Biomedical subjects

D Stoll

Publications and source records attributed to D Stoll.

At least 55 records · Page 3Linked to original sources

PubMed1997

[Hypoglosso-facial anastomosis: results and technical development towards end-to-side anastomosis with rerouting of the intra-temporal facial nerve (modified May technique)].

The authors report their experience with 31 hypoglosso-facial anastomoses mainly carried out after removal of tumours of the cerebello-pontine angle, 26 were available for evaluation: at 18 months there were 5 of grade II, 19 of grade IV and 2 of grade V. Only one patient was dissatisfied with the result. 24 of the patients had received their hypoglosso-facial anastomosis using the clinical technique of Korte. In 3 cases the operation was by the technique of May. The authors suggest a variation of May's technique: it was carried out on the last 4 patients. It consists of a hemi-hypoglosso-facial anastomosis with rerouting of the mastoid portion of the facial nerve, without using a nerve graft. The aim of this technique is to reduce the sequelae of hemi-lingual atrophy and paralysis (which gives trouble with articulation, mastication and deglutition). The authors' experience confirms that these sequelae are greatly reduced, if not abolished. The functional results in terms of facial movements were satisfactory and consistant: 43.7% were quantified--with 3 of grade II and one of grade IV on the House Brackmann scale.

Adolescent↗

PubMed1996

New ligands binding to the human leukocyte antigen class II molecule DRB1*0101 based on the activity pattern of an undecapeptide library.

Major histocompatibility complex (MHC) class II molecules present peptide antigens to CD(4+)-T cells. These heterogeneous peptides are derived from internalized exogenous proteins or from endogenous membrane proteins that are processed by the antigen-presenting cell. Peptides are bound to the MHC class II molecules in an extended conformation and extend out of the binding groove. The aim of this study was to estimate the influence of every amino acid in all the possible undecapeptide amides (2.048 x 10(14) individuals) on the binding to human MHC-DRB1*0101 molecules (HLA-DR1) and to identify new peptide ligands. 220 undecapeptide sublibraries, O/X10, each composed of ten degenerate positions and one defined position, were screened for binding to isolated HLA-DR1. Competition of the sublibraries with a fluorescence-labeled peptide ligand allowed definition of the amino acids favourable or unfavourable for DR1-binding at every sequence position. From the activity pattern of the undecapeptide library, 54 individual peptides were deduced (27 potential hits and 27 potential falls) and prepared by chemical synthesis. As anticipated, 27 positive and 27 negative results were obtained from the competition experiments. The 27 peptides that bind obey the rules for the HLA-DR1-binding motif. The synthetic peptide library approach proved to be valuable for the design of synthetic MHC class II ligands and thus can be considered as a basis for drug design in immunotherapy.

Amides↗

PubMed1996

Racemization of amino acids in solid-phase peptide synthesis investigated by capillary electrophoresis.

The rate of racemization during solid-phase peptide synthesis was studied using capillary electrophoresis and 18-crown-6 tetracarboxylic acid as chiral selector. For this purpose, the tripeptide D-Tyr-L-Lys-L-Trp as a model compound was synthesized by solid-phase peptide synthesis. A separation method based on capillary electrophoresis was developed which allowed all eight optical isomers of the tripeptide to be separated in a single run. The separation method was validated and was found to be well suited for purity analysis, with a limit of detection of 0.05% of the major compound. The method was revealed to be highly sensitive even to small variations in the buffer pH. Capillary electrophoresis was also employed to prove the enantiomeric purity of the Fmoc-protected amino acids used for peptide synthesis. A separation method based on micellar electrokinetic chromatography and gamma-cyclodextrin was developed for this purpose. The formation of optical isomers during peptide synthesis was investigated in the final product without hydrolyzing the tripeptide. This strategy allowed the rate of racemization to be determined by activation of amino acids in coupling cycles and cleavage of the peptides from the resin and from side-chain protecting groups. The formation of stereoisomers could be verified and was 0.4% or less per synthesis cycle. The experimental data agreed well with theoretical considerations, showing that racemization takes place mainly at the carboxy-activated amino acid during coupling.

