synthesis of this compound in vitro was limited to viable PAM and was greatest in cells derived from a patient with hypercalcemia and an elevated serum concentration of 1,25-dihydroxyvitamin D. The tritiated PAM metabolite coeluted with authentic 1,25-(OH)2-D3 in three different solvent systems on straight-phase high performance liquid chromatography (HPLC) and demonstrated binding to extracted receptor for 1,25-(OH)2-D3, which was identical to that of commercially available [3H]1,25-(OH)2-D3 of comparable specific activity. Incubation of PAM with high concentrations of 25-OH-D3 resulted in production of an unlabeled metabolite that co-chromatographed with the 3H-PAM metabolite on HPLC and that was bound with high affinity by both the specific receptor for 1,25-(OH)2-D3 and antiserum to 1,25-(OH)2-D3.

Calcifediol↗

PubMed1994

Evaluation of pulmonary arterial pressure in acute pulmonary embolism.

Twenty-six patients with acute pulmonary embolism underwent hemodynamic examination. Twenty-three of the patients were free of prior cardiopulmonary diseases. The other 3 patients had prior history of cardiac disease. In the 23 patients, the mean pulmonary arterial pressure (PAm) ranged from normal range to 35 mmHg at the time of the embolic event and generally declined within ten days after the embolic event. However, in the 3 patients with a history of disease, reelevation of PAm was observed during the pressure monitoring. PAm was positively correlated with the extent of pulmonary vascular obstruction (r = 0.863, p < 0.01) and also with mean right atrial pressure (RAm, r = 0.830, p < 0.01). In the presence of prior cardiac disease, PAm in patients with normal preembolic PAm increased proportionally to the extent of obstruction. Continuous hemodynamic monitoring is valuable for estimating the degree of embolic obstruction and the speed of embolus resolution and for detecting new embolic episodes in some cases.

Acute Disease↗

PubMed2001

Parenting alliance: a multifactor perspective.

The Parenting Alliance Measure (PAM) provides an operational representation of Weissman and Cohen's theory of parenting that has both clinical and research applications. The PAM is a 20-item, self-report instrument that measures the strength of the perceived alliance between parents of children ages 1 to 19 years. Multigroup confirmatory factor analysis was used to examine whether the PAM measures the same constructs for mothers and fathers. In addition, a formal comparison between a one- and two-factor solution was conducted, and the invariance of parameter estimates for the preferred model was tested for mothers and fathers. Results indicated that the PAM measures the same dimensions for these two groups. A formal comparison between the one- and two-factor solutions favored the less parsimonious two-factor model. At the same time, the relationship between these constructs was sufficiently high to warrant interpretation of an overall parenting alliance score. Accordingly, results from the current investigation support two levels of interpretation on the PAM. Normative raw score conversions to percentile and standardized T scores are provided.

Adolescent↗

PubMed2003

Menkes protein contributes to the function of peptidylglycine alpha-amidating monooxygenase.

Menkes protein (ATP7A) is a P-type ATPase involved in copper uptake and homeostasis. Disturbed copper homeostasis occurs in patients with Menkes disease, an X-linked disorder characterized by mental retardation, neurodegeneration, connective tissue disorders, and early childhood death. Mutations in ATP7A result in malfunction of copper-requiring enzymes, such as tyrosinase and copper/zinc superoxide dismutase. The first step of the two-step amidation reaction carried out by peptidylglycine alpha-amidating monooxygenase (PAM) also requires copper. We used tissue from wild-type rats and mice and an ATP7A-specific antibody to determine that ATP7A is expressed at high levels in tissues expressing high levels of PAM. ATP7A is largely localized to the trans Golgi network in pituitary endocrine cells. The Atp7a mouse, bearing a mutation in the Atp7a gene, is an excellent model system for examining the consequences of ATP7A malfunction. Despite normal levels of PAM protein, levels of several amidated peptides were reduced in pituitary and brain extracts of Atp7a mice, demonstrating that PAM function is compromised when ATP7A is inactive. Based on these results, we conclude that a reduction in the ability of PAM to produce bioactive end-products involved in neuronal growth and development could contribute to many of the biological effects associated with Menkes disease.

