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Biomedical subjects

M Walton

Publications and source records attributed to M Walton.

At least 19 recordsLinked to original sources
PubMed1995

Button-pexy fixation for repair of ileostomy and colostomy prolapse.

Intestinal stomas are used in the surgical management of a number of congenital and acquired gastrointestinal conditions. Minor stomal complications are relatively common and are often well managed with nonoperative measures. Stomal prolapse may not represent a serious problem, but occasionally it requires surgical correction because of severe skin excoriation, bleeding, or incarceration of the bowel. The authors describe the treatment of stomal prolapse with the technique of button-pexy fixation, as originally described by C.W. Mayo.

Colostomy↗
PubMed1995

Testicular fate after incarcerated hernia repair and/or orchiopexy performed in patients under 6 months of age.

This study assessed testicular viability after 476 inguinal procedures performed in 338 infants under 6 months of age, between 1974 and 1993. One hundred twenty-one elective hernia repairs (contralateral explorations) were compared with 355 hernia repairs complicated by incarceration and/or orchiopexy. Clinical examination of 323 testes in the early postoperative period showed 20 atrophic testes. Since January 1994, 71 of the 338 patients have had testicular measurements obtained through ultrasonography (US). An additional 13 atrophic testes were found during US examination. Of these, nine were believed to be normal during early postoperative examination. Assuming that US examination will confirm atrophy in the 20 atrophic testes noted early in the postoperative clinical evaluation, and that all other testes not yet scanned are found to be normal, the minimal atrophy rate (MAR) would be 9.3% (33 of 355). Neither operative nor early postoperative testicular assessment correlates with ultimate testicular survival. Testicular pathology may become more evident after puberty, and the real incidence of atrophy may increase.

Atrophy↗
PubMed1995

Inflammatory cloacogenic polyps in children.

Inflammatory cloacogenic polyp (ICP) is a rare lesion arising in the region of the anorectal transitional zone. It is likely caused by occult internal prolapse. Most cases reported in the literature are in the adult population. This is a report of ICP in four children. Awareness of this entity in children is important because of both the propensity for recurrence or persistence of the polyps if the underlying etiology is not corrected, as well as the long-term implications of internal intussusception: procidentia, descending perineum syndrome, and ultimately, incontinence.

Adolescent↗
PubMed1995

Tethered cord with anorectal malformation, sacral anomalies and presacral masses: an under-recognized association.

The association of congenital anal stenosis, scimitar-shaped sacral defect and a presacral mass is known as the Currarino triad. These patients present with constipation of variable severity which may result from a combination of compression by the mass, neurogenic dysfunction as well as anal stenosis itself. We have treated three patients who illustrate the spectrum of severity of this condition. All had an associated tethered cord. One was cured by a single anal dilatation, cord release and anterior meningocele repair. The second did not improve after anoplasty and neurosurgical intervention. A previously diagnosed rectal ectasia was felt to be contributory to the constipation and was treated by low anterior resection with excellent results. The third patient developed an ischiorectal abscess that required drainage and colostomy after unsuccessful dilatation of a very tight and deeply scarred anal stenosis. A subsequent tethered cord release and closure of the anterior meningocele was followed by an anoplasty. Colostomy was closed at a later date. In all patients with anal stenosis a search should be made for a presacral mass and its associated sacral defect. Release of the tethered cord, resection of the presacral mass and/or closure of the anterior meningocele are essential for optimal functional results.

Abnormalities, Multiple↗
PubMed1993

High-performance liquid chromatographic assay for the measurement of the novel microtubule inhibitor 1069C85 in biological tissues and fluids.

