Ischemic proctitis following Delorme procedure for external rectal prolapse.
Explore the source record for details and available documents.
Aged↗
Biomedical subjects
N Osman
Publications and source records attributed to N Osman.
[A new complication of contraceptive hormonal implant: about two cases of lesions of the ulnar nerve at the arm level].
The authors refer 2 cases of iatrogenic lesions of the ulnar nerve at the arm level after insertion of contraceptive hormonal implants. The presence of a small under-skinned pannicula of fat on the internal side of the arm of slim women exposes the ulnar nerve during the insertion of the implant or its withdrawal. Therefore we advise the insertion of such implants on medial side of thigh in slim women. We equally recommend that withdrawal of non-tangible devices implanted on the medial side of the arm or in case of neurologic trouble, even transitory, be done by a trained microsurgeon.
Adult↗
[The VB system: a new modular osteosynthesis material involving both screws and wires].
VB is an osteosynthesis system for the stabilisation of small fragments, which combines the benefits of both wires and screws. It is a modular system comprising a threaded pin and a ring. The threaded pin is first positioned. Then a ring is grasped and opened by the progressive angulation of a screwdriver. Still anchored on the screwdriver, the ring slides easily on the pin. It is clamped on the pin by simply removing the screwdriver and the pin is then cut. This modular system includes 1.8 and 1.1 mm pins and different types of rings (threaded or non threaded, with or without collars). The system is easy to handle and can be introduced using an open or percutaneous technique, allowing compression or distraction. Our preliminary series, performed in accordance with National clinical trial protocol (Huriet) consisted of 50 cases in 24 patients (five women and 19 men) with an average age of 48 years, and a follow-up of more than six months. Fourteen cases of fractures (28 implants) were treated as emergencies (two radial heads, one capitellum, one trochlea of the humerus, seven distal radius fractures, one trapezium, two metacarpals) and 12 cases (22 implants) were elective cases: arthrodesis (one trapezo-metacarpal, one intermetacarpal, two interphalangeal, two carpal), non-union (six scaphoids, one phalangeal) and one phalangeal malunion. Hardware removal was performed in 16 cases. No implant failure has been detected. One case, a DIP arthrodesis, had a suspicion of sepsis which led to the removal of the implants at six weeks. The results of this study have convinced us of the merits of the system, which combines the advantages of both wires and screws. The system allows the user to perform either distraction or compression, and to adjust the force by hand. Compared to the fixed amount of compression produced by lag screws, this feature seems to be a real step forward.
Adult↗
Human chorionic gonadotrophin is an endothelium-independent inhibitor of rat aortic smooth muscle contractility.
The study tested the hypothesis that human chorionic gonadotrophin (hCG) attenuates isolated vascular smooth muscle contractility and investigated the role of the vascular endothelium in hCG-induced altered responses of vascular smooth muscle. The contractile responses of isolated aortic rings from normal, hCG-treated, and estrogen-treated female virgin Wistar rats to phenylephrine, angiotensin II, KCl, and CaCl2 were compared. The effect of pretreatment with N-monomethyl-L-arginine (L-NMMA), methylene blue, indomethacin, calcium-free medium, and de-endothelialization on responses to phenylephrine of aortic rings from control and hCG-treated rats were also examined. Intraperitoneal administration of hCG caused attenuation of contractile responses of isolated aortic rings to all agents. The attenuated responses to phenylephrine were not reversed by de-endothelialization, or pretreatment of the rings with L-NMMA, methylene blue, or indomethacin. It was concluded that hCG attenuates vascular smooth muscle contractility. The effect is independent of the vascular endothelium, not agonist-specific, and appears to involve alterations of calcium availability.
Angiotensin II↗
Measurement-specific quality-of-life satisfaction during the menopause in an Arabian Gulf country.
