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Hassoun PM, Yu FS, Zulueta JJ, White AC, Lanzillo JJ. Effect of nitric oxide and cell redox status on the regulation of endothelial cell xanthine dehydrogenase. THE AMERICAN JOURNAL OF PHYSIOLOGY 1995; 268:L809-17. [PMID: 7762682 DOI: 10.1152/ajplung.1995.268.5.l809] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have previously reported that endothelial cell (EC) xanthine dehydrogenase/xanthine oxidase (XD/XO) activity correlates inversely with the O2 tension to which the cells are exposed. Whether this effect is related to the production of reactive O2 species is unclear. We exposed bovine pulmonary artery EC to various conditions that altered the redox status of the cells: 1) hypoxia (3% O2) and normoxia (20% O2); 2) menadione (MEN), known to generate O2 radicals; 3) catalase (CAT) and reduced glutathione (GSH), which detoxify H2O2; and 4) various NO-generating systems. Changes in intracellular XO and XO + XD activities were correlated with rates of extracellular H2O2 release from the same cells. Conditions that decreased extracellular H2O2 release (hypoxia, CAT, and GSH) produced significant and parallel increases in intracellular XO and XO + XD activities in a time-dependent fashion. MEN treatment increased extracellular release of H2O2 and subsequently reduced intracellular XO and XO + XD activities. NO-generating agents did not change extracellular release of H2O2 but significantly reduced XO and XO + XD activities. The latter effect was prevented by reduced hemoglobin. Scavengers of hydroxyl radicals reversed the inhibition of XO and XO + XD activities produced by MEN but not that produced by NO. While NO significantly inhibited XD/XO activity from rat epididymal fat pad, it did not affect XD/XO mRNA expression in these cells. We conclude that intracellular XD/XO activity is sensitive to changes in oxidant-generating and protective systems. Inhibition of XD/XO activity by NO may be mediated through direct binding of NO to the enzyme iron-sulfur moiety or to its sulfhydryl groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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Kennedy NM, Whittington RM, White AC. Suicide by self-strangulation whilst under observation. MEDICINE, SCIENCE, AND THE LAW 1995; 35:174-177. [PMID: 7776869 DOI: 10.1177/002580249503500213] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Two cases are reported of individuals who committed suicide after they had been identified as being acutely at risk of killing themselves. Self-strangulation by a ligature fashioned from the subjects' clothes was the mechanism of suicide in both cases. One death occurred in a police station and the other on an acute psychiatric ward. These cases highlight the need for those formulating policies concerning the supervision of the suicidal individual to pay attention to the minutiae of detail. In particular, a case is made for those at risk of suicide to be prevented from sleeping with their head covered by blankets.
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Goodgame RW, Kimball K, Ou CN, White AC, Genta RM, Lifschitz CH, Chappell CL. Intestinal function and injury in acquired immunodeficiency syndrome-related cryptosporidiosis. Gastroenterology 1995; 108:1075-82. [PMID: 7698574 DOI: 10.1016/0016-5085(95)90205-8] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND/AIMS The pathogenesis of the diarrhea in acquired immunodeficiency syndrome (AIDS)-related cryptosporidiosis is not known. The hypothesis of this study was that the intestinal dysfunction and injury are related to the number of organisms infecting the intestinal mucosa. The aim of this study was to study the influence of intensity of infection on intestinal function and injury in AIDS-related cryptosporidiosis. METHODS In 16 patients with AIDS with intestinal Cryptosporidium infection, the intensity of infection was quantified by counting the total number of fecal oocysts excreted in 24 hours and by determining the percent of duodenal epithelium covered by organisms. Intestinal function was assessed by vitamin B12 absorption and serum D-xylose test. Intestinal injury was assessed by morphology of duodenal mucosa, differential urinary excretion of lactulose and mannitol, and fecal alpha 1-antitrypsin clearance. Measurements were repeated after treatment with paromomycin. RESULTS Vitamin B12 and D-xylose absorption negatively correlated with intensity of infection. Villus atrophy occurred only in patients with oocyst excretion of > 10(8) oocyst/24 hours. Lactulose/mannitol urinary excretion ratio showed a positive correlation with intensity of infection. Intestinal function and injury improved in patients whose oocyst counts were reduced by treatment with paromomycin. CONCLUSIONS Cryptosporidium infection in patients with AIDS causes malabsorption and intestinal injury in proportion to the number of organisms infecting the intestine.