1069C85 is a novel tubulin binder developed to circumvent the resistance associated with the Vinca alkaloids. Cytotoxic activity has been demonstrated in vitro against a variety of tumour cell lines, including a variant of the P388 leukaemia with acquired resistance to vincristine. A phase I clinical trial is planned and an assay suitable for preclinical and clinical pharmacokinetics has been developed. A high-performance liquid chromatographic (HPLC) assay is described which allows measurement of 1069C85 in plasma, urine, and tissue samples. The method uses reversed-phase chromatography with isocratic elution and detection by fluorescence at 406 nm following excitation at 340 nm. The assay is specific, sensitive (limit of sensitivity 0.25 ng/ml) and reproducible (coefficient of variation < 5%). The method has been used to study the pharmacokinetics of 1069C85 in Balb C mice following a single oral dose of 1 mg/kg. The maximum plasma concentration was reached 15 min after administration and subsequent elimination was slow with a half life of 6.5 +/- 2.2 h. The drug remained detectable in plasma, at 1 +/- 0.5 ng/ml, 24 h after this dose. This assay will be used to determine the pharmacokinetic profile of 1069C85 in mice and in a forthcoming phase I clinical trial.

Animals↗
PubMed1992

Helicobacter pylori eradication with doxycycline-metronidazole-bismuth subcitrate triple therapy.

Triple therapy containing tetracycline HCl is currently among the most efficient combination therapies for eradication of Helicobacter pylori. Substitution of doxycycline for tetracycline HCl offers advantages of less frequent dosing and extrarenal excretion. In this study patients with duodenal ulcer or non-ulcer dyspepsia positive for H. pylori were randomized to either doxycycline or tetracycline HCl triple therapy in conjunction with bismuth subcitrate and metronidazole. Of the 34 patients taking doxycycline, only 22 (65%) achieved H. pylori eradication at the 4-week rebiopsy, compared with 36 of 39 (92%) taking tetracycline HCl (p = 0.004). We conclude that doxycycline-containing triple therapy is less effective for H. pylori eradication and offers no clinical advantage over tetracycline HCl-containing triple therapy.

Adult↗
PubMed1991

Strength retention of chromic gut and synthetic absorbable sutures in a nonhealing synovial wound.

The rate at which absorbable sutures lose their mechanical strength in a slow healing wound is clinically important, particularly because the factors inhibiting normal healing are not always apparent at the time of closure. Sutures of chromic catgut and two monofilament absorbable synthetic suture materials (polydioxanone and polyglyconate) were used to close a synovial incision in the knees of sheep. A corticosteroid was applied around the wound resulting in minimal tissue healing when the sutures were retrieved up to six weeks later. The failure load and maximum tensile strength of the retrieved sutures were measured. The mechanical degradation of the materials followed a pattern similar to that in normally healing wounds except that the early fragmentation of chromic gut and polydioxanone occurred far less frequently and neither weakened further after three weeks. Polyglyconate was significantly the strongest material up to three weeks but thereafter continued to weaken. The strength of absorbable sutures was retained longer than in a healing lesion probably because of the absence of the phagocytic cells of an inflammatory tissue.

Animals↗
PubMed1990

Cure of duodenal ulcer after eradication of Helicobacter pylori.

Eighty-two patients, whose duodenal ulcers were recurrent or resistant to H2-receptor antagonist therapy, were entered in a treatment protocol of ranitidine followed by a four-week "triple therapy" course to eradicate Helicobacter pylori (HP) infection. The triple therapy consisted of colloidal bismuth subcitrate, tetracycline and metronidazole. Duodenal ulcer healed in all 78 patients available for endoscopy and H. pylori infection was shown to be eliminated in 75 patients (96%) at rebiopsy four weeks after cessation of therapy. In these 75 remaining patients the relapse rates for H. pylori infection and duodenal ulcer were studied endoscopically, yearly and at any recurrence of symptoms. At Year 1, 71 of 73 patients remained free of H. pylori infection (HP-negative) and duodenal ulcer. The corresponding figures subsequently were: Year 2, 57/57; Year 3, 34/34; Year 4, 15/15. No duodenal ulcers recurred in HP-negative patients who were followed for up to four years. Two patients of the original cohort of 75 HP-negative patients were HP-positive with endoscopic duodenitis at 12 months, and one at 36 months, but all were without reulceration. Distorted duodenal caps gradually returned to near-normal appearance in 80% of patients by two years. From this four-year follow-up study we conclude that duodenal ulcer disease will not recur provided the patient remains free of H. pylori.