OBJECTIVE: The aim of this study was to use an instrument, the menopause-specific quality-of-life satisfaction questionnaire for the postmenopausal period, in the United Arab Emirates (UAE). DESIGN: A cross-sectional descriptive study was used to generate menopause symptoms experienced by Arabian Gulf women. Measurement-specific quality-of-life satisfaction questionnaires were used and face-to-face interviews were performed. SETTING: The study was based in primary health-care clinics in Al Ain City, Sharjah and Dubai Emirates, UAE. SUBJECTS: A multistage sampling design was used, and a representative sample of 450 UAE females aged 45 years and above were included during January-April 1999. RESULTS: Of the 450 women living in both urban and rural areas, 390 women agreed to participate (86.7%) and responded to the study. The mean age and standard deviation (SD) of the subjects was 56.5 +/- 6.6 years, and the median age of natural menopause in the present study was 48 years (mean +/- SD 48.4 +/- 3.8). The rate of consanguinous marriages in the sample was found to be 47.2%. The most common disease was found to be diabetes mellitus (10.3%), followed by osteoarthritis (7.7%), hypertension (7.2%) and asthma (6.2%), but the majority of subjects (68.7%) had no specific disease. Out of 29 possible symptoms, the mean number of symptoms was 7.57 (range 0-24). The most frequent symptom was 'aches in the back of the neck or head' at 46.4% followed by 'aches in the muscles/joints' at 34.6%. The least reported symptom was 'facial hair' at 15.9%. Increasing education resulted in more symptoms reported, and increasing parity resulted in fewer symptoms reported. In the present study, it was found that employed women experienced more symptoms and disorders. Of the total sample, 28.5% of the subjects reported no symptoms. In the four domains, 69% reported physical symptoms, 58.7% reported psychosocial symptoms, 40% reported vasomotor symptoms and 37.9% reported sexual symptoms. Spearman's rank correlation coefficient indicated that there is highly statistically significant concordance between the four domains (p < 0.01). CONCLUSION: The present study showed that menopause-related symptoms in UAE women are fewer and of less severity than in Western women. The postmenopausal women, despite a continued decline in estrogen levels, reported few symptoms as part of a normal life stage, suggesting that they were able to cope with stress.
Asthma↗
[Lesions of the radial nerve in fractures of the humeral diaphysis. Apropos of 62 cases].
PURPOSE OF THE STUDY: Evaluate outcome of different techniques used for radial nerve repair after humeral shaft fractures. Identify situations where nerve exploration is required or inversely unneeded. Evaluate the risk of more systematic nerve exploration in case of radial nerve palsy. MATERIAL AND METHODS: Over a 10 year period, we cared for 62 patients with humeral fractures associated with radial nerve palsy who were addressed directly to our unit or referred after prior care. There were 54 men (mean age 30 years, 17 - 66) and 8 women (mean age 40 years, 19 - 80). There were 40 fractures of the mid-third and 22 fractures of the distal third of the humerus. Anatomic severity varied although most fractures were displaced or subsequent to high-energy trauma. Orthopedic treatment was used alone in 14 cases. There were 6 plate fixations and 42 intramedullary nailings. Twenty-four of the 62 cases of radial nerve palsy resulted from nerve tears but a continuous nerve was found in 38 cases. Tears were treated by primary suture (n =4), secondary graft (n =17, 5 with 2 torons and 12 with 3 or 4 torons), or primary muscle transfer (n =3). Neurolysis was used in 6 of the 38 cases with continuous nerve. Motor outcome was assessed using composite criteria taking into account the physiological role of each muscle group. RESULTS: All primary sutures gave excellent results. Excellent or good outcome was achieved in 12 of the 17 secondary grafts although a complementary transfer was required in 2 cases. Conversely, outcome was average in 2 cases and a failure in 3. Outcome depended on the length of the graft and the number of torons used. The importance of a proximal resection in healthy tissue sometimes required a complementary medial access and a graft between the biceps and the brachialis. Recovery was achieved in 37 of the 38 lesions with continuous nerve including 31 cases which did not require a second procedure. DISCUSSION: In case of nerve rupture, the outcome of primary suture appears to be better than that of secondary grafts. The success of the graft depends on the length of the tissue loss after sectioning in healthy tissue and on the number of torons used. This difference in prognosis points out the usefulness of systematic exploration in order to use primary or early direct suture in cases of high-energy displaced fractures. Minimally displaced fractures often are accompanied by a simple contusion with spontaneous recovery. However, in intermediary cases, the decision to make a systematic nerve exploration during the osteosynthesis procedure (aimed at early mobilization) is based on the fact that recovery was achieved in 23 cases in which initial exploration of a continuous nerve has been performed. Indirectly, the favorable outcome of postoperative paralyses reported by several authors, also supports this policy.