Amino Acid Sequence↗

PubMed1996

Processing in the pestivirus E2-NS2 region: identification of proteins p7 and E2p7.

The pestivirus genome encodes a single polyprotein which is subject to co- and posttranslational processing by cellular and viral proteases. The map positions of all virus-encoded proteins are known with the exception of a hypothetical peptide (p?) which interlinks the glycoprotein E2 and the nonstructural protein NS2-3 approximately between amino acid positions 1060 and 1130. Expression studies with recombinant vaccinia viruses bearing a set of C-terminally truncated E2-p?-NS2-encoding sequences derived from a bovine viral diarrhea virus (BVDV) strain led to the identification of a minor fraction of E2 which had an increased molecular mass due to a C-terminal extension. This larger form of E2 (E2p7) was specifically recognized by an antiserum raised against the amino acid sequence from 1065 to 1125. In addition, the antibodies revealed a BVDV-encoded 7-kDa protein (p7) in infected cells. By radiosequencing it was determined that Val-1067 was the N-terminal amino acid of in vitro-synthesized p7. Analyses of BVDV and classical swine fever virus virions suggest that neither p7 nor E2p7 is a major structural constituent.

Amino Acid Sequence↗

PubMed1996

[Neuropeptides and nasal mucosa: a general review and update].

Following a review of the literature, the authors focused their interest on the sensitive physiology of the biochemistry of the nasal mucosa. After a general presentation of the neurotransmitter molecules studied (the tachykinins), the authors have determined their presence in the sensitive afferent nerves of the pituitary gland, evidencing their co-existence with various other neuropeptides. The distribution of these molecules was studied, given their capacity of acting on peripheral tissular receptors. The widespread distribution and the considerable potential of such neuropeptides reveal the important they play in nasal physiology.

Animals↗

PubMed1996

[Bacteriology of the nose and sinuses].

The authors, on the basis of 140 cases, analyze the bacterial flora of essentially chronic rhino-sinusitis observed in hospital consultations at the Pellegrin Hospital, the referral centre of the Aquitaine region. Samples taken in the operating theatre from 100 cases, by aspiration and mucosal biopsy, were studied in aerobic and anaerobic media. The results marked by the scarcity of sterile samples and of anaerobic germs, evidence the predominance of an aerobic flora, with in particular Haemophilus influenzae, Staphylococcus aureus and beta-hemolytic Streptococci. No significant difference was recorded between the bacteriology of acute sinusitis as against chronic sinusitis. The flora of sinusitis appear to depend more on the age factor than on the pathogenic type. Branhamella catharralis is present only in patients under 30. The enterobacteria appear in the adult 30-50 year-old age group and, as from the age of 50, are combined by Pseudomonas aeruginosa, which account for 18% of the strains. These two types of germs then appear to be predominant over the Staphylococci and the Haemophilus.

Adolescent↗

PubMed1995

[Complications of endonasal microsurgery].

Endonasal microsurgery, which has widely proved its efficacy, is not free of complications. They can be due to the technical act itself. In this case they result of surgery mistake and they induce an effraction of the operatory cavity walls. They can also be due to excessive healing of the nasal mucosa. Then they represent the real cause of failure in this type of surgery. The authors present their experience that they compare with similar cases of the literature.

Microsurgery↗

PubMed1995

[Nasal localization of a cicatricial pemphigoid: apropos of a case].

The authors reports the case of a 34 years old patient with a cicatricial pemphigoid whose diagnosis was made on a nasal symptomatology, isolated, persistent and with an increasing aggravation over the five last years. This auto-immune bullous disease is quite unusual and has got the trend of a synechia characteristic. The mucous membrane O.R.L. attacks are scarce not to say exceptional in their nasal aspect. The treatment based on Disulone has quickly allowed a progress over a trouble caused by the lesions but had to be interrupted for problems of tolerance.

Adult↗

PubMed1994

[Mucorales infection in diabetics].

Naso-orbito-cerebral mucormycosis is a fungal infection reported to occur especially in association with diabetes mellitus. Mucorales germinate in the nasal cavities and then colonize sinuses and the orbit. The diagnosis must be made before meningeal and cerebral impairement. The diagnosis is based on histologic and mucologic examination. Once the diagnosis is confirmed, treatment required high and prolonged dose of intravenous Amphotericine B, otherwise the evolution is fatal.

