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Eriksson O, Wills JM, Wallace D. Electronic, quasiharmonic, and anharmonic entropies of transition metals. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:5221-5228. [PMID: 10004297 DOI: 10.1103/physrevb.46.5221] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Abstract
The Lunatic Reception House at Darlinghurst operated between 1868 and 1961. Established to remove the stigma of criminality from the care of the insane, it operated as an observation ward and was for most of its time the sole portal of entry into metropolitan psychiatric hospitals in Sydney. An account of its inception and notable aspects of its history, with particular reference to lunacy legislation, is presented.
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Rosenfeld JV, Wallace D, Klug GL, Danks A. Transnasal stereotactic biopsy of a clivus tumor. Technical note. J Neurosurg 1992; 76:878-9. [PMID: 1304716 DOI: 10.3171/jns.1992.76.5.0878] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Computerized tomography-guided transnasal stereotactic tissue diagnosis of a lytic lesion in the clivus was performed successfully using the Cosman-Roberts-Wells frame, thus avoiding a major craniotomy. The authors recommend stereotaxis as the preferred technique for biopsy in this region.
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Lloyd-Puryear M, Wallace D, Baldwin T, Hollis DG. Meningitis caused by Psychrobacter immobilis in an infant. J Clin Microbiol 1991; 29:2041-2. [PMID: 1774332 PMCID: PMC270256 DOI: 10.1128/jcm.29.9.2041-2042.1991] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Psychrobacter immobilis was isolated from the cerebrospinal fluid (CSF) and blood of a 2-day-old infant who appeared well except for a fever and a full anterior fontanelle. The infant was treated with antibiotics intravenously. After 48 h, he became afebrile and CSF and blood cultures were negative; he was then discharged. After 96 h of incubation, CSF and blood cultures yielded a gram-negative organism, P. immobilis. The child was readmitted to the hospital, and the same organism was again isolated from his blood and CSF.
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Shewring DJ, Wallace D, Healy CM. Skin avulsion during manipulation of fractures. BMJ (CLINICAL RESEARCH ED.) 1991; 303:513-4. [PMID: 1912865 PMCID: PMC1670813 DOI: 10.1136/bmj.303.6801.513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Brownsill R, Wallace D, Taylor A, Campbell B. Study of human urinary metabolism of fenfluramine using gas chromatography-mass spectrometry. JOURNAL OF CHROMATOGRAPHY 1991; 562:267-77. [PMID: 2026697 DOI: 10.1016/0378-4347(91)80584-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The metabolism of (+/-)fenfluramine, 1-(m-trifluoromethylphenyl)-2-N-ethylpropane, an anoretic agent, was investigated in humans. The analysis method was based on the use of ion-exchange resin extraction, solid-phase purification on the Bond Elut1M C8 cartridge, gradient elution high-performance liquid chromatography, enzymic hydrolysis of conjugates, further purification by Bond Elut C8 cartridge, derivatisation and capillary column gas chromatography-mass spectrometry (GC-MS). After administration of a 1 mg kg-1 oral dose, four metabolites plus unchanged fenfluramine were recovered in the 0-24 h urine from human volunteers and characterised by GC-MS. In the conjugated form, fenfluramine, norfenfluramine and m-trifluoromethylhippuric acid were detected by GC-MS. In the aglycone form, the major metabolite, 1-(m-trifluoromethylphenyl)-1,2-propane diol (fenfluramine diol), was monitored using GC-MS. The mass spectral characteristics of the m-trifluoromethylhippuric acid methyl ester, 1-(m-trifluoromethylphenyl)-1,2-propane ditrifluoracetate derivatives and the norfenfluramine and fenfluramine free base obtained under electron-impact ionization are presented. The metabolism of fenfluramine is discussed including a metabolic pathway in man accounting for the formation of its biotransformation products.