Adenosine Triphosphatases↗

PubMed1984

Secretion and regulation of two biosynthetic enzyme activities, peptidyl-glycine alpha-amidating monooxygenase and a carboxypeptidase, by mouse pituitary corticotropic tumor cells.

Secretion of peptidyl-glycine alpha-amidating monooxygenase (PAM) activity and enkephalin convertase (a carboxypeptidase B-like enzyme) activity from AtT-20 mouse corticotrope tumor cells was compared with secretion of pro-ACTH/endorphin-derived peptides. Upon stimulation of secretion by corticotropin-releasing factor, a beta-adrenergic agonist, or barium ions, secretion of PAM activity, enkephalin convertase activity, and immunoactive hormone rose in parallel. During inhibition of stimulated secretion with glucocorticoids or cobalt ions, secretion of PAM activity, enkephalin convertase activity, and immunoactive hormone fell in parallel. No measurable secretion of cytosolic, mitochondrial, or lysosomal marker enzymes was detected, indicating that the secretion of PAM activity and enkephalin convertase activity was specific and not a result of cell damage or lysis. The kinetic characteristics, apparent mol wt, and enzymatic properties determined for the secreted enzymes were similar to those for the enzymes from secretory granules. In AtT-20 cells treated with glucocorticoids for up to 8 days, cellular levels of immunoactive ACTH/endorphin-related peptides decreased to one third of control levels. Levels of PAM activity in cell extracts declined in parallel with levels of hormone. In contrast, levels of enkephalin convertase activity, cell protein, lactate dehydrogenase, fumarase, and lysosomal carboxypeptidase did not decline in response to chronic glucocorticoid exposure.

Animals↗

PubMed1990

A role for endogenous arachidonate metabolites in the regulated expression of the 25-hydroxyvitamin D-1-hydroxylation reaction in cultured alveolar macrophages from patients with sarcoidosis.

In the human granulomatous disease sarcoidosis hypercalcemia and/or hypercalciuria result from the endogenous overproduction of 1,25-dihydroxyvitamin D [1,25-(OH)2D] by the disease-activated macrophage. Unlike the renal 25-hydroxy-vitamin D (25OHD)-1-hydroxylase, normally the sole synthetic source of the hormone in man, the 25OHD3-1-hydroxylation reaction in cultured pulmonary alveolar macrophages (PAM) from patients with sarcoidosis is subject to stimulation by the immune cytokine interferon-gamma (IFN gamma) and inhibition by the antiinflammatory glucocorticoid dexamethasone. The data presented here suggest that IFN gamma and calcium ionophore A23187 promote enhanced expression of the sarcoid PAM 25OHD3-1-hydroxylation reaction by increasing endogenous arachidonic acid metabolism through the 5-lipoxygenase pathway. Dexamethasone, an inhibitor of the cellular phospholipase-A2-arachidonic acid-generating system, and BW755C, a lipoxygenase pathway inhibitor, inhibited PAM 1,25-(OH)2D3 synthesis by 64% and 54%, respectively. Conversely, leukotriene C4, a distal metabolite in the arachidonic acid 5-lipoxygenase pathway, increased the hydroxylation reaction by 234% and restored dexamethasone-inhibited PAM 1,25-(OH)2D3 synthetic activity. The results of this study provide presumptive evidence for an important role of agonist (IFN gamma)-calcium-modulated eicosanoid metabolism in the regulated synthesis of 1,25-(OH)2D by PAM in sarcoidosis.

Arachidonate 5-Lipoxygenase↗

PubMed1990

Glucocorticoids regulate peptidyl-glycine alpha-amidating monooxygenase gene expression in the rat hypothalamic paraventricular nucleus.