Adolescent↗
Histomorphometry of the ulnar nerve and of its branches.
A morphometric study has shown that 10% of the fibers of the ulnar nerve should suffice to reinnervate the biceps muscle in brachial plexus palsies. The aim of this study was to evaluate, by a morphometric study using computerized microanalysis, the cross-sectional surface areas of the different collateral and terminal branches of the ulnar nerve. This was expressed in terms of percentage of the cross-sectional surface area of the main trunk of the ulnar nerve. The study revealed that the branch to the flexor digitorum profundus bellies to the ring and little fingers formed 9.5% of the cross-sectional area of the ulnar nerve. Thus use of these fascicles destined for the flexor digitorum profundus, identified by intra-operative nerve stimulation, at the level of the arm would be sufficient for neurotisation of the nerve to the biceps. This has been confirmed by the initial clinical results in patients operated upon using this technique.
Aged↗
The effect of sodium based hypo-osmolality on arterial smooth muscle reactivity in vitro.
The study tested the hypothesis that the reduced [Na+]e and hypo-osmolality of normal pregnancy are causally linked to the attenuation of vascular smooth muscle reactivity in vitro. Aortic rings from nonpregnant female rats were incubated in physiological medium containing 114 mM NaCl/l and the contractile responses to phenylephrine, KCl and CaCl2 as well as the relaxations to acetylcholine and KCl were compared with those of rings incubated in normal medium containing 119 mM NaCl/l. There was no solute substituted for the lowered [Na+]. Experiments with phenylephrine were repeated using de-endothelialized rings and intact rings pretreated with indomethacin. Contractile responses of intact rings (n = 11) in hypo-osmolar solution to phenylephrine were significantly (P < 0.001) lower than of those in normal medium (n = 11). Responses were partially restored by endothelial denudation but not in the presence of indomethacin. Relaxations to acetylcholine (n = 7 for hypo-osmolar; n = 6 for normal solution) and KCl (n = 7 for each of hypo- and normal osmolar) were significantly enhanced (P < 0.05) in rings incubated in hypo-osmolar solution. There was no significant difference between the responses of the rings to KCl, and CaCl2 in either solution. These effects are similar to some of those previously described for vascular smooth muscle in normal pregnancy suggesting that the reduced [Na+]e and hypo-osmolarity of normal pregnancy may be contributing to the diminished vascular reactivity.
Acetylcholine↗
Results of non-operative and operative treatment of humeral shaft fractures. A series of 104 cases.
The aim of this study was to examine the results of different modalities applied in the treatment of 104 fresh diaphyseal fractures of the adult humerus treated in the department between January 1994 and March 1997. These results were classified according to the criteria described by Stewart and Hundley. 32 patients (30.8%) were treated non-operatively using a sling and a moulded plaster splint. The type of treatment had to be changed in 12 of these patients due to 14 different complications that occurred during the course of non-operative treatment. Thus, 20 patients (62.5%) underwent non-operative treatment until fracture-union. The results in this group were: very good in 12 cases (60%), good in 5 cases (25%), fair in 3 cases (15%). 28 fractures were treated using plates and screws. 4 events (14%) occurred during in the post-operative period and, apart from 2 cases of non-union, the overall result in the 26 patients in whom the fracture united was: very good in 23 cases (88.5%) and good in 3 cases (11.5%). 22 patients (21.1%) underwent fixation using multiple flexible intramedullary wires via a supracondylar approach. Apart from one case of non-union, the final result in the 21 patients in whom the fracture united was: very good in 9 cases (42.8%), good in 9 cases (42.8%), fair in 2 cases (9.5%) and poor in 1 case (4.9%). 22 fractures were treated using an intramedullary Seidel nail. The final result in these patients was: very good in 11 cases (50%), good in 9 cases (41%) and poor in 2 cases (9%). The indications for treatment should be eclectic. Non-operative treatment remains the method of choice for undisplaced or minimally-displaced fractures or comminuted fractures with multiple parallel longitudinal fracture-lines over the middle-third, while surgical treatment is considered for displaced fractures and essentially depends upon the type and level of the fracture. Transverse and short oblique fractures are treated using a plate or a Seidel nail. Fractures with a third fragment require plate osteosynthesis. Multiple flexible intramedullary wires are used for segmental fractures or for diaphyseal fractures associated with fractures of the neck of the humerus. Comminuted fractures are realigned using an intramedullary Seidel nail or multiple flexible wires. As far as the site of fracture is concerned, those of the proximal and middle thirds of the humerus are well treated using an intramedullary nail or multiple wires or with a plate, while plating is most often the method of choice for fractures of the distal-third.
