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At least 127 records · Page 7Linked to original sources
PubMed1999

Primary vitrectomy with perfluoro-n-octane use in the treatment of pseudophakic retinal detachment with undetected retinal breaks.

PURPOSE: This report describes the results of a prospective trial to evaluate the efficacy of pars plana vitrectomy (PPV) in conjunction with perfluoro-n-octane (PFO) as initial treatment of pseudophakic retinal detachment (RD) with no breaks diagnosed preoperatively. METHODS: Fourteen consecutive eyes presenting with pseudophakic RD in which retinal breaks could not be identified preoperatively underwent primary PPV, internal microsurgical identification of the retinal breaks with endoillumination and noncontact wide angle viewing system, PFO retinal reattachment, transscleral cryopexy or endolaser treatment of breaks, PFO-air exchange, and final injection of 20% sulfur hexafluoride. In five eyes, a scleral buckle was also used. Mean follow-up period was 18 months. RESULTS: In 13 of the 14 eyes in which no breaks had been identified preoperatively, breaks were diagnosed during surgery. Perfluoro-n-octane retinal attachment facilitated accurate microscopic treatment of retinal breaks. The retina was reattached with a single operation in all eyes. Eleven eyes had final visual acuity of 20/60 or better. Complications were minimal. CONCLUSIONS: Pars plana vitrectomy in conjunction with PFO expression of subretinal fluid is effective in the initial treatment of pseudophakic RD with no preoperative diagnosis of retinal breaks.

Adult↗
PubMed1999

Tolerance of extended-term vitreous replacement with perfluoro-n-octane and perfluoroperhydrophenanthrene mixture (phenoctane).

PURPOSE: To improve the surface visibility of perfluoroperhydrophenanthrene, we added various percentages of perfluoro-n-octane. METHODS: Twenty New Zealand white rabbit eyes underwent gas vitrectomy. One milliliter of balanced salt solution was injected into each Group 1 eye as control. Perfluoro-n-octane was added to perfluoroperhydrophenanthrene in ratios of 15:85, 25:75, and 50:50; 1 mL of each mixture was injected into the vitreous cavities of Groups 2, 3, and 4, respectively. Eyes were examined clinically and electroretinograms were performed before and 4 and 8 weeks after injection, when the rabbits were killed. Eyes were processed for light and transmission electron microscopy (TEM). RESULTS: The indices of refraction of the 15:85, 25:75, and 50:50 mixtures were 1.3275, 1.3191, and 1.3026, respectively, and the mixtures were visible in the vitreous cavity. Emulsification and mild-to-moderate dust-like opacities were observed in eyes from Groups 2 through 4; vitreous strands formed in four of the Group 4 eyes. The retinae were attached. Electroretinographic responses were normal, except in one eye with cataract. Light microscopy showed normal retinal architecture, with some macrophages with intracytoplasmic vacuoles on the surface of the inferior retina or in the vitreous cavity. Fingerprint disfigurement of photoreceptor outer segments was seen in some Group 3 and 4 eyes under TEM. CONCLUSIONS: Minimal changes were induced by the 15:85 mixture in the rabbit eye. The mixtures of 25:75 and 50:50 produced some ultrastructural changes of the retina. The mixtures were visible under water.

Animals↗
PubMed2002

The 2:1 complex of maleic acid and 1,4-diazabicyclo[2.2.2]octane: hydrogen-bonded sheets linked by C-H...O hydrogen bonds.

In the title complex, 1,4-diazoniabicyclo[2.2.2]octane bis(hydrogen maleate), C(6)H(14)N(2)(2+).2C(4)H(3)O(4)(-), the C(4)H(3)O(4)(-) and C(6)H(14)N(2)(2+) ions, derived from maleic acid and 1,4-diazabicyclo[2.2.2]octane, respectively, are disordered across a mirror plane in space group Cmc2(1), and they are linked by two nearly linear N-H...O hydrogen bonds, with N...O distances of 2.662 (3) and 2.614 (4) A, and N-H...O angles of 173 degrees. The crystal structure consists of sheets with reticulations of 3.3792 (4) A in stratum and 7.3892 (8) A in width. The sheets are linked by C-H...O hydrogen bonds.

Journal Article↗
PubMed2003

Two isomers of 2,4-dibenzyl-8-azabicyclo[3.2.1]octan-3-ol.