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O'Brien TR, Polon C, Schable CA, VanDevanter N, Rayfield MA, Wallace D, Stuart A, Holmberg SD. HIV-2 infection in an American. AIDS 1991; 5:85-8. [PMID: 2059365 DOI: 10.1097/00002030-199101000-00012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
HIV-2 is endemic in West Africa but rare elsewhere. In the USA there have been 18 reported cases of HIV-2 infection; most identified people have been West Africans. We recently diagnosed the first case of HIV-2 infection in a native-born US citizen, a woman whose serum was found to be reactive to anti-HIV-1 enzyme immunoassay (EIA) when she attempted to donate blood in 1986. Although both HIV-1- and HIV-2-specific EIAs were reactive, the anti-HIV-2 Western blot (WB) was positive, while the anti-HIV-1 WB was positive or indeterminate on different occasions. Synthetic peptide testing was reactive for HIV-2 but not HIV-1. HIV-2 DNA was detected using the polymerase chain reaction procedure. Although she had travelled to West Africa, it is unclear how she became infected with HIV-2.
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Chong P, Matzner WL, Yamiguchi D, Wallace D, Klinenberg JR, Jordan SC. Inhibition of protein-kinase C in peripheral blood mononuclear cells of patients with systemic lupus erythematosus: effect on spontaneous immunoglobulin production. Autoimmunity 1991; 10:227-31. [PMID: 1756225 DOI: 10.3109/08916939109001893] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Systemic Lupus Erythematosus (SLE) is a multisystem disease characterized by an increase in the spontaneous secretion of immunoglobulin (Ig) molecules, many of which are autoreactive. We have previously shown (Biochem & Biophys. Res. Comm. (1989) 161: 1319-1326) that normal human peripheral blood mononuclear cells (PBMCs) can be stimulated to secrete large quantities of Ig upon incubation with the protein kinase-C activator 1 oleoyl-2-acetyglycerol (OAG). Specific blockage of protein kinase C with the isoquinoline sulfonyl piperazine compound (H-7) inhibited the OAG-induced Ig production. In experiments reported here, PBMC of 5 patients with active SLE produced high levels of IgG spontaneously in culture. PBMC of 6 inactive SLE patients and 7 normal control subjects produced comparable low levels of IgG spontaneously. Pokeweed mitogen (PWM) stimulation of PBMC in inactive SLE and control groups, but not active SLE patients produced markedly enhanced IgG production. The lack of response to PWM stimulation in active SLE patients is likely due to inherent maximal stimulation of active SLE B-cells. In addition, we examined the ability of H-7 to inhibit both mitogen-stimulated (normal and inactive SLE) and spontaneous (active SLE) Ig production. In other experiments, we also examined the ability of the isoquinoline sulfonamide (HA-1004), a potent inhibitor of cAMP-dependent protein kinase to regulate mitogen stimulated and spontaneous Ig production in the patient groups indicated above. H-7 significantly inhibited PWM stimulated Ig production in normal (P less than 0.0001) and inactive SLE patients, (P less than 0.040) suppressing PWM stimulated levels to spontaneous levels.(ABSTRACT TRUNCATED AT 250 WORDS)
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Wallace D, Amiel D. 488 SUBCELLULAR RESPONSE OF THE ANTERIOR CRUCIATE LICAMENT (ACL) AND MEDIAL COLLATERAL LIGAMENT (MCL) TO INJURY. Med Sci Sports Exerc 1990. [DOI: 10.1249/00005768-199004000-00488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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211
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Wallace R, Wallace D. Origins of public health collapse in New York City: the dynamics of planned shrinkage, contagious urban decay and social disintegration. BULLETIN OF THE NEW YORK ACADEMY OF MEDICINE 1990; 66:391-434. [PMID: 2257377 PMCID: PMC1809782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Sullivan LP, Grantham JA, Rome L, Wallace D, Grantham JJ. Fluorescein transport in isolated proximal tubules in vitro: epifluorometric analysis. THE AMERICAN JOURNAL OF PHYSIOLOGY 1990; 258:F46-51. [PMID: 2301596 DOI: 10.1152/ajprenal.1990.258.1.f46] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An epifluorometric method was used to quantify the bidirectional fluxes of fluorescein across the basolateral surfaces of nonperfused rabbit tubule segments in vitro. Proximal S2 segments, but not cortical collecting tubules or cortical thick ascending limbs, accumulated fluorescein to levels in cytoplasm over 100-fold greater than in the external medium. The rate of intracellular fluorescein accumulation was dependent on the concentration of the ligand in the external bath. The apparent Km was 10 microM and the Vmax was 623 x 10(-6) mol.min-1.l-1. Probenecid and ouabain inhibited fluorescein accumulation. We conclude that fluorescein is transported into the cytoplasm of proximal tubules by basolateral mechanisms that share features in common with the classical organic anion system. This fluorescent compound offers some unique advantages for the study of the organic anion transport system in intact cells.
