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Biomedical subjects

A Wilk

Publications and source records attributed to A Wilk.

At least 55 records · Page 3Linked to original sources
PubMed1994

[The covering of radionecrosis in plastic surgery. Apropos of a series of 20 cases].

Twenty radionecroses with various locations were operated on between 1982 and 1993 in the Plastic Surgery Department at Strasbourg. Flap covers were performed. The results and indications as a function of localization and of the size and quality of the structures involved was analyzed for these radio-induced lesions. A wide range of therapeutic option are available to the plastic surgeon who must chose the most reliable reconstruction technique after the most extensive exeresis possible. Muscle and pediculated musculo-cutaneous flaps are preferred due to their safety, their vascular, trophic and anti-infectious quality and their excellent capacity of coverage.

Adult↗
PubMed1993

Antibodies to recombinant fragment 212-276 of protein C specifically recognize the intact human molecule.

The peptide fragment Pro212-Ile276 of human protein C was produced as a part of a fusion protein in Escherichia coli. The identity of the peptide was confirmed by immunoblotting experiments using specific antibodies to intact protein C. The peptide Pro212-Ile276 was isolated from the fusion protein after mild hydrolysis with formic acid by gel filtration and reverse-phase HPLC. This peptide fragment was used to produce antibodies specific for the heavy chain of protein C which recognized native protein C present in blood plasma. Antibodies to intact protein C reacted also with the Pro212-Ile276 peptide fragment, indicating that this region is immunogenic in intact protein C and may represent a native epitope.

Amino Acid Sequence↗
PubMed1993

[Reconstruction of the upper jaw. Apropos of 3 cases].

In this article, we review our personal experience in 3 patients who underwent a maxillectomy for tumor and we discuss the different reconstructive techniques available. We believe that distant pediculed flaps and free flaps give the best result for the functional and cosmetic point of view.

Aged↗
PubMed1992

Synthesis of a gene encoding bovine substance P precursors and its expression in Escherichia coli.

Using an efficient Escherichia coli expression system, we have been able to obtain the precursor of substance P, alpha-preprotachykinin (alpha PPT). The alpha PPT protein is produced in E. coli as a fusion to beta-galactosidase, and accumulates in the cytoplasm as insoluble inclusion bodies. We also produced protachykinin (alpha PT), i.e., alpha PPT without a signal peptide. Further purification and characterization of the alpha PPT and alpha PT polypeptides strongly suggest that fully purified products can be obtained using our procedures.

Amino Acid Sequence↗
PubMed1992

[The use of Sorbsan in the treatment of the donor site of skin transplantations].

Sorbsan is a new dressing composed of alginate fibers extracted from seaweed. It is claimed to have important hydrophilic, haemostatic and biocompatible qualities. Sorbsan was used in the treatment of the donor site of split skin grafts in 52 patients operated in this department from 1988 to 1990. The patients of this series required a skin graft for various reasons as detailed below: a) skin burns in 24 cases; 2) covering of a muscle flap used in the treatment of sacral pressure sores in 15 cases; c) 13 cases of loss of substance from other various causes. Healing time averaged 16.8-13.4 and 9.3 days respectively in the three groups reported above. In 85% of cases, healing was achieved in a period variable between one and two weeks and a half, varying in accordance with patient age and general conditions. The speed of healing, particularly where thin grafts were taken, allowed multiple split skin grafts to be taken from the same donor site, facilitating the treatment of extensive skin burns. The dressing can be removed with ease with only minimal discomfort to the patient. The incidence of side effects such as itching and scar hypertrophy or pigmentation is low. We haven't noticed any allergic reaction in this series. We found the use of this dressing satisfying in the treatment of donor sites of split skin grafts, particularly in terms of patient comfort and speed or healing.

Adolescent↗
PubMed1992

[Diaphragmatic hernia complicating omentoplasty after thoracic wall excision. Reflections apropos of 2 cases].

The authors relate two case-reports of diaphragmatic hernia occurring after antero-lateral chest-wall resection and repair with an omental flap. Both patients had undergone a prior lung resection for bronchogenic cancer, and the indication for chest-wall resection was parietal neoplastic recurrence. In both patients, the omental flap was brought up to the chest wall defect by a direct transdiaphragmatic route; prosthetic material was note used. The hernia presented once as early post-operative evisceration, and once as proximal obstruction due to gastric herniation. The causes of these two complications are analysed. Omentoplasty was justified twice, since the latissimus dorsi had been severed during the prior thoracotomy. Prosthetic material might have been useful to one of the patients, but not to the second who had undergone pneumonectomy. The transdiaphragmatic passage of the omentoplasty was certainly responsible for the herniae and should be avoided.

Aged↗
PubMed1992

[Mini-forum: rhinoplasty by external approach. Collumello-trans-alar approach of open rhinoplasty: advantages].