The crystal structures of the title compounds, 2 alpha,4 alpha-dibenzyl-3 alpha-tropanol (2 alpha,4 alpha-dibenzyl-8-methyl-8-azabicyclo[3.2.1]octan-3 alpha-ol), C(22)H(27)NO, (I), and 2 alpha,4 alpha-dibenzyl-3 beta-tropanol (2 alpha,4 alpha-dibenzyl-8-methyl-8-azabicyclo[3.2.1]octan-3 beta-ol), C(22)H(27)NO, (II), show that both compounds have a piperidine ring in a chair conformation and a pyrrolidine ring in an envelope conformation. Isomer (I) is asymmetric, the benzyl groups having different orientations, whereas isomer (II) is mirror symmetric, and the N and O atoms, the C atom attached to the hydroxy group, and the methyl C atom attached to the N atom lie on the mirror plane. In the crystal structures of both (I) and (II), the molecules are linked together by intermolecular O-H...N hydrogen bonds to form chains that run parallel to the a direction in (I) and parallel to b in (II).

Aza Compounds↗
PubMed1994

Petrol octane booster and methaemoglobinaemia.

We highlight the case of a 35-year-old male who suffered a respiratory arrest as a result of methaemoglobinaemia secondary to skin contamination and inhalation of petrol octane booster following a road traffic accident. It is important that petrol octane booster is stored safely in leak-proof containers and that suitable warnings are displayed to alert the user of potential toxicity.

Adult↗
PubMed1993

Antiulcer agents. III. Synthesis and antiulcer activity of N-[3-(3-piperidinomethylphenoxy)propyl]pentacyclo[4.2.0.0(2,5).0(3,8).0 (4,7)]-octane carboxamides and related compounds.

The synthesis and antiulcer activity of highly strained cage compounds such as pentacyclo[4.2.0.0(2,5).0(3,8).0(4,7)]-octane (cubane), pentacyclo[4.3.0.0(2,5).0(3,8).0(4,7)]nonane (homocubane) and pentacyclo[5.3.0.0(2,4).0(3,6).0(5,8)]decane are described. Of the compounds obtained, N-[3-(3-piperidinomethylphenoxy)propyl]-4-piperidinocarbonylpen tacyclo [4.2.0.0(2,5).0(3,8).0(4,7)]octane carboxamide (26a) and N-[3'-(3'-piperidinomethylphenoxy)propyl]-1-bromo-9, 9-ethylenedioxypentacyclo[4.3.0.0(2,5).0(3,8).0(4,7)[nonane]-4- carboxamid e (26q) showed more potent antiulcer activity with very good cytoprotective ability in the HCl.ethanol-treated rat model. Compounds 26a and 26q exhibited H2-receptor antagonist potency (in vitro) comparable to that of ranitidine, but did not inhibit histamine-stimulated acid secretion (in vivo) in the gastric fistula rat model, when orally administered in the dose range at which antiulcer and cytoprotective activities were seen. The structure-activity relationships are discussed.

Animals↗
PubMed1994

Immunomodulatory agents: dioxothiadiazabicyclo[3.3.0]octanes and their 2-spiro derivatives.

A series of 6,8-dioxo-3-thia-1,7-diazabicyclo[3.3.0]octanes and a series of 6,8-dioxo-3-thia-1,7-diazabicyclo[3.3.0]octane 2-spiro derivatives were synthesized from L-(-)-R-cysteine ethyl ester in two steps. The synthetic route involved condensation of the amino acid with an appropriate aldehyde or ketone, then a further condensation of the resultant ethyl thiazolidine-4-carboxylate with an isocyanate or an isothiocyanate. The proliferative response to human lymphocyte mitogen (phytohemagglutinin) was used as a primary screening assay for most of the thiadiazabicyclic compounds in comparison with levamisole. Furthermore, the most active compounds were tested for ability to release soluble receptors (sRIL-2) after mitogenic stimulation of T cells and for ability to activate macrophage oxidative metabolism measured by chemiluminescence. Most compounds were active in all three tests and some showed dose-dependent activity.

Adjuvants, Immunologic↗
PubMedDate not supplied

[Chemical ribonucleases. 4. Analysis of the fragment structure of chemical ribonucleases based on 1,4-diazabicyclo[2.2.2]octane].

Artificial ribonucleases of the ABLkCm series were synthesized. They consist of a lipophilic alkyl radical (Et, n-C14H29, or C15H31) A, an "RNA-binding domain" B (bisquaternary salt of 1,4-diazabicyclo[2.2.2]octane), a "catalytic domain" Cm [histamine (C1) or histidine (C3) residue], and a "linker" Lk that joins the "domains" B and Cm [here, k is the number of methylene units (one or three) in the linker]. The effect of the "domain structure" on the catalytic properties of the chemical ribonucleases was analyzed using seven compounds of this series (ABL1C1, ABL3C1, ABL3C3, AC1, AB, BL2, and BL3C3). The catalytic activity of the compounds was assessed in the reaction of hydrolysis of the in vitro transcripts of human tRNA(Lys) and yeast tRNA(Asp) under physiological conditions. It was shown that only chemical ribonucleases that involve all the fragments of the ABLkCm construct can hydrolyze the substrate tRNA at a high rate (90% of tRNA is hydrolyzed for 10 h at 37 degrees C). The activity of the compounds is largely determined by the presence of a long lipophilic radical linked to 1,4-diazabicyclo[2.2.2]octane and a long linker, which joins the RNA-hydrolyzing and RNA-binding fragments. The results indicate an important role of hydrophobic interactions in the acceleration of the RNA hydrolysis reaction. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2002, vol. 28, no. 4; see also http://www.maik.ru.

