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S Harbon

Publications and source records attributed to S Harbon.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Value of a scapular flap in the treatment of axillary hidradenitis. Apropos of a clinical case].

A severe case of axillary hidradenitis suppurativa, treated bilaterally by large excision followed by reconstruction with a pedicled scapular flap is presented. This reliable and thin fasciocutaneous flap provides good cover of large axillary defects with minimal donor site consequences. Its advantage is discussed versus the other surgical procedures used in this pathology for axillary reconstruction.

Adult↗
PubMed1990

Prostaglandins and muscarinic agonists induce cyclic AMP attenuation by two distinct mechanisms in the pregnant-rat myometrium. Interaction between cyclic AMP and Ca2+ signals.

In pregnant-rat myometrium (day 21 of gestation), isoprenaline-induced cyclic AMP accumulation, resulting from receptor-mediated activation of adenylate cyclase, was negatively regulated by prostaglandins [PGE2, PGF2 alpha; EC50 (concn. giving 50% of maximal response) = 2 nM] and by the muscarinic agonist carbachol (EC50 = 2 microM). PG-induced inhibition was prevented by pertussis-toxin treatment, supporting the idea that it was mediated by the inhibitory G-protein Gi through the inhibitory pathway of the adenylate cyclase. Both isoprenaline-induced stimulation and PG-evoked inhibition of cyclic AMP were insensitive to Ca2+ depletion. By contrast, carbachol-evoked attenuation of cyclic AMP accumulation was dependent on Ca2+ and was insensitive to pertussis toxin. The inhibitory effect of carbachol was mimicked by ionomycin. Indirect evidence was thus provided for the enhancement of cyclic AMP degradation by a Ca2(+)-dependent phosphodiesterase activity in the muscarinic-mediated effect. The attenuation of cyclic AMP elicited by carbachol coincided with carbachol-stimulated inositol phosphate (InsP3, InsP2 and InsP) generation, which displayed an almost identical EC50 (3 microM) and was similarly unaffected by pertussis toxin. Both carbachol effects were reproduced by oxotremorine, whereas pilocarpine (a partial muscarinic agonist) failed to induce any decrease in cyclic AMP accumulation and concurrently was unable to stimulate the generation of inositol phosphates. These data support our proposal for a carbachol-mediated enhancement of a Ca2(+)-dependent phosphodiesterase activity, compatible with the rises in Ca2+ associated with muscarinic-induced increased generation of inositol phosphates. They further illustrate that a cross-talk between the two major transmembrane signalling systems contributed to an ultimate decrease in cyclic AMP in the pregnant-rat myometrium near term.

1-Methyl-3-isobutylxanthine↗
PubMed1990

[Malherbe's calcified epithelioma. Review of 80 cases].

The authors review a series of 80 Benign Calcifying Epitheliomas (BCE), and describe their main clinical, histologic and prognostic features, in comparison with those reported in the literature. BCE or pilomatrixoma arises from the hair matrix, and represents approximately 1/1,000 of all skin tumors. Statistically, it is found more frequently among children under the age of 10 years and anatomic locations are mostly located on the face and upper limb. These benign tumors tend to develop slowly in subcutaneous tissue, and their treatment consists of simple surgical excision, except in some instances, where signs of more aggressive behavior can be found.

Adolescent↗
PubMed1990

["Chinese hat" flap].

A design of a new type of advancement flap is described and called "chinese hat" flap. It uses the properties of the traditional advancement flap combined with rotation at the two distal edges, that overlap the height of the defect like two claws. This allows direct suture for larger defects with a prominent dog ear that become level with time. Two cases illustrate the procedure.

Face↗
PubMed1990

[Nasal reconstruction: a comparative study between the Converse scalping flap and expanded median forehead flap].

The authors, reviewing a series of 16 at least subtotal nasal reconstructions over the past 4 years, discuss the respective advantages of the two methods, which both give good results for this purpose. Nowadays, the balance favors expansion despite its duration and complexity for the very significant aesthetic benefits in terms of forehead scarring. The guidelines concerning this technique employed in 6 cases are described and reviewed in detail. Nevertheless, the Converse scalping flap remains a simple and quick solution especially after cancer resection in the elderly; some details seem important to diminish its sequelae.

Basal Cell Carcinoma↗
PubMed1990

Pharmacological evidence for distinct muscarinic receptor subtypes coupled to the inhibition of adenylate cyclase and to the increased generation of inositol phosphates in the guinea pig myometrium.