Adolescent↗
Calcium supplementation is associated with endothelium dependent attenuation of vascular smooth muscle reactivity in normotensive pregnant and nonpregnant rats.
The study tests the hypothesis that the blood pressure lowering effect of a high calcium diet is mediated through attenuation of vascular reactivity and examined the mechanisms involved in both normotensive pregnant and nonpregnant rats. The contractile responses of aortic rings of Wistar rats fed on high (1.7%, 2.1%) and normal (0.9%) calcium diets to phenylephrine, angiotensin II, KCl, and CaCl2 were studied. The relaxations to acetylcholine and potassium chloride, as well as the effects of endothelial denudation, pretreatment with indomethacin (10[-6] mol/L), methylene blue (10[-6] mol/L), and calcium free solution on the responses to phenylephrine were also examined. In both pregnant and nonpregnant rats, the contractile responses of aortic rings of animals fed a high calcium diet to all the agents were significantly attenuated, compared with those of controls. After endothelial denudation, or treatment with methylene blue, but not with indomethacin, the responses of the rings to phenylephrine were enhanced and not different from similarly treated rings from rats on a normal calcium diet. There was no difference in the contractile responses to phenylpehrine in calcium free solution. The relaxation to acetylcholine, but not to potassium chloride, was enhanced in rings from rats on a high calcium diet. The diminution in reactivity was not associated with corresponding changes in sensitivity of the tissues. It is concluded that in normotensive rats a high calcium diet is associated with diminished vascular smooth muscle reactivity that is endothelium dependent, and involves increased stimulation of the nitric oxide-guanylate cyclase pathway but not of the sodium-potassium ATPase or prostacyclin.
Angiotensin II↗
Combined transgenic expression of alpha-galactosidase and alpha1,2-fucosyltransferase leads to optimal reduction in the major xenoepitope Galalpha(1,3)Gal.
Hyperacute rejection of pig organs by humans involves the interaction of Galalpha(1,3)Gal with antibodies and complement. Strategies to reduce the amount of xenoantigen Galalpha(1,3)Gal were investigated by overexpression of human lysosomal alpha-galactosidase in cultured porcine cells and transgenic mice. The overexpression of human alpha-galactosidase in cultured porcine endothelial cells and COS cells resulted in a 30-fold reduction of cell surface Galalpha(1,3)Gal and a 10-fold reduction in cell reactivity with natural human antibodies. Splenocytes from transgenic mice overexpressing human alpha-galactosidase showed only a 15-25% reduction in binding to natural human anti-Galalpha(1,3)Gal antibodies; however, this decrease was functionally significant as demonstrated by reduced susceptibility to human antibody-mediated lysis. However, because there is residual Galalpha(1,3)Gal and degalactosylation results in the exposure of N-acetyllactosamine residues and potential new xenoepitopes, using alpha-galactosidase alone is unlikely to overcome hyperacute rejection. We previously reported that mice overexpressing human alpha1,2-fucosyltransferase as a transgene had approximately 90% reduced Galalpha(1,3)Gal levels due to masking of the xenoantigen by fucosylation; we evaluated the effect of overexpressing alpha-galactosidase and alpha1,2-fucosyltransferase on Galalpha(1,3)Gal levels. Galalpha(1, 3)Gal-positive COS cells expressing alpha1,3-galactosyltransferase, alpha1,2-fucosyltransferase, and alpha-galactosidase showed negligible cell surface staining and were not susceptible to lysis by human serum containing antibody and complement. Thus, alpha1, 2-fucosyltransferase and alpha-galactosidase effectively reduced the expression of Galalpha(1,3)Gal on the cell surface and could be used to produce transgenic pigs with negligible levels of cell surface Galalpha(1,3)Gal, thereby having no reactivity with human serum and improving graft survival.
