Coordinative polymerization of p-substituted phenyl glycidyl ethers, 1. Effect of electron-donating groups

A series of p-substituted glycidyl phenyl ethers

1 IUPAC nomenclature: 2,3-epoxypropyl phenyl ether.

with electron donor groups was prepared using a multistep synthetic method. These compounds were polymerized using four of the most common aluminium-based coordinative initiators, (C₂H₅)₃Al/H₂O (the Vandenberg catalyst), (C₂H₅)₃Al/CH₃COCH₂COCH₃/H₂O (the Vandenberg chelate catalyst), [(CH₃)₂CHO&]₂Al? O? Zn? O? Al[OCH(CH₃)₂]₂ (the Teyssié catalyst) and [(CH₃)₂CHO]₃AV/ZnCI₂ (the Price catalyst), all with different Lewis acid character. The influence of the electron-donor group on the characteristics and conversion was studied. Generally speaking, both the Vandenberg and the Teyssié catalysts yield mostly an insoluble polymer fraction, whereas the Price catalyst was shown to be the most stereoselective catalyst. Moreover, the Vandenberg chelate catalyst gave the highest molecular weight, the Price catalyst the lowest. Thermal characteristics of polymers were studied by means of differential thermal analysis to obtain glass transition temperatuures, melting temperatures and fusion enthalpies.     

Suppression of Immune Parameters in Animal Models of Morphine Dependence

Implantation of pellets containing 75 mg of morphine induced short term (4 day) morphine dependence and markedly reduced total number of spleen cells of BALB/c mice, without affecting total body or liver weight. Polyclonal responses induced by anti-CD3 antibodies, Concanavalin A or Escherichia coli lipopolysaccharide in the remaining spleen cells of morphine-treated mice were also inhibited. Cytofluorimetric analysis indicated that the proportion of major functional lymphocyte populations (Ig⁺, CD3⁺, CD4⁺ and CD8⁺ lymphocytes) were not significatively changed in the spleen from morphine-dependent mice. Furthermore, expression levels of surface Ig, CD3, CD4, and CD8, were similar in spleen cells from control or morphine-treated mice. So, morphine dependence in BALB/c mice under these controlled conditions results in a specific defect in lymphoid cell number and function, with no incidence on body weight or particular lymphocyte subsets.     

A Trivalent Enzymatic System for Uricolytic Therapy of HPRT Deficiency and Lesch-Nyhan Disease

Purpose

Because of the evolutionary loss of the uricolytic pathway, humans accumulate poorly soluble urate as the final product of purine catabolism. Restoration of uricolysis through enzyme therapy is a promising treatment for severe hyperuricemia caused by deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT). To this end, we studied the effect of PEG conjugation on the activity and stability of the enzymatic complement required for conversion of urate into the more soluble (S)-allantoin.

Methods

We produced in recombinant form three zebrafish enzymes required in the uricolytic pathway. We carried out a systematic study of the effect of PEGylation on the function and stability of the three enzymes by varying PEG length, chemistry and degree of conjugation. We assayed in vitro the uricolytic activity of the PEGylated enzymatic triad.

Results

We defined conditions that allow PEGylated enzymes to retain native-like enzymatic activity even after lyophilization or prolonged storage. A combination of the three enzymes in an appropriate ratio allowed efficient conversion of urate to (S)-allantoin with no accumulation of intermediate metabolites.

Conclusions

Pharmaceutical restoration of the uricolytic pathway is a viable approach for the treatment of severe hyperuricemia.

     

New reactive polyethers: preparation and synthetic possibilities

Starting from 4-methoxycarbonylphenyl glycidyl ether and unfunctionalized phenyl glycidyl ether, samples of highly regio- and stereoregular linear homo- and copolymers were synthesized using the ionic coordinative initiator system aluminium isopropoxide/ZnCl₂. The polymers were first transformed into carboxylic acid derivatives and then into highly reactive carboxylic acid chlorides with high yields and conversions. The use of all these synthesized polymers was tested by transforming them into the corresponding 4-nitrobenzyl ester using different synthetic procedures. Finally, the scope of the methodology studied was tested by using it to synthesize a set of new polymers containing different complex groups such as: 18-crown-6, biphenyl-4-carbonitrile, anthraquinone, (1R)-nopol, (-)-inosine and 4-dodecylaniline, which are in general obtained with good yields and conversions.     

Acquired partial lipodystrophy treated with poly-L-lactic acid and hyaluronic acid fillers: a case report

Acquired partial lipodystrophy (APL), also known as Barraquer-Simons syndrome, is a rare disorder characterized by progressive fat loss in the upper body. Use of poly-L-lactic acid and hyaluronic acid (HA) fillers for the treatment of APL is neither approved by the Food and Drug Administration nor described in the literature. Herein, we describe a case of APL that achieved significant improvement in facial volume following treatment with combination poly-L-lactic acid and HA fillers.     

The Angel Wings Incision: A novel solution for mastectomy patients with increased lateral adiposity

Many techniques have been proposed to address the problem of increased lateral adiposity in patients undergoing mastectomy, however, there is no standard approach. This cosmetic deformity at the lateral end of the mastectomy scar, also known as a dog ear, is especially common in obese patients. This defect can be unsightly and uncomfortable. We describe a technique for creating a winged incision to eliminate the dog ear deformity. The Angel Wings Incision results in tissue flaps that create a smooth body contour upon closure in patients with increased lateral adiposity. The technique is reproducible, aesthetically pleasing, and improves patient satisfaction.