In the guinea pig myometrium, muscarinic receptor activation leads to contraction and elicits two biochemical responses viz. an increased formation of inositol phosphates (via a guanine nucleotide regulatory protein, distinct from the stimulatory and inhibitory G proteins of the adenylate cyclase system and a decreased synthesis of cyclic AMP involving inhibitory G protein activation. We now describe two major differences in the effects of muscarinic agonists. First, the greater potency of carbachol in inhibiting cyclic AMP formation (EC50 = 8 nM) than in stimulating the accumulation of inositol phosphates and tension (EC50 = 15 and 2 microM, respectively). Second, carbachol, oxotremorine and pilocarpine were equally effective in eliciting cyclic AMP inhibition but the order of potency for inositol phosphate formation was carbachol greater than oxotremorine and pilocarpine was without effect. The partial agonists, pilocarpine and oxotremorine, inhibited carbachol-mediated inositol phosphate formation. Pirenzepine, selective for muscarinic M1 receptor subtype, displayed a low affinity for antagonizing cyclic AMP inhibition, inositol phosphate generation and tension due to carbachol (Ki = 286, 92 and 110 nM, respectively). AF-DX116 (11-[( 2-[(diethylamino)methyl]-1- piperidinyl]acetyl)-5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepine- 6-one), selective for cardiac M2 receptors blocked cyclic AMP inhibition with high affinity (Ki = 1.14 nM) while it antagonized inositol phosphate formation with low affinity (Ki = 346 nM). Both high (Ki = 1 nM) and low (Ki = 100 nM) affinities were displayed by AF-DX116 in antagonizing contractions due to carbachol (24 and 76% inhibition, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclase Inhibitors↗
PubMed1989

Identification of both Gi2 and a novel, immunologically distinct, form of Go in rat myometrial membranes.

Immunoblotting of rat myometrial membranes with an antiserum (SG1) which recognizes the alpha-subunits of both Gi1 and Gi2 indicated the presence of detectable levels of an apparently single form of some 40 kDa. A second antiserum (LE2) specific for Gi2 also recognized this protein, confirming its identity. Immunoblotting of the myometrial membranes with a series of antipeptide (OC1, IM1, ON1) and polyclonal (RV3) antisera, all of which recognize rat brain Go, produced a more complex pattern. Antisera OC1 and ON1 recognized a single polypeptide which essentially comigrated with rat brain Go. In contrast, antisera RV3 and IM1 did not recognize the myometrial protein. These data provide evidence for the presence of Gi2 and of a novel G-protein, related immunologically to Go, in rat myometrial membranes.

Animals↗
PubMed1989

[Malignant eccrine poroma. Apropos of 2 facial sites].

The authors report 2 cases of malignant eccrine poroma (M.E.P.) located on the face: one on the auricle which was treated by triangular shape resection, the other on the nasal tip which underwent a reconstruction with a Converse scalping flap after large surgical resection removed underlying skin and cartilages. A study reviewing the main features of M.E.P. is presented on the basis of these clinical cases. M.E.P. are skin appendage tumors originating from the intra epithelial portion of the eccrine sweat duct. Such denominations as malignant hidroancanthoma, eccrine porocarcinoma, poroepithelioma, correspond to the same tumor. They are very rare: 73 cases have been reported in the world literature with only 12 located on the face; the main localisations involve the lower extremities, but the palmo plantar areas are involved more frequently in benign tumors. Elderly people over 60 are concerned in almost all cases. Many of the patients have noticed a lesion for years before a diagnosis was made suggesting one of the etiopathogenic theories that M.E.P. may result from malignant transformation of a benign eccrine poroma. Their clinical appearance is non specific nevertheless their malignant nature is suspected and misdiagnosis with basal cell carcinoma is frequent. Microscopic findings demonstrate the diagnosis by showing the association of malignant features with eccrine poroma. These tumours invade both by superficial spead and by deep extension towards dermal and hypodermal structures. Their prognosis is marked by the rapid development, in approximately on half of cases, of cutaneous, lymp node and visceral metastases. Clinical and histological examination have no prognostic value exception the case of deep invasion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma, Sweat Gland↗
PubMed1989

[Giant sacrococcygeal teratoma in adults].