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Abstract
During the 1970s, New York city experienced an epidemic of housing destruction by contagious fire and building abandonment. This epidemic was triggered by reductions in municipal services, especially fire control, in the poor areas of high population density and aging housing. The rapid loss of low rent housing led to a wave of forced internal migration of the poor within the city and overcrowding of areas adjacent to the burned out ones. The spread of overcrowding spread the high fire incidence. The massive upheaval resulted in destruction of social networks and in degraded living conditions. Public health, as measured by many indices such as disease incidence, substance abuse incidence, infant mortality, and incidence of homicide, deteriorated. This deterioration caused increased demand for hospital health care, especially emergency service. The data on average stay length in the poorest areas in comparison with wealthier areas hints that the overloading of the voluntary hospitals in the poorest areas has caused care rationing and greater inequality in access to care.
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Ings RM, Gray AJ, Taylor AR, Gordon BH, Breen M, Hiley M, Brownsill R, Marchant N, Richards R, Wallace D. Disposition, pharmacokinetics, and metabolism of 14C-fotemustine in cancer patients. Eur J Cancer 1990; 26:838-42. [PMID: 2145908 DOI: 10.1016/0277-5379(90)90166-q] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The pharmacokinetics and metabolism of intravenously infused 14C-fotemustine (about 100 mg/m2) were examined in 2 cancer patients. Plasma levels of radioactivity increased to a maximum of 4.1 and 5.5 micrograms equivalents per g when the infusion stopped then declined triexponentially with mean half-lives of about 1/2, 10 and 80 h for the initial, mid and terminal phases, respectively. Plasma levels of intact drug were lower, with maximum levels of 1.1 and 2.8 micrograms/ml, and declined monophasically with a half-life of about 24 min. Plasma clearance was high (1426 and 764 ml/min) with the volume of distribution based on areas of 47.7 and 26.4 l. Most of the radioactivity was eliminated in urine (50.1 and 61.3%) over 7 days with smaller amounts in the feces (6.8 and 0.3%) and only minimal quantities (under 0.1%) as expired carbon dioxide. Metabolites of fotemustine were identified as chloroethanol and N-nitroso-1-imidazolone-ethyl-diethylphosphonate in plasma and as 1-hydantoin-ethyl-diethyl-phosphonate and acetic acid in urine.
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Wallace D, Ivey JD. The bifocal clinical nursing model: description and application to the patient receiving thrombolytic or anticoagulant therapy. J Cardiovasc Nurs 1989; 4:33-45. [PMID: 2600614 DOI: 10.1097/00005082-198911000-00006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Carpenito's bifocal clinical nursing model enables the clinician to address the spectrum of clinical possibilities and problems associated with patients receiving thrombolytic and anticoagulant agents. Through correct application of nursing diagnoses, collaborative problems, and referrals, a global and multidisciplinary approach to patient care is achieved.