Adult↗

PubMed1993

Ethmoidal cancers: a retrospective study of 22 cases.

From April 1978 to June 1990, 22 patients with ethmoidal cancer were treated at Fondation Bergonié by a combination of surgery and radiation therapy. The mean age was 59.6 years (range 34-79 years) and the sex ratio is 2.7 (16 males/6 females). Histologic types were: adenocarcinoma, 13 cases; squamous carcinoma, 4 cases; undifferentiated carcinoma, 3 cases and esthesioneuroblastoma, 2 cases. Exposure to wood dust was encountered in 11 patients, especially in cases of adenocarcinoma: 10/13 (77%). Staging according to the classification of the University of Florida was: Stage I, 10 patients; Stage II, 5 patients and Stage III, 7 patients. Resection was considered as complete in 16 cases and only one orbital exenteration was performed. The postoperative radiation therapy delivered a mean given dose of 55.7 Gy (range 50-70 Gy) expressed to the hot spot using a technique adapted to tumor location and extension. Complete remission was achieved in 20 cases. Median follow-up is 28 months. The 5-year overall and disease-free survival are 44% and 38%, respectively. Analysis of recurrences according to staging gives: 5/10 Stage I, 2/5 Stage II and 5/7 Stage III. Recurrence is pejorative since death occurs in all cases within an average of 6 months following salvage treatment, except for three patients still alive within less than 6 months and in second remission. Prognosis of ethmoidal cancer depends on staging and local control.

Adenocarcinoma↗

PubMed1993

[Transfrontonasal approach: development of a mixed approach to ethmoid tumors. Experience of 12 cases].

Our experience in approaching ethmoid tumors through a combined pathway is currently based on 81 patients. 69 of them were malignant tumors treated by the neurosurgical subfrontal and paralateronasal transfacial rhinological approach. For the past two years, we have adopted the technical modification described in Bordeaux by Pinsolle and San-Galli enabling the approach of the ethmoid bone by means of a unique (Unterberger's scalp) incision and a unical frontonasal flap. 12 patients benefitted from this transfrontofacial access. The advantages and disadvantages of the technique are discussed.

Ethmoid Bone↗

PubMed1992

[Melanoma of the ORL mucosa].

The study of ENT mucous melanomas (ENT MM) was performed retrospectively, based on 20 patients treated in Bordeaux and 156 detailed files taken from the international literature. Each paragraph is followed by a review of the general literature. The ENT MM, a rare form of melanomas, presents a majority of nasal locations. The mean age is 63 years old. The sex ratio trend is towards one. The aspecific call signs partially explain the delayed diagnosis. The difficult pathological examination is assisted by tumoral markers. Mean survival is two and a half years without any clear prognostic factors as for cutaneous melanomas. Treatment is essentially surgical, but adjuvant radiotherapy may have a significant effect. The other treatments are palliative.

Aged↗

PubMed1991

[Role of radiotherapy in cancer of the ethmoid. Retrospective study of a series of 24 cases].

From april 1978 to december 1988, 24 patients were treated were by radiotherapy at the Bergonié Foundation cases were for ethmoidal cancer cases. Twenty two for initial treatment and two refermed for local recurrence. The mean age was 51.4 years and the sex ratio was 5.2 (21 men/4 women). Histologically there were 15 adenocarcinomas, 3 squamous carcinomas, 4 undifferentiated carcinomas and 2 esthesioneuroblastomas. According to the classification of the University of Florida, they were retrospectively classified as stage I = 9 pts, stage II = 5 and stage III = 10. Twenty one patients had postoperative radiotherapy and 3 had exclusive radiotherapy. The average dose was 55.3 Gy. Local control was obtained in 12 pts. Seven patients have recurred locally (within an average period of 12 months) and 5 patients showed progression of disease after treatment. The overall actuarial survival and the disease free survival at 5 years were respectively 50% and 53%. The actuarial survival by stage at 2 years and 5 years was: stage I (88% and 61%), stage II (100% and 50%), stage III (0%). The prognosis of ethmoidal cancer is strictly correlated to local control. For this reason, radiotherapy (with or without surgery) remains important in the treatment of this disease.