Catalysis↗
PubMedDate not supplied

Synthesis of new N-substituted cyclic imides with an expected anxiolytic activity. XVI. Derivatives of 1-acetoxy-7,7-dimethylbicyclo[2.2.2]octan-5-one-2,3-dicarboximide.

The preparation of a potential anxiety-relieving compounds N-[4-(4-aryl)-1-piperazinyl)butyl]-1-acetoxy-7,7-dimethyl-bicyclo[2.2.2]octan-5-one-2,3-dicarboximides has been described. N-[4-(4-2-methoxyphenyl)-1-piperazinyl)butyl]-1-acetoxy-7,7-dimethyl-bicyclo[2.2.2]octan-5-one-2,3-dicarboximide III showed a strong sedative effect in Writh's test.

Animals↗
PubMed1991

5-[4-(omega-dialkylaminoalkoxy)phenylmethylene] -1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-ones with platelet antiaggregating and other activities.

The synthesis of 5-[4-(omega-dialkylaminoalkoxy)phenylmethylene]- 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-ones 3 by reaction of some 4-(omega-dialkylaminoalkoxy)benzaldehydes with (+)-1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-one in the presence of sodium methoxide is described. Some aminoethers 3 showed platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid, as well as weak antiarrhythmic activity in rats and moderate infiltration anesthesia in mice.

Anesthetics, Local↗
PubMed1990

[Use of perfluoro-octane liquid in the treatment of giant tears with inversion of the retina: preliminary results].

Five consecutive cases of giant tears with retinal inversion were easily and successfully treated using vitrectomy and silicone oil injection after repositioning of the retina with perfluoro-octane. The good initial results show the interest of this technique compared with the incarcerations or with the manipulation of the retina and of the perfluoro-octane compared with the other liquid perfluorocarbons.

Adult↗
PubMed1990

omega-Dialkylaminoalkyl ethers of 5-endo-dialkylamino-1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-hydroxyimines with platelet antiaggregating, antiarrhythmic and local anesthetic activities.

The synthesis of 1,3,3-trhimethyl-5-endo-(1-piperidinyl)- and -5-endo-(4-morpholinyl)-2- oxabicyclo [2.2.2]octan-6-hydroxyimine 3 and 4 starting from 5-endo-bromo-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-hydroxyimine+ ++ and excess piperidine or morpholine is described. Compounds 3 and 4 gave a series of omega-dialkylaminoalkyl ethers 5 by reaction as sodium salts with omega-chloroalkyldialkylamines in DMF solution. Some of aminoethers 5 showed in mice an appreciable antiarrhythmic and local anesthetic activity, as well as a platelet antiaggregating activity in vitro comparable to that of acetylsalicylic acid.

Amines↗
PubMedDate not supplied

[Activity of lipoxygenase incorporated into reversed micelles of aerosol OT in octane].

Soybean lipoxygenase (EC 1.13.11.12) incorporated into the reversed micelles of aerosol OT in octane has been studied for its catalytic properties. The enzyme is shown to preserve up to 10% activity as compared with the activity in the aqueous solution. In this case Km of lipoxygenase for linoleic acid increases from 10(-5) M to 5 X 10(-4) M. The activity of lipoxygenase is maximal, the aerosol OT concentration being 0.03 M and a degree of reversed micelle hydratation 40. Cationic detergents of the cetyltrimethyl ammonium bromide type are not good to form reversed micelles of lipoxygenase, since they inhibit the latter with IC50 = (4 divided by 6) x 10(-4) M. The lipoxygenase preparations in reversed micelles of aerosol OT in octane may be used to synthesize natural metabolites of polyunsaturated fatty acids, for instance of eicosanoids.

Colloids↗
PubMed1989

Amides of 1,3,3-trimethyl-n-[(2-pyridyl)methyl]-2-oxabicyclo [2.2.2]octan-6-amine with depressant and antiarrhythmic activities.