Animals↗
Transgenic approaches for the reduction of Galalpha(1,3)Gal for xenotransplantation.
The major barrier to clinically successful xenotransplantation is the lack of effective therapies aimed at eliminating antibody and complement -dependent hyperacute rejection. This review examines transgenic strategies to eliminate or reduce expression of the major pig to human xenoantigen Galalpha(1,3)Gal such that the epitope is no longer recognized by natural human antibodies, by the use of glycosidases and/or glycosyltransferases that can competitively and effectively inhibit the activity of the alpha1,3galactosyltransferase gene and thereby eliminate the xenoantigen Galalpha(1,3)Gal.
Animals↗
Switching amino-terminal cytoplasmic domains of alpha(1,2)fucosyltransferase and alpha(1,3)galactosyltransferase alters the expression of H substance and Galalpha(1,3)Gal.
When alpha(1,2)fucosyltransferase cDNA is expressed in cells that normally express large amounts of the terminal carbohydrate Galalpha(1,3)Gal, and therefore the alpha(1,3)galactosyltransferase (GT), the Galalpha(1,3)Gal almost disappears, indicating that the presence of the alpha(1,2)fucosyltransferase (HT) gene/enzyme alters the synthesis of Galalpha(1,3)Gal. A possible mechanism to account for these findings is enzyme location within the Golgi apparatus. We examined the effect of Golgi localization by exchanging the cytoplasmic tails of HT and GT; if Golgi targeting signals are contained within the cytoplasmic tail sequences of these enzymes then a "tail switch" would permit GT first access to the substrate and thereby reverse the observed dominance of HT. Two chimeric glycosyltransferase proteins were constructed and compared with the normal glycosyltransferases after transfection into COS cells. The chimeric enzymes showed Km values and cell surface carbohydrate expression comparable with normal glycosyltransferases. Co-expression of the two chimeric glycosyltransferases resulted in cell surface expression of Galalpha(1,3)Gal, and virtually no HT product was expressed. Thus the cytoplasmic tail of HT determines the temporal order of action, and therefore dominance, of these two enzymes.
Animals↗
The protein interactions of the immunoglobulin receptor family tyrosine-based activation motifs present in the T cell receptor zeta subunits and the CD3 gamma, delta and epsilon chains.
Immunoglobulin family tyrosine-based activation motifs (ITAM), which define the conserved signaling sequence EX2YX2L/IX7YX2L/I, couple the T cell antigen receptor (TCR) to cellular proteins including protein tyrosine kinases (PTK) and adapter molecules. The TCR is a multichain complex with four invariant chains CD3 gamma, delta and epsilon that each contain a single ITAM and the TCR zeta chain that contains three ITAM. The present study explores the protein interactions of the doubly phosphorylated CD3 gamma, delta, epsilon ITAM to determine whether they have common or unique biochemical properties. The data show that the doubly phosphorylated ITAM all bind the PTK ZAP-70, but the ITAM also variably bind the PTK p59fyn and the adapters Shc, Grb-2 and the p85 regulatory subunit of phosphoinositol 3' kinase. The CD3 and zeta ITAM display a hierarchy of ZAP-70 binding: zeta 1 = gamma = delta > zeta 3 > zeta 2 = epsilon. Shc, Grb-2 and p85 could bind the zeta ITAM and the CD3 gamma and delta ITAM, but not the CD3 epsilon ITAM. There were also subtle differences in the hierarchy of reactivity of these adapters for the CD3 gamma, delta and zeta ITAM that show that the zeta, CD3 gamma, delta and epsilon ITAM have different binding properties. The present study thus shows that the different ITAM of the TCR/CD3 complex can interact with different cytosolic effectors, indicating that differential ITAM phosphorylation during T cell activation could be a mechanism to generate signaling diversity by the TCR complex.