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Hermsmeyer K, White AC, Triggle DJ. Decreased dihydropyridine receptor number in hypertensive rat vascular muscle cells. Hypertension 1995; 25:731-4. [PMID: 7721424 DOI: 10.1161/01.hyp.25.4.731] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To further investigate the altered function of Ca2+ channels in vascular muscle cells in hypertension, a novel fluorescently labeled dihydropyridine was used with ultrahigh-sensitivity photometry to study dihydropyridine binding sites on the surface membrane of living vascular muscle cells from stroke-prone spontaneously hypertensive rats and their normotensive controls. Fluorescent nitrobenzoxadiazol-6-dihydropyridine in concentrations of 1 to 100 nmol/L bound specifically to vascular muscle cells' Ca2+ channels, and was displaced by the unlabeled dihydropyridine analogue or nisoldipine (10 mumol/L). Stroke-prone spontaneously hypertensive rat vascular muscle cells showed significantly decreased binding of nitrobenzoxadiazol-6-dihydropyridine compared with normotensive National Institutes of Health rats. Decreased binding of dihydropyridine by vascular muscle cells from stroke-prone spontaneously hypertensive rats (cells that in other studies show increased Ca2+ channel function) indicates a change in channel regulation that is possibly due to a deficiency in the inactivation mechanism, consistent with our earlier electrophysiological studies reporting deficiencies in Ca(2+)-dependent inactivation in genetic hypertension. These data demonstrate decreased numbers of localized sites of dihydropyridine binding on the sarcolemma of living vascular muscle cells, and support the hypothesis that Ca2+ channel alterations may significantly contribute to the molecular etiology of genetic hypertension.
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Coughlin RT, Fattom A, Chu C, White AC, Winston S. Adjuvant activity of QS-21 for experimental E. coli 018 polysaccharide vaccines. Vaccine 1995; 13:17-21. [PMID: 7762272 DOI: 10.1016/0264-410x(95)80005-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Three types of experimental vaccines containing O-side-chain polysaccharide from the enterotoxigenic strain Escherichia coli 018 were evaluated. The immunogenicity of free O-polysaccharide (PS), a polysaccharide-diphtheria toxoid conjugate (PS-conj), and detoxified lipopolysaccharide (dLPS) was tested in female ICR mice, either alone or in combination with QS-21, a purified saponin adjuvant derived from the bark of the tree Quillaja saponaria Molina. Both the number of individual mice responding and the titres of O-polysaccharide specific antibodies in pools of sera were increased by the addition of QS-21. The immune response to both O-specific polysaccharide and carrier was primarily IgM and IgG1. The addition of QS-21 not only increased the level of IgG1, but also had a significant adjuvant effect on antigen-specific IgG2a, IgG2b and IgG3.