The synthesis of 1,3,3-trimethyl-N-[(2-pyridyl)methyl]-2- oxabicyclo [2.2.2]octan-6-amine (II) (exo, endo mixture) starting from 1,3,3-trimethyl-N-nitro-2-oxabicyclo [2.2.2]octan-6-imine (I), as well as of a series of amides (III) derived from the above amine, is described. Some compounds (III) showed remarkable depressant and antiarrhythmic activities in rats and mice, respectively, whereas the clofibric acid amide (III e) showed an appreciable hypolipidemic activity in rats. Moreover, the above compounds usually exhibited a moderate infiltration anesthesia in mice, as well as a weak hypotensive and bradycardic activity in rats.

Amides↗
PubMed1986

1,3,3-Trimethyl-N-(2-pyridyl)-2-oxabicyclo[2.2.2]octan-6-amine derivatives with hypotensive and other activities.

The synthesis of 1,3,3-trimethyl-N-(2-pyridyl)-2-oxabicyclo-[2.2.2]octan-6-amine (cis, trans mixture) starting from 1,3,3-trimethyl-N-nitro-2-oxabicyclo[2.2.2]octan-6-imine, as well as of a series of amides (V) derived from the above amine, is described. Some compounds (V) showed strong hypotensive activity in rats. Effects on heart rate and antiarrhythmic activity in rats, as well as local anesthetic activity in mice, are also reported.

Anesthetics, Local↗
PubMed1984

Inhibition of angiotensin converting enzyme by 2-[N-[(S)-1-carboxy-3-phenylpropyl]-L-alanyl]-(1S,3S,5S)-2-azabicyclo [3.3.0]octane-3-carboxylic acid (Hoe 498 diacid). Comparison with captopril and enalaprilat.

The interaction of angiotensin converting enzyme (ACE) with 2-[N-[(S)-1-carboxy-3-phenylpropyl]-L-alanyl]-(1S,3S,5S) - 2 - azabicyclo[3.3.0]octane - 3 - carboxylic acid (Hoe 498 diacid) and its ester 2-[N-[(S)-1-ethoxycarbonyl-3 - phenylpropyl] - L - alanyl]-(1S,3S,5S)- 2-azabicyclo[3.3.0]octane-3-carboxylic acid (Hoe 498) was studied at pH 7.5 in the presence of 300 mmol/l sodium chloride with furanacryloyl-Phe-Gly-Gly as substrate. Hoe 498 diacid inhibits ACE with a Ki value of 7 pmol/l. It is both a slow-and tight-binding inhibitor; the mode of inhibition is fully competitive. Binding of Hoe 498 diacid to ACE proceeds by a two-step mechanism E+I in equilibrium EI in equilibrium EI* in which the inhibitor rapidly binds to enzyme to form an initial enzyme-inhibitor complex which then undergoes a slow isomerization. The interaction of Hoe 498 diacid with ACE is compared to that of the two other potent inhibitors, captopril and enalaprilat.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1984

Interaction of bicyclo-octane analogs of amantadine with ionic channels of the nicotinic acetylcholine receptor and electrically excitable membrane.

A series of bicyclo-octane analogs of amantadine was investigated for their actions on ionic channels of electrically excitable membrane and of nicotinic acetylcholine receptors in frog sartorius muscles. Amantadine and three of its amine-substituted bicyclo-octane analogs (ID 11, 33 and 36) blocked neuromuscular transmission in a concentration-dependent manner. The dipropylaminomethyl analog (ID 36) also potentiated the directly elicited twitch concurrent with a prolongation of the directly elicited action potential; there was no block of delayed rectification. The peak amplitude of the end-plate current at -90 mV was reduced in a nearly equipotent manner by amantadine and ID 11, 33 and 36, but these three analogs were more potent than amantadine in shortening the time constant of end-plate current decay. The pattern of nonlinearity in the current/voltage relationship and area of negative slope conductance coupled with the depression and shortening of the end-plate current suggest that these analogs block neuromuscular transmission by interacting with the ionic channel of the acetylcholine receptor. Because carboxy-substituted analogs were ineffective and amine-substituted ones were effective, it appears that the site(s) which controls the opening and closing of the ionic channel require(s) a drug to penetrate a lipid barrier to a hydrophilic site in the membrane.

Action Potentials↗
PubMed1994

5-[[omega-(Dialkylamino)alkoxy]methylene]-1,3,3-trimethyl-2- oxabicyclo [2.2.2.]octan-6-ones with hypotensive, local anesthetic, antiarrhythmic and other activities.

The synthesis of 5-[[omega-(dialkylamino)alkoxy]methylene]-1,3,3-trimethyl-2- oxabicyclo[2.2.2]octan-6-ones by reaction of (+)-5-(hydroxymethylene)-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan- 6-one with a series of omega-(chloroalkyl)dialkylamines in the presence of potassium carbonate is described. Some compounds showed strong hypotensive, local anesthetic and antiarrhythmic activity in rats and mice, as well as moderate analgesic, antipyretic and in vitro platelet antiaggregating activity.

Analgesics, Non-Narcotic↗