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Imagawa W, Bandyopadhyay GK, Wallace D, Nandi S. Phospholipids containing polyunsaturated fatty acyl groups are mitogenic for normal mouse mammary epithelial cells in serum-free primary cell culture. Proc Natl Acad Sci U S A 1989; 86:4122-6. [PMID: 2471196 PMCID: PMC287401 DOI: 10.1073/pnas.86.11.4122] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Epithelial cells obtained by collagenase digestion of mammary glands from virgin BALB/c mice were cultured in collagen gels in serum-free basal medium containing insulin (10 micrograms/ml), to which lipids or growth factors were added. Synthetic phospholipids were added as liposomes. Dilinoleoyl phosphatidic acid or phosphatidylserine or epidermal growth factor stimulated multifold growth. The optimum mitogenic effect of the phospholipids was dependent upon the presence of a polyunsaturated fatty acid esterified to the sn-2 position of the glycerol moiety. Dilinoleoyl phosphatidylcholine also stimulated growth but was generally less stimulatory than phosphatidylserine or phosphatidic acid, and phosphatidylethanolamine did not stimulate growth. Studies using phospholipids radiolabeled in either the sn-2 fatty acyl group or the glycerol backbone showed that the relative effect of phospholipids on growth did not correlate directly with the extent of their incorporation into cellular lipid, indicating that phospholipid turnover was the more important determinant for mitogenesis. Analysis of phosphatidic acid-stimulated growth suggested that both cAMP-dependent and cAMP-independent pathways were involved. Thus, mitogenic phospholipids stimulate proliferation by activating (directly or indirectly) multiple growth-regulatory pathways in mammary epithelial cells.
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Wallace D, Herndon J. A systems approach to controlling unofficial inventory. JOURNAL OF HEALTHCARE MATERIEL MANAGEMENT 1989; 7:52-4. [PMID: 10292608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Bhavnani BR, Woolever CA, Wallace D, Pan CC. Metabolism of [3H]equilin-[35S]sulfate and [3H]equilin sulfate after oral and intravenous administration in normal postmenopausal women and men. J Clin Endocrinol Metab 1989; 68:757-65. [PMID: 2921309 DOI: 10.1210/jcem-68-4-757] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The absorption of equilin sulfate and equilin from the gastrointestinal tract was determined in normal men after the ingestion of [3H]equilin-[35S]sulfate or a mixture of [3H]equilin and equilin-[35S]sulfate, while the metabolism of equilin sulfate was investigated after iv administration of [3H]equilin sulfate to postmenopausal women. After the oral administration of [3H]equilin-[35S]sulfate, equilin sulfate containing both 3H and 35S was isolated from plasma; however, only in the first sample taken at 10 min was the 3H/35S ratio the same as that of the [3H]equilin-[35S]sulfate ingested. The 3H/35S ratio then increased, and by 12 h only traces of equilin-[35S]sulfate were detectable. Similarly, after the ingestion of [3H]equilin and equilin-[35S]sulfate, [3H]equilin-[35S]sulfate was isolated from plasma. The 3H/35S ratio was at all time points greater than the 3H/35S ratio of the ingested mixture. Analysis of urine indicated that over 98% of 35S was not associated with any steroid and was most likely inorganic sulfate. After iv administration of [3H] equilin sulfate to postmenopausal women, equilin, equilenin, 17 beta-dihydroequilin, and 17 beta-dihydroequilenin were isolated from the urine. These results indicate that 1) some of the orally administered equilin sulfate was absorbed from the gut without prior hydrolysis, 2) some equilin sulfate was hydrolyzed in the gut before absorption; 3) equilin was absorbed more efficiently than equilin sulfate; 4) equilin absorbed was readily sulfated and circulated in this form; and 5) equilin sulfate was extensively metabolized, and the metabolites were excreted in the urine mainly conjugated with glucuronic acid.