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Hume SP, Ashworth S, Opacka-Juffry J, Ahier RG, Lammertsma AA, Pike VW, Cliffe IA, Fletcher A, White AC. Evaluation of [O-methyl-3H]WAY-100635 as an in vivo radioligand for 5-HT1A receptors in rat brain. Eur J Pharmacol 1994; 271:515-23. [PMID: 7705452 DOI: 10.1016/0014-2999(94)90813-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
N-(2-(4-(2-Methoxyphenyl)-1-piperazinyl)ethyl)-N-(2- pyridyl)cyclohexanecarboxamide trihydrochloride (WAY-100635) is a new, potent and selective 5-HT1A receptor antagonist. We have evaluated radiolabelled WAY-100635 as a prospective radioligand for positron emission tomography (PET) by studying biodistribution in rat ex vivo. After intravenous injection, [O-methyl-3H]WAY-100635 cleared rapidly from plasma but was retained in brain. Specific binding was quantified from kinetic studies, using a reference-tissue compartment model, fitting for binding potential (k3/k4). The regional variation in binding potential correlated with the known distribution of 5-HT1A receptors. Saturation studies gave Bmax values in vivo that were consistent with those reported in vitro. At 60 min after injection, the ratio of radioactivity in 5-HT1A receptor-rich regions (e.g. septum, entorhinal cortex and hippocampus) to that in cerebellum reached approximately 16. Pre-dosing the rats with WAY-100635 (2 mg/kg) reduced this ratio to one, whereas similar pre-dosing with citalopram (5-HT uptake site inhibitor), prazosin (alpha 1A-adrenoceptor antagonist) or idazoxan (alpha 2-adrenoceptor antagonist) caused little or no reduction. Substantial (77%) blockade of [3H]WAY-100635 binding was achieved with the 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), and the partial agonists, ipsapirone and buspirone. Thus, the properties of WAY-100635 are such that, when labelled with carbon-11, it could provide a radioligand suitable for clinical and pharmacological investigations of central 5-HT1A receptors in man using PET.
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Shergill JK, Butler CS, White AC, Cammack R, Mason JR. EPR, ENDOR and ESEEM studies on recombinant benzene dioxygenase. Biochem Soc Trans 1994; 22:288S. [PMID: 7821547 DOI: 10.1042/bst022288s] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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White AC, Chappell CL, Hayat CS, Kimball KT, Flanigan TP, Goodgame RW. Paromomycin for cryptosporidiosis in AIDS: a prospective, double-blind trial. J Infect Dis 1994; 170:419-24. [PMID: 8035029 DOI: 10.1093/infdis/170.2.419] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
To test the effects of paromomycin, 10 patients with AIDS and cryptosporidiosis were randomized to paromomycin or placebo in a double-blind trial. After 14 days, patients were switched to the other treatment for 14 additional days. Measures included the number and character of each stool and weekly 24-h stool specimens for weight and oocyst excretion. During the paromomycin treatment phase, oocyst excretion decreased from 314 x 10(6) to 109 x 10(6)24 h (P < .02). Oocyst excretion increased for the 4 patients initially on placebo compared to a median decrease of 128 x 10(6)/24 h for the 6 initially treated with drug (P < .02). Stool frequency also decreased more in those treated with drug (3.6 fewer vs. 1.25 fewer/24 h, P < .05). Trends favored drug over placebo for stool weight, stool character, and Karnofsky score. Paromomycin treatment resulted in improvement in both clinical and parasitologic parameters in cryptosporidiosis in AIDS.
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Moore TA, Tomayko JF, Wierman AM, Rensimer ER, White AC. Imported malaria in the 1990s. A report of 59 cases from Houston, Tex. ARCHIVES OF FAMILY MEDICINE 1994; 3:130-6. [PMID: 7994434 DOI: 10.1001/archfami.3.2.130] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To determine the frequency, the clinical features, and the response to therapy of imported malaria that was diagnosed in the 1990s in a major North American city. METHOD A retrospective case series from Houston, Tex, of 59 cases of imported malaria presenting between January 1990 and April 1993. RESULTS Malaria was diagnosed in 59 patients, consisting of 12 cases among patients who had acquired the infection while they were living in endemic areas prior to immigration to the United States, 32 cases among US residents who were originally from endemic areas, and 15 cases among patients originally from North America or Europe. Only 12 patients had received malarial prophylaxis: eight with chloroquine, one with chloroquine and chloroguanide (proguanil), two with chloroquine and primaquine, and one with mefloquine taken intermittently. Eight presented with Plasmodium falciparum infection after receiving chloroquine, and one, after receiving chloroquine and chloroguanide. Two presented with malaria caused by Plasmodium vivax despite receiving chloroquine and primaquine as prophylaxis. In 25 cases, malaria was not considered as an initial diagnosis. Five patients presented with severe disease (three with severe hemolysis, two each with cerebral malaria and renal failure, and one with adult respiratory distress syndrome). Four of the five had initially received a misdiagnosis. Two patients died despite treatment with intravenous quinidine and exchange transfusions. Two patients with P vivax infection had multiple relapses despite courses of chloroquine and primaquine. Six patients were pregnant (including one with a fatal case), one congenital infection was identified. Six patients had not traveled outside of the United States in over 1 year. CONCLUSION Imported malaria occurs frequently and usually results from the failure to use appropriate prophylaxis. Delayed diagnosis and misdiagnosis are common. Severe disease and fatal cases continue to be seen despite aggressive treatment. Drug resistance has continued to spread and now occurs with P vivax as well as P falciparum.
