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Biomedical subjects

C Sutton

Publications and source records attributed to C Sutton.

13 recordsLinked to original sources
PubMed1992

Effects of design geometry of intravascular endoprostheses on stenosis rate in normal rabbits.

To investigate the effects of gaps between the individual wire coils of a shape memory Nitinol alloy intravascular endoprosthesis, 20 stents with and without gaps were implanted transluminally into the infrarenal abdominal aortas of 10 normal rabbits after balloon angioplasty. Digital subtraction angiography (DSA) was done at 4, 12, 16, 20, and 24 weeks after stent implantation to examine the stenosis rate and major side branch patency. Stenosis rate within stents with gaps were significantly lower than those without gaps: 8.1 +/- 5.0% versus 15.0 +/- 6.8% at 12 weeks, 13.6 +/- 6.0% versus 26.0 +/- 9.4% at 24 weeks by DSA, p greater than 0.005 and p less than 0.01 respectively. The maximum and mean neointimal thickness measured histologically at the time of animal death correlated significantly to the narrowest diameter obtained from the DSA studies, (r = 0.84 and r = 0.79, respectively, p less than 0.01). Greater hyperplasia of the neointima was evident in the stented arterial segments with stents without gaps compared with those with gaps (83 +/- 22 versus 187 +/- 46 microns mean thickness, p less than 0.001). The patency rate of the side branches in the stented arterial segment was significantly (p less than 0.05) higher in stents having gaps. These results suggest that the placement of gaps between wire pitches reduced the neointimal thickness within stents and prevented the obstruction of arterial side branches.

Angioplasty, Balloon↗
PubMed1992

The aftermath of youth suicide--providing postvention services for the school and community.

Suicide is one of the leading causes of death in adolescence. Due to the risk of contagion and maladaptive coping responses in the aftermath of suicide, clinicians have responded by developing postvention services. Based on a considerable amount of experience in this field, target groups of individuals have been identified to receive such assistance. These groups include school administrators, staff, students, families, and community members at large. In addition, it has become clear that the local media response to suicide is of critical importance, and that school administrators and local mental health officials should work effectively with reporters so that news stories do not contribute to suicide contagion.

Adaptation, Psychological↗
PubMed1992

Operative laparoscopy.

Minimally invasive surgery is going through a rapid phase of evolution and over a relatively short time we have witnessed progress from simple ablative procedures such as the division of adhesions and destruction of endometriosis to far more complex operations such as laparoscopic myomectomy, hysterectomy, and, perhaps the hardest of all, cul-de-sac dissection and resection of bowel involved in dense fibrotic endometriosis. Some of these newer procedures reach the very limits of technical virtuosity and are extremely time consuming and will need careful appraisal before their true place in clinical gynecology is established.

Endometriosis↗
PubMed1991

Purification of recombinant human prostromelysin. Studies on heat activation to give high-Mr and low-Mr active forms, and a comparison of recombinant with natural stromelysin activities.

Recombinant human prostromelysin was purified in a single step using Procion Red-Sepharose chromatography. The purified prostromelysin was self-activated to high-Mr (45,000) and low-Mr (28,000) forms by incubation at 55 degrees C without the addition of extraneous activators. The two forms of stromelysin were subsequently separated, again using Procion Red-Sepharose. Both of the heat-activated recombinant forms demonstrated similar specific activities (for the macromolecular substrates casein, gelatin, elastin, proteoglycan and type IV collagen) when compared with either heat- or trypsin-activated natural stromelysin. The heat-activated recombinant stromelysins both showed similar abilities to potentiate activation of human procollagenase when compared with trypsin-activated natural stromelysin.

Amino Acid Sequence↗
PubMed1991

Purification and characterization of Ku-2, an octamer-binding protein related to the autoantigen Ku.

The octamer motif (ATTTGCAT) is an important regulatory element in eukaryotic gene expression. A previously unidentified protein that recognizes this motif has been isolated from the human B cell line, Daudi. The protein, which we term Ku-2, bears a close resemblance to the DNA-binding autoantigen Ku. Like Ku, it is a heterodimer with subunits of 83 and 72 kDa; antisera raised against either subunit of Ku cross-react with Ku-2. Two peptides have been sequenced and show a strong similarity to regions in the corresponding subunits of Ku. The sequences are not identical, however, suggesting that Ku-2 may be a B cell homologue of Ku. Both Ku and Ku-2 bind to the termini of DNA duplexes, but Ku-2 also binds to an internal octamer motif. It is not known whether Ku shares the latter property or whether the octamer binding is a consequence of sequence differences between the two proteins. Ku-2 does not react with antisera against the POU domain of the octamer-binding protein Oct-2, indicating that the DNA binding domains of the two proteins are dissimilar despite the ability of both to bind to the octamer motif. We discuss the evidence for the existence of a family of octamer-binding proteins related to Ku.

Amino Acid Sequence↗
PubMed1991

The V3 loops of the HIV-1 and HIV-2 surface glycoproteins contain proteolytic cleavage sites: a possible function in viral fusion?