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Huzoor-Akbar, Chen NY, Fossen DV, Wallace D. Increased vascular contractile sensitivity to serotonin in spontaneously hypertensive rats is linked with increased turnover of phosphoinositide. Life Sci 1989; 45:577-83. [PMID: 2549317 DOI: 10.1016/0024-3205(89)90042-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study was conducted to determine if increased vascular contractile sensitivity to serotonin in spontaneously hypertensive (SHR) rats is linked with increased phosphoinositide turnover. Aortic and mesenteric artery rings from SHR exhibited 6.2- and 5.0-fold greater contractile sensitivity to serotonin than the aortic and mesenteric artery rings from normotensive Wistar-Kyoto (WKY) rats. Serotonin-induced turnover of phosphoinositide was measured by quantifying the accumulation of [3H] inositol labeled inositol monophosphate (IP), inositol bisphosphate (IP2) and inositol trisphosphate (IP3). Serotonin (3, 30, 200 microM) induced significantly greater accumulation of IP in SHR (279%, 590%, 895%) than in WKY (24%, 127%, 328%) aortic rings. Similarly, 3, 30 and 200 microM serotonin induced significantly greater accumulation of IP2 (118%, 241%, 451%) and IP3 (90%, 100%, 247%) in SHR than the accumulation of IP2 (15%, 58%, 122%) and IP3 (19%, 27%, 73%) in WKY aortic rings. Based on these data it is suggested that the greater vascular sensitivity to serotonin in SHR, at least in part, is attributable to increased turnover of phosphoinositide.
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Koshy M, Burd L, Wallace D, Moawad A, Baron J. Prophylactic red-cell transfusions in pregnant patients with sickle cell disease. A randomized cooperative study. N Engl J Med 1988; 319:1447-52. [PMID: 3054555 DOI: 10.1056/nejm198812013192204] [Citation(s) in RCA: 193] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Prophylactic blood transfusion has come to be regarded as necessary in the treatment of patients with sickle cell disease during pregnancy. Because of the risks associated with blood products and reports of successful outcomes without the use of blood transfusion, we conducted a prospective randomized controlled study of this issue. Seventy-two pregnant patients with sickle cell anemia were randomly assigned to one of two treatment groups: 36 received prophylactic transfusions of frozen red cells, and 36 received red-cell transfusions only for medical or obstetric emergencies. Twenty-eight patients with sickle cell anemia who did not qualify for randomization (mainly because they had other medical disorders), 66 with sickle cell-hemoglobin C disease, and 23 with sickle cell-beta-thalassemia were also followed and received transfusions only for emergencies. There was no significant difference in perinatal outcome between the offspring of mothers with sickle cell disease who were assigned to treatment with prophylactic transfusions and those who were not (15 vs. 5 percent). The occurrence of a perinatal death in a previous pregnancy and the presence of twins in the present pregnancy were two major risk factors for an unfavorable outcome; when they were present, perinatal mortality was 50 percent. Perinatal mortality was somewhat higher in the two groups that were randomized than in the three groups that were not. Prophylactic transfusion significantly reduced the incidence of painful crises of sickle cell disease (P less than 0.01) and substantially reduced the cumulative incidence of other complications of this disorder (P = 0.07). Other medical and obstetric complications occurred with nearly equal frequency in the two randomized groups. Increases in costs, the number of hospitalizations, and the risk of alloimmunization were disadvantages of prophylactic transfusion. We conclude that the omission of prophylactic red-cell transfusion will not harm pregnant patients with sickle cell disease or their offspring.
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Gerson A, Johnson A, Wallace D, Bottalico J, Weiner S, Bolognese R. Umbilical arterial systolic/diastolic values in normal twin gestation. Obstet Gynecol 1988; 72:205-8. [PMID: 3292978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Linear regression analysis was used to describe the relationship of umbilical arterial systolic/diastolic values to gestational age in 65 twin gestations. This relationship (y = 6.18 - 0.11x) was then compared with a previously described regression for singleton pregnancies using a multiple regression model. This comparison revealed that the relationship between the systolic/diastolic ratio and gestational age is the same in singleton and twin gestations.
