Mohamed A. Hassan

Topical mitomycin C application is effective in management of localized caustic esophageal stricture: A double-blinded, randomized, placebo-controlled trial

BACKGROUND Frequent sessions of endoscopic dilatation are usually required in the management of benign esophageal strictures, especially caustic induced ones. Topical mitomycin C (MMC) has been recently used in the management of resistant strictures. This study evaluated the efficacy of MMC application in prevention of stricture recurrence after endoscopic dilatation. PATIENTS AND METHODS This double-blind, randomized, placebo-controlled trial included forty patients with caustic esophageal strictures dating from January 2008 to October 2010. Patients were randomized into 2 groups to undergo endoscopic dilatation with application of either MMC versus placebo on stricture site. Regular follow up and re-evaluation were done after 6 months of management. The number of dilatation sessions needed for resolution of dysphagia in each group was our primary outcome. RESULTS During the specified follow up period, 80 % of strictures in the MMC group got completely resolved compared to only 35% in the placebo group. The mean number of dilatation sessions needed in the MMC group was n = 3.85 ± 2.08 compared to n = 6.9 ± 2.12 in the placebo group which was statistically significant (p < 0.001). CONCLUSION Mitomycin C application significantly reduced the number of dilatation sessions needed to alleviate dysphagia in patients with caustic esophageal strictures.

Topical mitomycin C can effectively alleviate dysphagia in children with long-segment caustic esophageal strictures.

Caustic ingestion in children and the resulting long esophageal strictures are usually difficult to be managed, and eventually, esophageal replacement was required for cases refractory to frequent dilatation sessions. Topical mitomycin C (MMC) application has been used recently to improve the results of endoscopic dilatation for short esophageal strictures. The study aims to assess the role of MMC application in management of long-segment caustic esophageal strictures. From January 2009 to June December 2013, patients presented with long caustic esophageal stricture (>3 cm in length) were included in this study and subjected to topical MMC application after endoscopic esophageal dilatation on multiple sessions. Regular follow-up and re-evaluation were done. A dysphagia score was used for close follow-up clinically; verification was done radiologically and endoscopically. During the specified follow-up period, 21 patients with long caustic esophageal stricture were subjected to topical MMC application sessions. Clinical, radiological, and endoscopic resolution of strictures occurred in 18 patients (85.7% cure rate). Number of dilatation sessions to achieve resolution of dysphagia was (n = 14.3 ± 5.7) with application of mitomycin two to six times. There was no recurrence in short- and mid-term follow-up. No complications were encountered related to topical MMC application. MMC is a promising agent in management of long-segment caustic esophageal strictures. Long-term follow-up is needed to prove its efficacy and to evaluate potential long-term side-effects of MMC application.

N- vs. S-PTC Alkylation of 5-Carboethoxy-2-thiouracil And Its Reactivity Towards Some Nucleophilic Reagents

The reactivity of 5-carboethoxy-2-thiouracil (1) toward alkylation by different organohalogen compounds under phase-transfer catalysis (PTC) conditions has been investigated to give S-monoalkylated products and/or simultaneous S- and N-dialkylated products. Also, nucleophilic additions of methylmagnesium iodide, hydroxylamine, and hydrazine to 5-carbethoxy-2-thiouracil (1) have been investigated. The structures of all products have been confirmed by elemental analysis and spectral data.

Phase-Transfer Catalyzed Alkylation and Cycloalkylation of 3-Substituted-1H-pyrazol-2-in-5-ones in the Absence or Presence of Carbon Disulphide

Abstract PTC-alkylation of 3-substituted-1H-pyrazol-2-in-5-ones by different organohalogen reagents at 25ˆC in the presence of tetrabutylammonium bromide as-catalyst was investigated either in the absence or presence of CS2. This work aims to study the comparative reactivity of N-versus O-versus C-alkylation and cycloalkylation.

N-VS. O-(S-) PTC ALKYLATION OF 3-CYANO-4,6-DIMETHYL-2-OXO (THIOXO)-1,2-DIHYDROPYRIDINE

Abstract N-Alkylation versus O-/or S- alkylation reactivity of 3-cyano-4,6-dimethyl-2-oxo(thi-oxo)-1,2-dihydropyridine have been investigated under phase transfer catalysis conditions.

FACILE SYNTHESIS OF 4-SUBSTITUTED 2-PYRAZOLIN-5-ONES UNDER PHASE TRANSFER CATALYSIS

Abstract Nucleophilic displacement of organohalogen compounds by 2-pyrazolin-5-ones (1) in absence/or presence of carbon disulphide or phenyl isothiocyanate under phase transfer catalysis conditions have been studied to give 4-substituted-2-pyrazolin-5-ones (2-8).

NUCLEOPHILIC ADDITION REACTIONS ON 3-CARBETHOXY- 5,7-DIMETHOXYCOUMARIN

ABSTRACT 3-Carbethoxy-5,7-dimethoxycoumarin (2) underwent Michael addition and addition–cyclization of some active methylene compounds under different reaction conditions to give the adducts (3–7). Addition of phenylmagnesium bromide onto (2) yielded the tertiary alcohol (8). Addition of ammonia derivatives on (2) afforded the 3-carboxamides (9a–c) and azine (10). Furthermore, alcoholysis and hydrolysis yielded the coumarins (11a–c).

Substituted Quinolinones, Part 12: Heterocyclization Reactions of 3‐(3‐Chromonyl)acryloylquinolinone with Some Bifunctional Nucleophiles

Abstract 4‐Hydroxy‐1‐methyl‐3‐[E‐3‐(4‐oxo‐4H‐chromen‐3‐yl)acryloyl]quinolin‐2(1H)‐one (3) was smoothly obtained via a one‐pot aldol dehydration reaction of 3‐acetyl‐4‐hydroxyquinolin‐2(1H)‐one with 3‐formylchromone and was utilized to prepare miscellaneous triheterocyclic systems containing the quinolinone moiety. Both the α,β‐unsaturated ketone side chain and the γ‐pyrone ring in compound 3 were subjected to nucleophilic cyclization with certain 1,2‐ and 1,3‐bifunctional N,N‐, N,O‐, N,C‐, and O,C‐nucleophiles under different reaction conditions. Many pyrazolinyl‐, isoxazolinyl‐, pyrimidinyl‐, and pyridinylquinolinones bearing other six‐ or five‐membered heterocyclic systems have been conveniently synthesized using more than one synthetic route. Dedicated to the memory of the late Professor Sayed Ibrahim El‐Nagdi.

PTC-ALKYLATION AND MICHAEL ADDITION OF INDANONES; SYNTHESIS OF 2-SUBSTITUTED INDANONES

Abstract The reactivity of indan-1-one (1a) and or indan-1,3-dione (1b) towards alkylation in the absence or presence of carbon disulphide under phase transfer catalysis (PTC) conditions has been investigated to give indanone derivatives 2–9. Michael addition of (1a,b) to α,β-unsaturated carbonyl compounds under the same FTC conditions yielded the adducts 10–16.

Approach for the three-body force effect in the optical limit approximation: Application to hadron-deuteron elastic scattering at high energies

An approach for the three-body force effect in the optical limit approximation is suggested. The differential cross sections of p ?, and ?? ? d elastic scattering at 1.75 and 12.8 GeV/c for incident proton, 2 GeV/c for anti-proton and 9 GeV/c for pion are studied. The D-state and phase variation effects are considered. The experimental data is well described including the 2?-exchange three-body force. The three-body force effect, in this approach, plays a principal role over the complete range of momentum transfer square where the data is available.