Peptidyl-glycine alpha-amidating monooxygenase (PAM) is a posttranslational processing enzyme which catalyzes the formation of biologically active alpha-amidated peptides. The two major neuropeptides involved in the regulation of ACTH secretion [CRF and arginine vasopressin (AVP)], synthesized in the parvocellular part of the hypothalamic paraventricular nucleus (PVN), are amidated, and their synthesis and/or release is negatively regulated by glucocorticoids. In this study, using in situ hybridization, we have shown that PAM mRNA is abundantly expressed in the hypothalamic paraventricular and supraoptic nucleus. Surgical adrenalectomy (ADX) induced increases in PAM, CRF, and AVP mRNA in the parvocellular part of the PVN, while corticosterone treatment normalized these values. PAM and AVP gene expression were not changed in the magnocellular part of the PVN or in the supraoptic nucleus. These observations suggest that in addition to stimulation of CRF and AVP synthesis, ADX induces an increase in PAM synthesis in the PVN and, thus, support the hypothesis of increased secretion of both CRF and AVP after ADX.

Adrenalectomy↗

PubMed1996

Processing and routing of a membrane-anchored form of proneuropeptide Y.

To investigate factors governing proteolytic processing and routing of biologically active peptides in the secretory pathway, cDNAs for preproneuropeptide Y (preproNPY) and preproneuropeptide Y fused to a membrane anchor were transfected into pituitary cells. The anchor was the transmembrane and COOH-terminal cytoplasmic domain of peptidylglycine alpha-amidating monooxygenase (PAM); these domains are essential for correct routing of integral membrane forms of PAM. Like proneuropeptide Y (proNPY), the integral membrane form of proNPY was a good substrate for the endogenous prohormone convertases, yielding soluble NPY stored in regulated secretory granules. Tethering of proNPY to the membrane resulted in only a small delay in the rate of cleavage to produce mature NPY and in the arrival of NPY in regulated secretory granules. In contrast, the COOH-terminal region of proNPY remained attached to the transmembrane/COOH-terminal domain of PAM and was rerouted to the vicinity of the trans-Golgi network, where integral membrane forms of PAM are concentrated. Thus, the COOH-terminal of proNPY cannot override the signals in the PAM membrane anchor.

Animals↗

PubMed1991

Glucocorticoid receptor mRNA expression in pulmonary alveolar macrophages in sarcoidosis.

The presence of the glucocorticoid receptor was demonstrated by immunocytochemistry in pulmonary alveolar macrophages obtained by bronchoalveolar lavage. Also, GR mRNA content was determined by solution hybridization in PAM from 12 healthy volunteers and in 6 patients with sarcoidosis. No significant differences with regard to GR mRNA expression was detected between the two groups examined. For comparison, lung tissue from three patients undergoing thoracic surgery was examined and found to contain GR mRNA levels in the same range. As an indication of GR function, we also determined the mRNA levels of a glucocorticoid-regulated gene, metallothionein IIA, during basal conditions and after in vitro incubation of PAM with dexamethasone. Neither the control sample nor the dexamethasone-stimulated MTII mRNA values in PAMs differed significantly between the two groups. Solution hybridization is a rapid, sensitive and convenient assay which enables accurate and specific quantitation of GR mRNA in PAM. The GR mRNA content and basal as well as dexamethasone-induced MTII mRNA levels in PAM from patients with sarcoidosis is not significantly different from those in healthy volunteers.

Adult↗

PubMed1997

Primary amebic meningoencephalitis: a review of the clinical literature.

Primary amebic meningoencephalitis (PAM) is a rapidly progressive and potentially fatal infection frequently contracted by swimming in bodies of warm fresh water. The etiological agent in most reported cases of PAM is the ameboflagellate Naegleria fowleri. Infection with this organism closely mimics and is often mistaken for a bacterial or a viral pyogenic meningitis. Recovery is rare and depends on rapid diagnosis and treatment. Physicians treating individuals who present with an acute pyogenic meningitis should consider the diagnosis of PAM, particularly if the patient has a recent history of swimming in warm fresh water. We review the recent literature for cases of PAM and the discuss ecology of N. fowleri and the clinical presentation, diagnosis, and treatment of PAM.