Amino Acid Sequence↗
Strategies to overcome the anti-Gal alpha (1-3)Gal reaction in xenotransplantation.
Explore the source record for details and available documents.
Animals↗
A comparison of the interaction of Shc and the tyrosine kinase ZAP-70 with the T cell antigen receptor zeta chain tyrosine-based activation motif.
Tyrosine-based activation motifs (TAMs) define a conserved signaling sequence, EX2YX2L/IX7YX2L/I, that couples the T cell antigen receptor to protein tyrosine kinases and adapter molecules. The present study shows that phosphorylation of both tyrosines within the motif is required for high affinity binding of the tyrosine kinase ZAP-70 whereas phosphorylation of the single COOH-terminal tyrosine within the motif is optimal for the binding of the adapter Shc. There were also quantitative differences in the ZAP-70 and Shc association with the zeta 1-TAM since nM concentrations of the doubly phosphorylated zeta 1-TAM are sufficient for ZAP-70 recruitment whereas micromolar levels of singly phosphorylated TAMs are necessary for Shc binding. Shc is tyrosine phosphorylated in antigen receptor-activated T cells and can potentially form a complex with the adapter molecule Grb2 and could thus recruit the Ras guanine nucleotide exchange protein Sos into the antigen receptor complex. The present data show that Grb2 can bind to the phosphorylated TAM, but this binding is independent of Shc and there is no formation of zeta 1-TAM.Shc.Grb2.Sos complexes in antigen receptor-activated cells. Accordingly, Shc function should not be considered in the context of Grb2/Sos recruitment to the T cell antigen receptor complex.
Adaptor Proteins, Signal Transducing↗
The role of tyrosine phosphorylation in the interaction of cellular tyrosine kinases with the T cell receptor zeta chain tyrosine-based activation motif.
Immunoglobulin receptor family tyrosine-based activation motifs (ITAM) define a conserved signaling sequence, EX2YX2L/IX7YX2L/I, that mediates coupling of the T cell antigen receptor (TCR) to protein tyrosine kinases (PTK). In the present study, we explored the role of phosphorylation of the two ITAM tyrosine residues in the interactions of the motif with the PTK ZAP-70 and p59fyn. The data show that the phosphorylation of a single tyrosine within the motif enables binding of p59fyn, whereas phosphorylation of both tyrosines within the motif is required for maximal binding of the PTK ZAP-70. Quantitative binding experiments show that nanomolar concentrations of the doubly phosphorylated zeta 1-ITAM are sufficient for ZAP-70 recruitment, whereas micromolar levels of singly phosphorylated ITAM are necessary for p59fyn binding. ZAP-70 binds with low efficiency to a singly phosphorylated ITAM, but shows preferential binding to the C-terminal phosphotyrosine in the ITAM, whereas p59fyn binds selectively to the N-terminal phosphotyrosine. The present data thus show that there is the potential for a singly phosphorylated ITAM to couple to cellular PTK. Moreover, the data suggest a mechanism for heterogeneity in signal transduction responses by the TCR, since ITAM could differentially couple the TCR to downstream signaling events depending on their phosphorylation state.
Amino Acid Sequence↗
Enzymatic remodelling of the carbohydrate surface of a xenogenic cell substantially reduces human antibody binding and complement-mediated cytolysis.
The major obstacle to successful discordant xenotransplantation is the phenomenon of hyperacute rejection (HAR). In the pig-to-primate discordant transplant setting, HAR results from the deposition of high-titre anti-alpha-galactosyl antibodies and complement activation leading to endothelial cell destruction and rapid graft failure. To overcome HAR, we developed an enzymatic carbohydrate remodelling strategy designed to replace expression of the Gal alpha-1,3-Gal xenoepitope on the surface of porcine cells with the non-antigenic universal donor human blood group O antigen, the alpha-1,2-fucosyl lactosamine moiety (H-epitope). Xenogenic cells expressing the human alpha-1,2-fucosyltransferase expressed high levels of the H-epitope and significantly reduced Gal alpha-1,3-Gal expression. As a result, these cells were shown to be resistant to human natural antibody binding and complement-mediated cytolysis.
Animals↗