For several years, the authors have been using a columellar transalar incision through the medial crus along the nasal septum, reaching the vault and continued laterally by a transalar cartilaginous incision. The nasal tip is thus opened like a car-hood, leaving the alar cartilage attached to the skin and exposing the triangular cartilage and the nasal septum. This approach allows septoplasty to be performed with excellent exposure. The tip is easily revised backwards allowing anomalies to be viewed directly. The advantages of this external approach compared with the classical external Rethi's approach are multiple: simplicity and rapidity of the technique, excellent access to triangular cartilages and the triangular-septum junction; possibility of always going from an endonasal approach to an external one and excellent access to the tip. Moreover, there is no long term swelling of the tip. The indications of this external approach are asymmetry of the tip, excessive tip projection, saddle nose deformities and secondary rhinoplasties. No complication has been observed in a series of 32 patients with a follow-up of 6 to 48 months. There is no disturbance of the tip position and the skin scar is imperceptible.

Bone Transplantation↗
PubMed1992

[Our experience of infectious risk in prosthetic breast surgery].

This retrospective clinical study was made to help determine the signs of infectious or healing problems in candidates for prosthetic breast surgery. It concerns 80 patients with 108 breast implants (44 breast reconstructions, 21 cases of hypoplasia, 8 breast asymmetric, 20 secondary procedures, 15 of them being changes of expansion implants by definitive implants). Thirty one infectious complications (28.7%) were noted. In 22 cases it consisted of a resolutive hyperthermia. Nine cases of local complications were noted, with four implant exposures (3%). Bacteriological samples were analyzed and were positive in four out of nine (Staphylococcus aureus). In 8 out of the 9 cases the initial procedure consisted in a breast reconstruction. All 8 patients underwent postoperative radiotherapy after the initial mastectomy (Patey). The implant type (implantable, pre-filled, expansion prosthesis), its location (retromuscular), the type of surgery (asymmetrical breast musculocutaneous or fasciocutaneous flap) don't seem to be responsible in the genesis of the complications. This retrospective study could not help determine which protocol of antistaphylococcal antibiotherapy suits lest. Infectious problems arose with or without antibiotics.

Adult↗
PubMed1992

[Lift mask with use of a malleable implant: BOP S.P. Initial results].

The mask lift, the latest technique for facial rejuvenation, comprises a large remodelling of the frontal and orbito-malar area. The modelling resections by bone-grinding are essentially designed to taise the superior orbital rim, but by the onlay grafts on the malar bone as well as the ones on the superior orbital rim many problems occur due to the donor site (autogenous bone), their biocompatibility and eventual resorption or integration. It is therefore proposed to use BOP S.P. as an onlay graft, a synthetic and biocompatible material already used in neurosurgery for cranioplasties with good results. Its essential advantage over other implants is its wax like consistency and its progressive adhesion to the bone, which allows onlay grafts to be placed wherever required; the modelling is fast, the result are immediately controllable and it is stable after a few hours hardening. BOP S.P. is essentially used as onlay graft material for mask lifts, but has also been successfully tested on 4 facial contour reconstructions for corrections after major traumatic injuries. No complication has been observed in a series of 9 cases but a one year follow-up is too short.

Biocompatible Materials↗
PubMed1991

[Our own experience in the treatment of hypotrophy and ptosis of the breast].

The outcome of surgical of small, ptotic breasts is reported in a retrospective series of fifteen patients operated between 1983 and 1989. Seven patients underwent breast augmentation by insertion of breast implant supplemented in one case by a dermopexy while eight patients underwent cutaneous and glandular remodeling alone. Simple breast augmentation with breast implant gave good results with mild to moderate ptosis (i.e. when the distance between the inferior margin of the clavicle and the upper margin of the areola was equal to or less than 17 cm) provided that: the subareolar segment III did not exceed 5 cm, the skin had good static qualities for breast suspension, the amount of glandular, adipose and cutaneous tissue present allowed the prothesis to be covered by a sufficiently thick layer. With breast ptosis greater than 17 cm or when segment III exceeded 5 cm, cutaneous remodeling by dermopexy was associated with insertion of breast implant. In this group of patients treated, either by breast implant alone, or associated with dermopexy, results were good in 33%, and satisfactory in 50% of cases. Better results were obtained in patients with marked ptosis and breasts which, although hypotrophic, conserved a amount of adipose and glandular tissue sufficient to allow breast reconstruction by soft tissue remodeling alone (without the insertion of an implant). Patients in this group were treated by glandular and cutaneous remodeling with good to excellent results in 80% of cases.

Adult↗
PubMed1991

[Sacral bedsore: an evaluation of 10 years' treatment with the gluteus maximus muscle].

The authors review the notes of 40 patients who underwent surgery for large sacral pressure sore over the last 10 years. In most cases a gluteus maximus flap with skin graft has been employed to cover sacral sore, as originally described by Ger in 1971. The results of this series are then compared with those published by other authors using different techniques, with particular attention to gluteus maximus musculo-cutaneous island flaps and purely cutaneous flaps. All procedures carry a small mortality rate because of the advanced age and frail conditions of most patients. In our series 2 patients died in the postoperative period; in all the others we eventually achieved a sound healing of the sacral sore. We conclude that the gluteus maximus rotation flap is a safe and effective for the treatment of this condition. Its only major drawback is represented by the prolonged period required for the epithelisation by secondary intention of some fairly frequent areas of failure on the skin graft. The importance of a multidisciplinary team approach in the management of these patients cannot be overemphasised.