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MESH Headings
- Adult
- Aged
- Animals
- Antimalarials/therapeutic use
- Diagnosis, Differential
- Drug Resistance
- Emigration and Immigration
- Female
- Humans
- Malaria/diagnosis
- Malaria/epidemiology
- Malaria/therapy
- Malaria/transmission
- Malaria, Falciparum/diagnosis
- Malaria, Falciparum/epidemiology
- Malaria, Falciparum/therapy
- Malaria, Falciparum/transmission
- Malaria, Vivax/diagnosis
- Malaria, Vivax/epidemiology
- Malaria, Vivax/therapy
- Malaria, Vivax/transmission
- Male
- Plasmodium malariae
- Pregnancy
- Pregnancy Complications, Parasitic/diagnosis
- Pregnancy Complications, Parasitic/epidemiology
- Pregnancy Complications, Parasitic/therapy
- Retrospective Studies
- Texas/epidemiology
- Travel
- Treatment Outcome
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Shandera WX, White AC, Chen JC, Diaz P, Armstrong R. Neurocysticercosis in Houston, Texas. A report of 112 cases. Medicine (Baltimore) 1994; 73:37-52. [PMID: 8309361 DOI: 10.1097/00005792-199401000-00004] [Citation(s) in RCA: 139] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Neurocysticercosis (NCC) is a common disease among Hispanic immigrants to the American Southwest. The experience in this series suggests a higher incidence of disease than has been reported by public health personnel. Symptoms at presentation correlate with the anatomic site of disease. Parenchymal disease and inactive calcifications present primarily with seizures; ventricular disease with headaches and symptoms of acute hydrocephalus; and cisternal disease with basilar meningitis, hydrocephalus, or seizures from coexisting parenchymal disease. Current treatment regimens are suboptimal, although symptoms may resolve in the absence of therapy. Patients may not respond to a single course of praziquantel therapy. Procedures to divert cerebrospinal fluid are often needed and frequently require revision. We found an association between corticosteroid treatment and the need for repeat therapy with praziquantel, but controlled studies are needed to clarify the role of antiparasitic agents in all forms of neurocysticercosis.
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Genta RM, Chappell CL, White AC, Kimball KT, Goodgame RW. Duodenal morphology and intensity of infection in AIDS-related intestinal cryptosporidiosis. Gastroenterology 1993; 105:1769-75. [PMID: 8253352 DOI: 10.1016/0016-5085(93)91075-s] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND The pathogenesis of intestinal cryptosporidiosis is not known. Previous studies have shown that the intensity of infection varies between patients. The hypothesis of this study is that intestinal injury is related to the intensity of infection. METHODS The histological abnormalities associated with Cryptosporidium infection were evaluated in duodenal biopsy specimens from 18 patients with acquired immunodeficiency syndrome-associated cryptosporidiosis. The intensity of Cryptosporidium infection was assessed histologically in all patients as the percentage of mucosa covered by organisms and by quantitation of oocyst excretion in the stools of 14 patients. RESULTS Duodenal biopsy specimens from 13 patients (72%) showed normal villous architecture. In these patients, the inflammatory component of the lamina propria was either normal or moderately increased. This increase consisted mostly of lymphocytes and plasma cells. Five of 18 patients (28%) had flattening of the mucosa associated with a prominent neutrophilic infiltrate. The intensity of infection in patients with villous flattening as measured from biopsy specimens and stool was significantly higher than in those without flattening (92% vs. 12% mucosa occupied with organisms; 738 x 10(3) vs. 199 x 10(3) oocyst/mL stool) (P < 0.004 in both cases). CONCLUSIONS Most patients with intestinal Cryptosporidium infection had normal duodenal villous architecture. Severe duodenal morphological abnormalities, including flattening of the villi, were associated with high-intensity infections.