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Imagawa W, Bandyopadhyay GK, Wallace D, Nandi S. Growth stimulation by PGE2 and EGF activates cyclic AMP-dependent and -independent pathways in primary cultures of mouse mammary epithelial cells. J Cell Physiol 1988; 135:509-15. [PMID: 2456289 DOI: 10.1002/jcp.1041350320] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mammary epithelial cells from virgin Balb/c mice were isolated by collagenase digestion and cultured within collagen gels in serum-free basal medium containing insulin (10 micrograms/ml). Previous work has shown that linoleate or its metabolite, prostaglandin E2 (PGE2), stimulate the growth of these cells only in the presence of a growth stimulant such as epidermal growth factor (EGF). Since PGE2 can stimulate cyclic AMP (cAMP) production, the role of cAMP in linoleate and EGF-stimulated growth was examined. The cAMP phosphodiesterase inhibitor, IBMX (0.1 mM), was found to augment growth when cells were cultured in the presence of both EGF and linoleate or PGE2, but not either factor alone. These results indicated that EGF does not stimulate proliferation via cyclic AMP mediated events but could synergize with cAMP events if cAMP levels were elevated by PGE2. When assayed in cells plated on top of collagen-coated culture dishes, cellular cyclic AMP levels were stimulated by PGE2, but only marginally by EGF. Although the stimulation of endogenous cAMP by PGE2 and IBMX was insufficient to stimulate growth in the absence of EGF, exogenous dibutyryl-cAMP (greater than 100 micrograms/ml) was able to do so showing that a sustained, and high level of cAMP (greater than 100 micrograms/ml) could stimulate growth in insulin-containing basal medium. EGF was capable of enhancing the cellular sensitivity to dibutyryl-cAMP but the converse was not observed. cAMP stimulation of growth was dependent upon a superphysiological concentration of insulin (10 micrograms/ml) or a physiological concentration of somatomedin-C. These results indicate that the proliferation of mouse mammary epithelial cells can be stimulated separately or in synergism by cAMP-dependent or -independent events.
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Bhavnani BR, Enhorning G, Ekelund L, Wallace D, Pan CC. Maternal diabetes and its effect on biochemical and functional development of rabbit fetal lung. Biochem Cell Biol 1988; 66:396-404. [PMID: 3408584 DOI: 10.1139/o88-048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The effect of maternal diabetes on functional and biochemical maturation of the fetal lung was studied in a rabbit model. Pregnancy was initiated only after diabetes had been established. Both the pregnant doe and its fetuses were hyperglycemic. For comparison, the fetal heart and liver were also studied. In the diabetic group, the DNA content was lower in the fetal heart and lung while the protein content was higher in all three tissues. The glycogen levels were higher only in the fetal lung. Glycogen synthase was higher in the fetal lung and heart while phosphorylase activity was higher in all three tissues from the diabetic group. The activities of key enzymes involved in glycolysis were not affected. No difference was observed in the concentration of total phospholipids or in the ability of the airway fluid to reduce surface tension. In contrast, fetal lungs from diabetic does did not expand as well as the controls and retained less air on deflation. These findings suggest that the utilization of glycogen in fetal lungs from the diabetic does was not complete and that the increased incidence of respiratory distress in infants of diabetic mothers may not be due to a lack of surfactant.