Adult↗

PubMed1991

Cyclic nucleotides differentially regulate the synthesis of tumour necrosis factor-alpha and interleukin-1 beta by human mononuclear cells.

Recent reports have shown that phosphodiesterase (PDE) inhibitors suppress production of tumour necrosis factor-alpha (TNF-alpha) in mouse macrophages. In the present study we show that theophylline, pentoxifylline and 3-isobutyl-1-methylxanthine markedly suppress the lipopolysaccharide (LPS)-induced synthesis of TNF-alpha (also) in human mononuclear cells. This effect is selective for TNF-alpha since up to several-fold higher concentrations of these PDE inhibitors do not affect production of interleukin-1 beta (IL-1 beta) in the same system. The observed effect of PDE inhibitors appears to be mediated by accumulation of cAMP since (i) addition of PDE inhibitors increases cAMP while cGMP levels are only marginally elevated; (ii) raising cAMP by another mechanism (enhanced formation induced by prostaglandin E2; PGE2) leads to a similar suppression of TNF-alpha production; and (iii) raising cGMP by activating the soluble guanylate cyclase by 3-morpholinosydnonimine (SIN 1) does not inhibit TNF-alpha synthesis. However, SIN 1 suppressed the synthesis of IL-1 beta. Selective suppression of TNF-alpha synthesis by PDE inhibitors may contribute to their beneficial effects in animal models of septic shock or lung injury and may thus have clinical implications.

Cell Line↗

PubMed1991

[Acute necrotizing sialometaplasia of the parotid gland].

Parotidean localization of acute necrotizing sialometaplasia is exceptional. Based on one observation, the authors evoke the diagnostic and physiopathological problems raised by this localization. The association of facial paralysis and a parotidean tumor make the case presented interesting, leading to exploratory surgery which can alone provide a diagnosis.

Acute Disease↗

PubMed1991

[Autonomic innervation of the vessels of the nasal mucosa: current concepts].

The nasal cycle enables the conditioning of air breathed in. It depends on the vascular vegetative innervation. Whilst its central diencephalic origin is probable, its mechanics remain mysterious. The involvement at the loco-regional level of short circuits ensuring the anatomical links between the vegetative, sensitive and cellular systems of the nasal mucosa is the basis of a new approach to chronic rhinological pathologies and certain facial algias.

Autonomic Nervous System↗

PubMed1990

[Sensitive innervation of the nasal mucosa: current concepts].

Sensitive innervation of the nasal fossae by the trigeminal nerves is not a simple passive system of information transmission, but also plays a considerable role in nasal physiology. An antidromic transmission mechanism is in fact added to the conventional centripetal transmission, leading to the release of neurotransmitters (P-substance and C.G.R.P.) at the level of the neuronasal nerve endings. These substances can cause inflammation and vasodilatation (sub-mucosal and perivascular) in certain sites of the 5th nerve, and stimulate the second parasympathetic neurone at the level of the sphenopalatine ganglion. Such phenomena, when they extend beyond physiology, can be the source of local pathology (rhinitis) or loco-regional pathology (headaches).

Animals↗

PubMed1990

[Radiotherapy of carcinoma of the nasopharynx].

Cancer of the cavum is a rare condition in France. These tumors have, however, a poor prognosis and in general occur in young subjects. While radiotherapy would appear to be the best mean of ensuring local control, life expectancy depends solely on distant metastases. Analysis of a series of 58 cases treated at the Fondation Bergonié from 1975 to 1985 demonstrated a 30% five year survival rate. Among the 25 cases of recurrence, 1 was exclusively local and 6 were loco-regional (T and N), while 18 patients presented metastatic progression, either exclusively, or with local or lymph node failure. The prognostic factors found in this series were: age, extension beyond the cavum, the dose of radiotherapy. Results in the literature in terms of survival remain poor, especially in advanced stages and the future perspectives for better control of this disease remain early diagnosis and other forms of therapy such as combined chemotherapy and radiotherapy.

Adolescent↗