Adult↗
PubMed1989

Strength retention of chromic gut and monofilament synthetic absorbable suture materials in joint tissues.

The rate at which absorbable sutures lose their mechanical strength in vivo is particularly important in orthopedic applications where high physical loads, often increased by early mobilization, severely test the strength of sutures. The failure load and maximum tensile strength of chromic catgut and two monofilament absorbable synthetic suture materials (polydioxanone and polytrimethylene carbonate) were measured up to six weeks after implantation in sheep as: (1) a suture securing a synovial incision and (2) coils located either within the synovial cavity of the knee or intramuscularly. Although all synovial wounds healed satisfactorily, the performances of the different materials varied. The strength of chromic gut was largely lost within a week and fragmentation occurred at Week 4. The synthetic materials lost their strength relatively slowly. Polytrimethylene carbonate degraded in a linear manner, remaining intact but with little strength by Week 6. Polydioxanone, though losing strength at a slower rate, tended to fragment early, which may be of clinical importance in situations of delayed wound healing.

Animals↗
PubMed1988

The aerobic cost of saltatory locomotion in the fowler's toad (Bufo woodhousei fowleri).

Studies of kangaroos suggest that hopping provides energy savings during locomotion at high speeds, although studies of small mammals suggest that hopping is no more economical than running. To obtain comparative data on anurans, we exercised Fowler's toads (Bufo woodhousei fowleri, 25.8 g) on treadmills at speeds ranging from 0.09 to 0.63 km h-1 while measuring oxygen consumption (VO2), endurance or hop kinematics. The toads walked at slow speeds and hopped at fast speeds. Steady-state VO2 (VO2,ss) increased linearly with speed to a maximum (VO2, max) of 1.17 ml O2 g-1 h-1 at 0.27 km h-1 and was nine times the average pre-exercise VO2. The maximum rate of oxygen consumption during treadmill exercise was comparable to VO2,max previously reported for less natural exercise regimes. At speeds greater than or equal to 0.27 km h-1, VO2,ss was independent of speed. At speeds less than or equal to 0.36 km h-1, toads moved for over 1h, but endurance decreased sharply at higher speeds. Hop rate, hop length, hop height and angle of take-off increased with speed. Hopping in B.w. fowleri was not less costly than running in other animals of similar body size and was inefficient at converting metabolic to mechanical energy. The present study suggests that hopping in toads, as in small mammals, is not economical during sustained locomotion and is most important during short bursts of high-intensity activity.

Animals↗
PubMed1988

Fibroblastic healing of grade II ligament injuries. Histological and mechanical studies in the sheep.

A method is described which produces an isolated Grade II injury in the medial collateral ligament of the sheep's knee. The untreated injury was followed in 32 animals for up to six weeks. Histology revealed progressive healing of the lesions by a cellular response mediated by fibrocytes rather than by the classically described inflammatory response. Mechanical testing showed that the tensile strength of the ligament was initially reduced to 13% of normal but that strength and compliance were regained after six weeks.

Animals↗
PubMed1983

Reactions of thigh tissues of sheep to blunt trauma.

Severe damage to the deep musculature of the thigh was caused by standardized crushing injuries applied to muscle overlying the femora of anesthetized sheep. The injuries caused an acute inflammatory response, with the formation of granulation tissue and, later, extensive scarring. Periosteal bone formed in all cases, in some instances resulting in a spike of bone that protruded into the overlying soft tissue. Heterotopic bone formed in 16.6% of the legs of sheep within three weeks to three months after trauma by intramembranous ossification within scar tissue replacing muscle tissue.

Animals↗
PubMed1983

Munchausen's syndrome or chronic factitious illness: a review and case presentation.

The psychosomatic disorder termed Munchausen's syndrome has gained official recognition in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, in which it is referred to as a "chronic factitious disorder with physical symptoms." Sporadic case reports have been published over the years. Few patients with this disorder allow themselves to be psychologically evaluated or seek treatment for the disorder itself. We report here an unusual case in which a young woman sought help for her hospital-peregrinating behavior.

Adult↗