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Thannickal VJ, Hassoun PM, White AC, Fanburg BL. Enhanced rate of H2O2 release from bovine pulmonary artery endothelial cells induced by TGF-beta 1. THE AMERICAN JOURNAL OF PHYSIOLOGY 1993; 265:L622-6. [PMID: 8279578 DOI: 10.1152/ajplung.1993.265.6.l622] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have previously reported that transforming growth factor-beta 1 (TGF-beta 1) produces a "prooxidant" effect on cultured bovine pulmonary artery endothelial cells (BPAEC) [S. K. Das and B. L. Fanburg. Am. J. Physiol. 261 (Lung Cell. Mol. Physiol. 5): L249-L254, 1991]. This effect was found to be associated with a lowering of total cellular GSH (A.C. White, S. K. Das, and B.L. Fanburg. Am. J. Respir. Cell Mol. Biol. 6: 364-368, 1992). In this study, we demonstrate a twofold increase in the rate of extracellular H2O2 release from BPAEC after a 72-h exposure to TGF-beta 1 (2 ng/ml, added at times 0 and 48 h). Increasing and decreasing the levels of cellular GSH with diethylmaleate (DEM, 0.05 mM) and buthionine sulfoximine (BSO, 0.01 mM), respectively, did not affect the rate of TGF-beta 1-induced increase in H2O2 release when compared with the individual effects of these reagents on control cells. The addition of BSO (0.01 mM) to control cells failed to demonstrate an increase in the rate of H2O2 release, despite a more profound decrease in cellular GSH by these cells than detected in cells treated with TGF-beta 1 alone. Moreover, a single dose of TGF-beta 1 (2 ng/ml) induced a 63-85% increase in the rate of H2O2 release within 16 h of exposure, well before the previously demonstrated lowering of cellular GSH. These results indicate that the increase in H2O2 production by TGF-beta 1-stimulated BPAEC is associated with, but does not appear to be the result of, a lowering of cellular GSH. This study further suggests that the TGF-beta 1-induced H2O2 production occurs at a site inaccessible to detoxification by GSH.
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White AC, Mueller JD, Laurenzi G. Kerley B lines as a radiologic manifestation of Pneumocystis carinii pneumonia. Chest 1993; 104:1642. [PMID: 8222858 DOI: 10.1378/chest.104.5.1642a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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Rakita RM, White AC, Kielhofner MA. Loa loa infection as a cause of migratory angioedema: report of three cases from the Texas Medical Center. Clin Infect Dis 1993; 17:691-4. [PMID: 8268351 DOI: 10.1093/clinids/17.4.691] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Loa loa is a filarial parasite that is endemic in West and Central Africa. Expatriates infected with L. loa commonly develop characteristic migratory angioedema called Calabar swellings. We describe three patients who presented with classical Calabar swellings for whom the diagnosis of loiasis was delayed. Unusual features that were present included a leukocytoclastic vasculitis seen on skin biopsy (case 1), a relatively short exposure to an area of endemicity (cases 1 and 3), and a normal eosinophil count on initial evaluation (cases 2 and 3). We discuss the characteristic clinical manifestations of, pathological findings of, and therapy for loiasis. With the increased frequency of international travel, L. loa infection must be considered in the differential diagnosis for patients with migratory angioedema, urticarial vasculitis, or eosinophilia.