Located close to the crown of the V3 type-specific neutralization loop of the human immunodeficiency virus type 1 (HIV-1) (IIIB) SU glycoprotein gp120, are several potential sites that should be susceptible to proteolytic cleavage by enzymes of trypsinlike or chymotrypsinlike specificity, or by aspartic proteinases. The linkages potentially sensitive to chymotryptic/aspartic proteinase cleavage are retained also within the equivalent domain of HIV-2 (ROD) gp105. We show that thrombin and tryptase cleave HIV-1 gp120 specifically at the tryptic site (GPGR decreases AFVT), and that cathepsin E, an endosomal aspartic proteinase, cleaves at the chymotrypsinlike site (GPGRAF decreases VT). HIV-2 gp105 is also cut by cathepsin E at a site (QIML decreases MSGH) in its V3 loop. Cleavage of HIV-1 gp120 by thrombin is enhanced by sCD4 binding, but is prevented by transient exposure of gp120 to nonionic detergent. Thrombin treatment of HIV-1 gp120 destroys the binding sites for some neutralizing monoclonal antibodies (MAbs) on the V3 loop, but does not affect the affinity of gp120 for sCD4. Conversely, binding of neutralizing MAbs to the HIV-1 V3 loop prior to addition of thrombin or cathepsin E blocks the cleavage reactions, and the binding of some HIV-positive sera to gp120 blocks thrombin cleavage. Analysis of published sequences suggests that all HIV-1, HIV-2, and simian immunovirus (SIV) isolates contain potential proteolytic cleavage sites at similar positions in their V3 loops or equivalent domains. We suggest that cleavage of the V3 loop by a cell surface or endosomal proteinase occurs during the HIV-cell fusion reaction, and that neutralizing antibodies directed against the V3 loop might act by inhibition of this reaction.

Amino Acid Sequence↗
PubMed1990

Mutilating palmoplantar keratoderma with periorificial keratotic plaques (Olmsted's syndrome).

We report the case of a boy, now aged 4 years, with a progressive, painful and disabling palmoplantar keratoderma, associated with well-defined hyperkeratotic plaques around the mouth and nostrils. His mother has an identical palmoplantar keratoderma. The palmoplantar keratoderma failed to improve with etretinate, but considerable benefit resulted from full-thickness excision of the skin of both palms, followed by skin grafting. We believe that he has a distinctive but extremely rare form of hereditary palmoplantar keratoderma, first described by Olmsted.

Child, Preschool↗
PubMed1990

Laser laparoscopy in the treatment of endometriosis. A 5-year study.

The carbon-dioxide laser used laparoscopically provides a precise and virtually bloodless technique for the vaporization of endometriotic implants in the pelvis. The technique has been used at St Luke's Hospital, Guildford, for the past 6 years and this report presents 228 consecutive patients with endometriosis treated during the 5 years between 1982 and 1987 and followed up for between 1 and 6 years. Pain was improved in 70% and 80% of the 56 infertile patients with endometriosis as the only identifiable abnormality conceived. Of the 54 pregnancies, only 37 (69%) had a successful outcome, reflecting the high pregnancy failure rate found in women with endometriosis. Hospital stay was relatively short and complications were few and usually minor and there was no injury or morbidity caused by laser energy. The main advantage of laser laparoscopy in endometriosis is that patients may be treated at the time of diagnosis with less need for medication and no delay before conception is attempted.

Adolescent↗
PubMed1989

Purification and sequencing of glycosylation variants of BSF-1, as a MAF, from the EL-4 leukaemia cell line.

Macrophage activation activity was characterized from a PMA-induced subclone of the murine EL-4 leukaemic cell line. The MAF was purified from the cell line culture supernatant by concentration, CM-Sepharose and lentil lectin Sepharose chromatography, AcA 54 gel filtration, Mono Q FPLC and reverse phase HPLC. Four protein bands of different abundance were observed on SDS-PAGE with molecular weights of 17,500 to 21,000 Da. Three of the four proteins were sequenced from the N-terminal and shared homology with the published sequence of BSF-1. Variation of the molecular weight due to glycosylation was demonstrated by N-glycanase treatment, all four proteins gave a band of 14,200 Da after deglycosylation. Both glycosylated and deglycosylated forms of BSF-1 were equally active in the MAF assay. A monoclonal antibody to BSF-1 neutralized 80% of the activity from crude culture supernatants in the MAF assay. These studies have indicated that BSF-1 is the major, if not the only, MAF activity from this particular subline of the murine EL-4 leukaemic cell line.

Amino Acid Sequence↗
PubMed1977

Practical approach to problems of the parturient diabetic in developing countries.

Improved management of diabetic pregnancies at Lautoka Hospital, Fiji, in 1976 resulted in a neonatal survival rate of 100%. Management included attempts to control the maternal blood glucose concentrations with insulin and delaying delivery until there was enough surfactant in the liquor to ensure a viable infant. The techniques are simple to use and require only minimal technological facilities.

Adult↗
PubMed1976

A short-term, intensive workshop approach for the treatment of human sexual inadequacy.

A rapid treatment approach to common sexual dysfunctions has been used in treating 59 couples, including 74 symptomatic individuals. Using a multidisciplinary team approach in an intensive 2 1/2 day workshop format, symptom improvement has been obtained in 86.5% of the dysfunctional individuals, with complete symptom reversal in 63.5%. The intensive workshop format has resulted in a saving of both patient and professional time and is seen as a viable and successful alternative to more time-consuming approaches of treating various sexual dysfunctions.

Adult↗