Aged↗
PubMed1991

Synthesis and expression in E. coli of the gene for human tumor necrosis factor (h alpha TNF).

A gene coding for human tumor necrosis factor (h alpha TNF) has been assembled by ligating short oligodeoxyribonucleotides and cloning into plasmid vectors. These oligonucleotides were prepared by the modified phosphoramidite methodology using isopropoxyacetyl (IPA) as a protecting group for exoamino- functions of nucleosides. Gene was expressed in E. coli and the protein product was purified to homogeneity by ion-exchange chromatography.

Amino Acid Sequence↗
PubMed1991

Expression of multivalent pre-S1 antigen of hepatitis B virus in Escherichia coli (synthetic oligodeoxynucleotides, surface antigens, recombinant DNA, fusion protein, beta-galactosidase).

The nucleotide sequence encoding 30 amino acids (aa) of the pre-S1 envelope region of the human hepatitis B virus has been constructed from twenty chemically synthesized oligodeoxynucleotides by simultaneous ligation. The DNA fragment containing four repeated sequences encoding the pre-S1 region (aa 20-49) has been inserted into the lacZ gene of the plasmid pWR450.1, yielding the recombinant pWX4 plasmid. The Escherichia coli DH5 strain transformed with pWX4 produces a beta-galactosidase-[-pre-S1(20-49) x 4] fusion protein. The hybrid protein containing 127 aa of repeated pre-S1 region has been isolated from Escherichia coli as inclusion bodies and purified by anion exchange chromatography. The antigenic properties of this fusion protein were confirmed by immunoblotting with pre-S1-specific monoclonal antibodies.

Amino Acid Sequence↗
PubMed1991

Separation of [Sp]-3'-O-(5'-dimethoxytritylthymidyl)-5'-O-(3'camphanoyl thymidyl)-O-methyl phosphite.

First isolation of diastereoisomerically enriched (d.p. 95%) [Sp]-3'-O-(5'-dimethoxytrityl tjymidyl)-5'-O-(3'-camphanoyl thymidyl)-O-methyl phosphite (1) allowed to assign, via sulfuration and deprotection, its absolute configuration as Sp. Its reactions with methyl iodide, dimethoxytrityl chloride, or water, respectively, allowed to confirm correctness of assignment of absolute configuration in diastereisomers of TPMeT, and to assign absolute configuration in corresponding diastereoisomers of TPDMTT and TPHT.

Chromatography, High Pressure Liquid↗
PubMed1990

Backbone-modified oligonucleotides containing a butanediol-1,3 moiety as a 'vicarious segment' for the deoxyribosyl moiety--synthesis and enzyme studies.

Sequential single replacement of nucleosides within the decanucleotide d[GGGAATTCCC] (7) by means of a butanediol-1,3 residue allowed us to obtain a set of ten decanucleotides containing 'vicarious' (V) carbon-phosphate fragments. These analogues were further used as substrates for svPDE, nuclease PI and EcoR1 endonuclease. Interestingly, replacement of any of the nucleosides within the canonical sequence ...GAATTC... by the butanediol-1,3 'vicarious' segment discriminates such constructs 8c-h as substrates for Eco-R1 enzyme.

Base Sequence↗
PubMed1990

Dam methyltransferase sites located within the loop region of the oligopurine-oligopyrimidine sequences capable of forming H-DNA are undermethylated in vivo.

Several derivatives of pUC18 plasmid were constructed that contained oligopurine-oligopyrimidine (pur-pyr) motifs surrounded by Dam methylation sites. Inserts of two of the molecules (pPP1 and pPP2) were able to adopt the triple-stranded conformation in vitro and show in vivo a remarkable undermethylation of specific sites when grown in JM105 dam+ strain. Mapping experiments revealed that undermethylated GATC sequences were located exclusively within the single-stranded loop region of the sequence involved in H-DNA formation. Control molecules which either contained the pur-pyr tracts (pPPK and pKK42) or not (pUC18) and were not able to form the triple-stranded conformation were found to be normally methylated by the dam gene product in vivo. Location of GATC within the triplex forming sequence seems to be a prerequisite for achieving its in vivo undermethylation. E.coli host factors are involved in the observed phenomenon. This has been deduced from the fact that the undermethylated state of pPP1 and pPP2 does not depend on the phase of growth of host cells and is steadily maintained up to 50 hours, whereas the kinetics of Dam methylation in vitro of sites located within the triplex loop does not differ substantially from the kinetics of methylation of other sites on the vector. Full methylation can be readily achieved in vitro. Additional factor(s) that operate in vivo to control the undermethylated state are most likely proteins since the observed effect can be suppressed by chloramphenicol administration to the cell cultures.

Base Sequence↗