Sacro-coccygeal teratomas (SCT) are rare congenital tumors (1/40,000 births) but the commonest neoplasms in the newborn, generally discovered at birth; they are well known by pediatric surgeons who operate on them during the first days of life because of the high risk of malignant transformation when the diagnosis is delayed after several months of life. Exceptionally these tumors are observed in the adult without being diagnosed during infancy. The case of a 67 year old man is reported; the tumor presented as a solid mass complicated by necrosis and ulceration. The operation involved en bloc resection of the tumor and its sacro-coccygeal bony attaches. The tumor was found to be benign on histological examination. The main problems concerning diagnosis are discussed: possible association with meningocele and intra-pelvic extensions; these two factors must be defined preoperatively as they may change the approach to treatment. TSC can only be treated surgically, and the classical inverted V incision performed with the patient in the prone position is discussed versus other procedures designed a midline sacral scar, including Z plasty. Radical resection of the tumor with its pedunculated last two sacral and coccygeal vertebrae must be performed to avoid recurrence that may be malignant even if the primary lesion was benign.

Aged↗
PubMed1989

[Augmentation rhinoplasty using bone graft. Technical aspects and therapeutic deductions].

Reviewing 45 cases of augmentation rhinoplasties with bone grafting the authors discuss some technical points and the choices of their indications: donor site, incision, patterns of graft implantation depending on clinical examination which selected the cases where exogenous material from the nose is needed for reconstruction. A columellar support seem to them necessary to correct collapsed noses and in these cases a mortise and tenon joint has been employed. When a pure saddle nose deformity exists, a biomaterial can be used reducing morbidity of an iliac bone graft.

Bone Transplantation↗
PubMed1989

[Therapeutic measure in the repair of traumatic loss of substance of the scalp].

Repair of scalp tissue losses must reach two ends: Cover cranium and its contain while restoring hair. Only scalp flaps can attain these aims, but their disadvantage is most of the time to shift alopecia. For the major tissue losses, since skin expansion, treatment proceedings have changed: an immediate and temporary cover by a skin graft can be proposed, instead of multiple scalp flaps or free flaps. Few cases illustrate this alternative allowing discussion about their respective indications.

Aged↗
PubMed1989

[Expansion prostheses in restorative and esthetic surgery of the head].

The authors discuss the results of 29 cases of tissue expansion, using 40 expanders, at the head and neck level, in an attempt to achieve a constructive self-criticism. The results have been classified into excellent (18 over 28 cases), good (4/29), fair (3/29) and poor (4/29). Complications were those usually reported: pain, infection, wound dehiscence, reservoir failure. In summary, 23 of 29 patients have definitely gained from tissue expansion. The remaining 6 cases considered as failures are carefully discussed leading to some practical conclusions.

Adolescent↗
PubMed1989

[Esthetic refinements in cheiloplasty or the use of the V, W, X, Y, Z technics].

Classically, V-wedge excision of the lip allows direct closure of defects less than a third of its width. But undue tension may cause dehiscence of the suture lines responsible of narrowing of the mouth and excessive scarring especially on the external mucosa. To avoid these aesthetic complications modified incision should be made: W followed by a V-Y advancement closure, completed by a Z plasty on the vermilion.

Cicatrix↗
PubMed1988

Fluoroaluminates mimic muscarinic- and oxytocin-receptor-mediated generation of inositol phosphates and contraction in the intact guinea-pig myometrium. Role for a pertussis/cholera-toxin-insensitive G protein.

1. In the intact guinea-pig myometrium, carbachol and oxytocin stimulated a specific receptor-mediated phospholipase C activation, catalysing the breakdown of PtdIns(4,5)P2 with the sequential generation of InsP3, InsP2 and InsP. Stimulation of muscarinic receptors also triggered an inhibition of cyclic AMP accumulation caused by prostacyclin. 2. NaF plus AlCl3 mimicked the effects of carbachol and oxytocin by inducing, in a dose-dependent manner, the generation of all three inositol phosphates as well as uterine contractions. AlCl3 enhanced the fluoride effect, supporting the concept that A1F4- was the active species. Under similar conditions, fluoroaluminates activated the guanine nucleotide regulatory protein Gi, reproducing the inhibitory effect of carbachol on cyclic AMP concentrations. 3. Both carbachol- and oxytocin-mediated increases in inositol phosphates, as well as contractions, were insensitive to pertussis toxin, under conditions where the expression of Gi was totally prevented. Cholera toxin, which activates Gs and enhances cyclic AMP accumulation, failed to affect basal or oxytocin-evoked inositol phosphate generation, but induced a slight, though consistent, attenuation of the muscarinic inositol phosphate response, which was similarly evoked by forskolin. 4. The data provide evidence that, in the myometrium, (a) a G protein mediates the generation of inositol phosphates and the Ca2+-dependent contractile event, (b) the relevant G protein that most probably couples muscarinic and oxytocin receptors to phospholipase C is different from Gi and Gs, the proteins that couple receptors to adenylate cyclase, and (c) cyclic AMP does not seem to control the phosphoinositide cycle, but rather exerts a negative regulation at the muscarinic-receptor level.