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Anwer K, Wallace D, Romstedt K, Huzoor-Akbar. Human platelet activation by bacterial phospholipase C: mechanism of inhibition by flurazepam. Thromb Res 1988; 49:225-39. [PMID: 2896397 DOI: 10.1016/0049-3848(88)90216-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have shown earlier that phospholipase C (PLC) from Clostridium perfringens causes platelet activation possibly by inducing turnover of phosphoinositides and phosphorylation of a 47,000 Dalton protein (P47). Moreover, only 15 microM and 11 microM flurazepam inhibits PLC-induced platelet aggregation and serotonin secretion by 50% respectively. This study was conducted to better understand the mechanism of platelet activation by PLC and its inhibition by flurazepam. Incubation of (14C)-arachidonic acid labelled platelets with PLC produced diacylglycerol in a time- and concentration-dependent manner. Flurazepam did not inhibit diacylglycerol production by PLC. Paranitrophenolphosphorylcholine and prostaglandin E1 inhibited diacylglycerol production by 75% and 20% respectively. In a platelet-free system PLC hydrolyzed 14C-choline-phosphatidylcholine (14C-PC) in a time- and calcium ions-dependent manner. Flurazepam had no effect on PLC-induced hydrolysis of 14C-PC. Platelet cytosolic fraction (PCF), containing phosphatidylinositol-specific PLC (PI-PLC), hydrolyzed (3H-inositol)-phosphatidylinositol (3H-PI) in a platelet-free system. Flurazepam did not inhibit hydrolysis of 3H-PI by PCF. Phospholipase C caused phosphorylation of P47 in 32P-labelled platelets. Flurazepam did not block phosphorylation of P47 in the first three minutes and had very little inhibitory effect by five minutes. However, flurazepam completely blocked phosphorylation of P47 by seven minutes. Platelet aggregation induced by ionomycin, a calcium ionophore, was completely inhibited by 100 microM flurazepam whereas platelet aggregation induced by 12-O-Tetradecanoylphorbol-13-acetate (TPA), which mimics the action of diacylglycerol, was partially inhibited by 300 microM flurazepam. These findings suggest that PLC induced platelet activation depends, at least in part, on diacylglycerol production and phosphorylation of P47. These data also suggest that flurazepam does not inhibit PLC-induced platelet activation by inhibiting: (a) the production of diacylglycerol from phosphatidylcholine; and (b) the action of PI-PLC on phosphatidylinositol. The ability of flurazepam to inhibit ionomycin-induced platelet aggregation indicates that flurazepam is able to block platelet activation by inhibiting the increase in free cytosolic calcium ions in platelets or by inhibiting a step subsequent to the rise in intraplatelet calcium ions.
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Yu SH, Wallace D, Bhavnani B, Enhorning G, Harding PG, Possmayer F. Effect of reconstituted pulmonary surfactant containing the 6000-dalton hydrophobic protein on lung compliance of prematurely delivered rabbit fetuses. Pediatr Res 1988; 23:23-30. [PMID: 3340440 DOI: 10.1203/00006450-198801000-00006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Chloroform:methanol extracts of bovine pulmonary surfactant contain small hydrophobic proteins, designated surfactant-associated apoproteins 6,000 (SAP-6), but do not contain the major surfactant-associated 35,000-dalton glycoprotein, designated SAP-35. Examination of lipid extract surfactant on sodium dodecylsulfate-polyacrylamide gel electrophoresis revealed hydrophobic proteins with apparent molecular masses of 15,000, 7,000, and 3,5000 daltons prior to reduction. After reduction, the 15,000-dalton species largely disappeared and was replaced by a 5,000-dalton species. In addition, the 7000- and 3500-dalton species exhibited a slightly enhanced mobility. Amino acid analysis demonstrated that SAP-6 possesses a more highly hydrophobic profile than SAP-35. Combining the protein-containing fractions from silicic acid chromatography of lipid extract with synthetic dipalmitoylphosphatidylcholine produced a reconstituted surfactant preparation which was just as active as lipid extract surfactant on a pulsating bubble surfactometer. The reconstituted surfactant contained SAP-6 but not SAP-35. Pressure-volume studies revealed that, at the optimal dose, reconstituted surfactant containing half the SAP-6 concentration of lipid extract exhibited similar effectiveness to lipid extract surfactant in promoting lung expansion with prematurely delivered rabbit fetuses of 27 days gestation. Reconstituted surfactant with an identical SAP-6 protein concentration as lipid extract possessed the same biological properties as the preparation with 1% SAP-6 protein. These studies support the view that an artificial surfactant composed of synthetic or semisynthetic lipids plus human SAP-6 produced via biotechnology could be useful for prevention and/or treatment of the neonatal respiratory distress syndrome.
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