Amebiasis↗

PubMed1993

Influence of growth factors on the plasminogen activator activity of avian granulosa cells from follicles at different maturational stages of preovulatory development.

Granulosa cells from the first (F1), third (F3) and fifth and sixth (F5-6) preovulatory follicles and the small yellow follicles (SYFs; diameter 6-8 mm) were cultured for 21 h in the absence and presence of murine and human epidermal growth factors, fibroblast growth factor, transforming growth factors alpha and beta-I (TGF alpha, TGF beta), platelet-derived growth factor and insulin-like growth factor-I at concentrations of 0.1-100 ng/ml. Plasminogen activator (PA) activities in the cell (PAc) and in the medium (PAm) were measured by fibrinolysis and fibrin overlay methods. Basal PAc and PAm activities were highest in cell cultures from the less mature follicles (F5-6 and SYF) and decreased as the follicles matured (F3 > F1). PAc activity was greater than PAm activity, irrespective of the stage of follicular development. All growth factors examined at the 100 ng/ml level were effective in increasing PAc and PAm activities in cultures of granulosa cells from F1 follicles. However, only TGF alpha was able to increase PA activities at lower concentrations. The stimulation of the PA activities of granulosa cells from F3 follicles was inconsistent. None of the growth factors significantly increased PA activities in granulosa cells from F5-6 follicles and SYFs, as determined by fibrinolysis. The major PAc and PAm species (characterized by fibrin overlay) had a molecular mass of about 35 kDa, which is characteristic of the urokinase type. Both assay methods detected a stimulatory effect of the growth factors on PA activities in the granulosa cells from F1 follicles. However, an increase in PA activities in cells from F3 and F5-6 follicles and SYFs was indicated only after fibrin overlay analysis. Tritiated thymidine was incorporated into the DNA of granulosa cells at all stages of follicular development and was enhanced by all growth factors, although TGF alpha and TGF beta were the most effective and had a ranked order of activity: F3, F5-6 > F1, SYF. The present findings show that, of the growth factors examined, TGF alpha may be an effective regulator of PA activity in avian granulosa cells during follicular development, in addition to its observed mitogenic action.

Animals↗

PubMed2001

The use of carbamates, atropine, and 2-pyridine aldoxime methoiodide in the protection of Artemia salina against poisoning by carbophenothion.

The acute toxicity of carbophenothion to three age classes of Artemia salina was evaluated. An increase in toxicity of carbophenothion was found following longer development of A. salina. The effect of pretreatment with the nonselective muscarinic antagonist atropine, the two reversible acetylcholinesterase-inhibitors physostigmine and pyridostigmine, and the cholinesterase-reactivating oxime 2-pyridine aldoxime methochloride (2-PAM) on carbophenothion-induced lethality in 24-h-old A. salina was also investigated. The lethal action of carbophenothion was completely prevented by pretreatment of A. salina with 2-PAM. Atropine and pyridostigmine afforded a maximal protection of approximately 87% and 72%, respectively, compared to control values. In contrast, physostigmine was ineffective. The inhibitory effects of combinations of 10(-5) M atropine with physostigmine, pyridostigmine, or 2-PAM were greater than those elicited by either drug alone, with the maximum protection afforded being 92.58%, 100%, and 100%, respectively. In the presence of 10(-7) M atropine, neither pyridostigmine nor 2-PAM provided additional inhibition of the lethality compared to that with either drug alone, whereas the protection afforded by 10(-7) M atropine plus physostigmine increased as the concentration of carbamate increased (up to 10(-3) M). Pretreatment with pyridostigmine or physostigmine plus 2-PAM (10(-6) M) slightly enhanced the maximal inhibition of carbophenothion lethality compared to that with either drug alone. It is suggested that the most active combined pretreatment studied here was physostigmine plus atropine.

Animals↗