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Cliffe IA, Brightwell CI, Fletcher A, Forster EA, Mansell HL, Reilly Y, Routledge C, White AC. (S)-N-tert-butyl-3-(4-(2-methoxyphenyl)-piperazin-1-yl)-2-phenylpropanamide [(S)-WAY-100135]: a selective antagonist at presynaptic and postsynaptic 5-HT1A receptors. J Med Chem 1993; 36:1509-10. [PMID: 8496920 DOI: 10.1021/jm00062a028] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Goodgame RW, Genta RM, White AC, Chappell CL. Intensity of infection in AIDS-associated cryptosporidiosis. J Infect Dis 1993; 167:704-9. [PMID: 8440940 DOI: 10.1093/infdis/167.3.704] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
A fluorescent monoclonal anti-Cryptosporidium antibody was used to count the oocysts in stools of 12 AIDS patients with chronic cryptosporidiosis. Oocyst excretion was present throughout the day in all 12 patients. Stool-to-stool variation in oocyst concentration was within one order of magnitude. Small variations were also found in daily mean oocyst concentration and total daily oocyst excretion in 3 patients who had multiple 24-h stool collections. However, there was a large patient-to-patient variation in mean oocyst concentration (from < 5.0 x 10(3) to 9.2 x 10(5) oocysts/mL) and 24-h total oocyst excretion (from < 6.0 x 10(6) to 1.2 x 10(9) oocysts/day). There was a significant correlation between oocyst excretion and numbers of Cryptosporidium organisms seen on small bowel biopsy. Oocyst excretion was reduced in 4 patients treated with paromomycin, but diarrhea improved only in the 2 patients with high initial oocyst excretion.
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Molinari JL, Tato P, Lara-Aguilera R, White AC. Effects of serum from neurocysticercosis patients on the structure and viability of Taenia solium oncospheres. J Parasitol 1993; 79:124-7. [PMID: 8437052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Neurocysticercosis, caused by Taenia solium, is arguably the most common parasitic disease of the central nervous system. In taeniid infections of nonhuman mammals, there is strong evidence of immunity in the intermediate host to the invasive larvae (oncospheres). This immunity, which is mediated by antibody and complement, has been exploited to develop vaccines that effectively prevent infection. To examine the immune response in humans, T. solium eggs were hatched and activated in vitro. Activated oncospheres were incubated with heat-inactivated sera from patients with neurocysticercosis with or without complement (guinea pig serum). Controls included oncospheres plus complement alone, normal human serum alone, normal serum with complement, or buffer alone. Serum from infected patients, especially with complement, markedly reduced oncosphere mobility and led to disappearance of secretory vesicles and loss of membrane integrity. Viability as assessed by staining with dimethyl-thiazolyl-diphenyl-tetrazolium was reduced from 92.5% in controls to 61.5% with immune serum and 38.8% with immune serum and complement (P < 0.01). Preliminary western blot analysis showed antigens at 22, 64, and 70 kDa recognized by all 3 sera, but not by control sera. These data suggest that sera from patients with cysticercosis can kill oncospheres in vitro and may be used to identify protective antigens.
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Abstract
Flagellate parasites isolated in Venezuela from bone marrow aspirates of a human (MHOM/VE/70/Chuao) and a dog (MCAN/VE/72/Talisman2) were subsequently identified by isozyme analysis as Leishmania colombiensis. Data are presented describing genetic similarity among Panama, Colombia, and Venezuela populations of this species.