Adenylate Cyclase Toxin↗
PubMed1988

Forskolin alters sensitivity of the cAMP-generating system to stimulatory as well as to inhibitory agonists. A study with intact human platelets and guinea pig myometrium.

1. In both the intact guinea pig myometrium and human platelets, cAMP accumulation was enhanced by prostaglandin I2 (prostacyclin, PGI2) and forskolin with potentiated responses in the simultaneous presence of both effectors. Under basal conditions, forskolin caused rises in platelet cAMP concentration through a single low-affinity interaction (Kapp = 90 microM) while in myometrium, activation involved both a low-affinity (Kapp = 10 microM) and a high-affinity (Kapp = 0.8 microM) component. The contribution of the high-affinity component could be reduced when endogenous PGI2 was decreased. In both tissues, the synergistic effect of forskolin in the presence of PGI2 was mediated by a single high-affinity interaction (Kapp = 0.3 microM). The data were consistent with a low-affinity interaction of the diterpene with the cyclase catalytic unit C generating the C...forskolin state and with a high-affinity interaction of the diterpene with the activated complex (stimulatory regulatory protein) and C generating the potentiated Gs-C...forskolin state. 2. Both norepinephrine in platelets and carbachol in the myometrium (via Gi, the inhibitory regulatory protein) inhibited PGI2-mediated cAMP accumulation (EC50 = 100 nM and 8 nM respectively). The persistently activated cAMP-generating system induced by cholera toxin in the myometrium was also susceptible to inhibition but the EC50 for carbachol was increased to 50 nM and the extent of inhibition was decreased. Forskolin-mediated effect in platelets was inhibited by norepinephrine as was the PGI2 response. By contrast, the synergistic state of the cyclase resisted the inhibitory action of norepinephrine and carbachol in platelets and myometrium respectively. In the myometrium, where the cAMP response due to forskolin alone partially involved some synergistic Gs-C ... forskolin species, carbachol at 50 microM elicited no more than 30% inhibition. Inhibition was partly improved (60% inhibition at 1 microM carbachol) when the contribution of the Gs-C species was decreased by lowering the concentration of local PGI2. Partial inhibition by norepinephrine was similarly observed in platelets under partial synergistic conditions. The data suggest that receptor-mediated inhibition of cAMP generation could be differentially expressed depending on the nature of the active species of the cyclase involved in the stimulatory responses.

Animals↗
PubMed1988

[Possibilities of the use of the Converse scalp flap in maxillofacial surgery. Review of 13 cases].

13 Converse scalping flaps have been done in the past 3 years. 11 cases were for nasal reconstruction, at least half nose which is its main indication including 4 after gun shot wounds and 7 for invasive skin cancers. The preference of this flap is discussed versus the other processes for reconstruction: median forehead flap whatever its design, Washio or orther fronto-auricular flaps, free flaps. Lining and framework repair are done in the same operation than cover when usefull. 2 other clinical cases illustrate other areas than nose where the Converse flap can be employed.

Female↗
PubMed1987

[SIN-1 interactions with the generation of cyclic nucleotides and arachidonate oxide metabolites in the uterine muscle].

In the uterine smooth muscle, SIN-1 stimulated cGMP accumulation independently of the presence of Ca2+ and activated the soluble form of guanylate-cyclase through mechanisms apparently similar to those involved in the stimulations evoked by NO-containing compounds. These activations appear different from those induced by hydroperoxy-unsaturated fatty acids and which contribute to the carbachol-mediated cGMP accumulation. SIN-1 did not influence the rise in cAMP of the biosynthesis of PG1(2) and 12-HETE due to exogenous arachidonic acid. By contrast, SIN-1 markedly inhibited the increased synthesis of PG1(2) induced by the ionophore A23187 which was due to a prior, Ca2+-dependent, liberation of endogenous arachidonic acid. The data suggests an interference of SIN-1 with the generation and/or the expression of the Ca2+ signal.

Animals↗