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Das SK, White AC, Fanburg BL. Modulation of transforming growth factor-beta 1 antiproliferative effects on endothelial cells by cysteine, cystine, and N-acetylcysteine. J Clin Invest 1992; 90:1649-56. [PMID: 1430195 PMCID: PMC443220 DOI: 10.1172/jci116036] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Early passaged bovine pulmonary artery endothelial cells exposed to 0.1-2.0 ng/ml transforming growth factor-beta 1 (TGF-beta 1) showed concentration-dependent growth inhibition, as assessed by [3H]thymidine labeling and cell counts, over a 96-h interval. Most of the inhibition of [3H]thymidine labeling measured at 96 h persisted when the medium was replaced with TGF-beta 1-free medium after 24 h, but the inhibition of labeling was prevented by the presence of anti-TGF-beta 1 antibody in the replacement medium. Additions of 2 mM cysteine, 1 mM cystine, or 2 mM N-acetylcysteine at the time of the initial addition of TGF-beta 1 blocked the inhibitory effect of TGF-beta 1 on [3H]-thymidine labeling when this was assessed after 72-96 h, but not at earlier times. Prevention of the inhibitory effect on cellular proliferation produced by cysteine, cystine and N-acetylcysteine was associated with elevation of cellular glutathione that was present at 48-96 h. There was no evidence for direct inactivation of TGF-beta 1 by the thiol-amino acids. Conditioned medium from TGF-beta 1-treated endothelial cells inhibited proliferation of mink lung carcinoma (CCL64) cells, supporting a previously reported concept of autocrine production of TGF-beta 1 by the endothelial cells. The inhibitory action of the conditioned medium was partially prevented when 1 mM cysteine was added during conditioning. Thus, TGF-beta 1 treatment of endothelial cells appears to set off autocrine production by these cells of TGF-beta 1 that perpetuates the inhibition of cellular proliferation. Replenishment of cellular glutathione with thiol-amino acids counteracts the growth-inhibitory effect of TGF-beta 1 through a currently undefined mechanism.
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Bandres JC, White AC, Samo T, Murphy EC, Harris RL. Extraparenchymal neurocysticercosis: report of five cases and review of management. Clin Infect Dis 1992; 15:799-811. [PMID: 1445979 DOI: 10.1093/clind/15.5.799] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Neurocysticercosis due to parenchymal cysts carries a good prognosis regardless of therapy. Extraparenchymal neurocysticercosis (including ventricular, spinal, and subarachnoid types) carries a poorer prognosis. Most extraparenchymal cases present with hydrocephalus. Medical treatment alone in doses and schedules developed for parenchymal disease is frequently unsuccessful. For ventricular disease, most cases can be managed with shunting procedures either alone or together with the administration of antiparasitic agents (e.g., praziquantel or albendazole), without extirpation of the cysts. Subarachnoid disease was formerly associated with a case fatality rate of about 50%. However, with the combination of shunting procedures for hydrocephalus, antiparasitic agents, and, in some cases, surgical extirpation of the cysts, the prognosis is much improved. Spinal cysticercosis can be either leptomeningeal (which responds like subarachnoid disease) or intramedullary. For all forms of neurocysticercosis, the role of antiparasitic agents needs to be better defined.
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Subramanian D, Moise KJ, White AC. Imported malaria in pregnancy: report of four cases and review of management. Clin Infect Dis 1992; 15:408-13. [PMID: 1520785 DOI: 10.1093/clind/15.3.408] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Malaria is a common infection worldwide. Increased travel by pregnant women makes it likely that physicians in the United States will see cases of malaria in this population. We observed four cases of malaria during pregnancy over an 8-month period at a general hospital in the United States. These cases illustrate the association between pregnancy and severe malaria in the mother and congenital infection in the newborn. We also noted delays in diagnosis because malaria was mistaken for other common illnesses. Therapy was complicated by concerns about the safety of antimalarial agents for the fetus and newborn as well as drug resistance. While chloroquine is safe for use in pregnancy, drug resistance is now common, especially when the etiologic organism is Plasmodium falciparum. There are concerns about the safety of administering other antimalarial agents during pregnancy (e.g., mefloquine). Concerns about the safety and availability of these agents limit options for prophylaxis.
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