Search PubMed⌕ Search

Biomedical subjects

M C Winslet

Publications and source records attributed to M C Winslet.

At least 37 records · Page 2Linked to original sources
PubMed1996

Strengths and weaknesses of laparoscopic and open mesh inguinal hernia repair: a randomized controlled experimental study.

There are no objective data available on the relative strengths of inguinal hernia repairs. The aim of this randomized controlled study was to measure th force required to disrupt laparoscopic and open mesh repairs in a porcine model. Eleven pigs had inguinal hernia repair following randomization to an open mesh group (n = 5) or a transabdominal preperitoneal laparoscopic group (n = 6). Four weeks after operation the pigs were killed and the pelvic girdles were mounted in a test jig on a mechanical testing machine. The applied disruption forces were measured and recorded. Mean(s.d.) force required to disrupt the normal inguinal canal (n = 11) was 68.6(30.1) N with no difference between groups. The open mesh repair required 110.3(41.4) N and the laparoscopic mesh 220.0(95.2) N. Both open and laparoscopic mesh repairs were stronger than the normal side (P < 0.03). The laparoscopic mesh repair was stronger than the open mesh repair (P = 0.04). This model provides a standardized method for mechanically testing inguinal hernia repairs in pigs. It confirms that both open and laparoscopic mesh hernia repairs are stronger than the non-herniated normal side at 4 weeks after operation. Laparoscopic mesh repair is stronger than open mesh repair. The weakest points of the repairs correlate well with those identified in clinical reports.

Animals↗
PubMed1996

Effects of different cold preservation solutions on restoration of hepatic energy metabolism during cold reperfusion.

Rat livers were flushed with different preservation solutions and stored at 4 degrees C for 24 h before being reperfused with a synthetic air-equilibrated, water-based solution. Four solutions were tested using this isolated rat liver model: Marshall's hypertonic citrate (HC); modified University of Wisconsin solution (Mod UW); a histidine-based solution (HIS); and a histidine-lactobionate-raffinose-based solution (HLR). After storage, livers were perfused at 4 degrees C for a period of 2 h and biopsy samples taken, at different time points, to investigate energy metabolism. Livers stored in HLR and HIS had higher 24-h storage levels of ATP (0.41 and 0.24 mumol/g respectively; P < 0.05) than those stored in Mod UW and HC. On reperfusion, all groups regenerated ATP by 1-2 h. However, significantly greater levels of ATP regeneration occurred in livers stored in the HLR (1.6 +/- 0.08 mumol/g) and Mod UW (1.3 +/- 0.18) than HC (0.58 +/- 0.19) and HIS (0.96 +/- 0.12); P < 0.05. Energy charge (1) (EC) recovered in all groups but was significantly higher in HLR and Mod UW (0.79 and 0.68, respectively; P < 0.05) than HC and HIS. These represent 95% (HLR) and 80% (Mod UW) of values observed in FIL. During the reperfusion period, total adenine nucleotide levels (TA) did not vary significantly within each storage group, except in the HIS solution. However, TAs were greater with livers stored for 24 h in HLR (2.5 +/- 0.25) and Mod UW (2.7 +/- 0.20) than those the other two storage groups (P < 0.05 in each case). This study has demonstrated that it was possible to resuscitate liver energetics after prolonged hypothermic ischemia by a period of cold reperfusion, and the method can differentiate between preservation solutions. The livers stored in each solution showed varying degrees of success in regeneration of ATP and EC, demonstrating that oxygen was not a limiting factor when using an air-equilibrated perfusate. The solutions providing the better preservation conditions gave the greater resuscitation of liver energetics (Mod UW and HLR). Overall, livers stored in HLR had the greatest resuscitation of energy metabolism, which correlates with survival data from other studies (29-31, 33).

Adenosine↗
PubMed1996

The influence of age on the surgical management of carcinoma of the stomach.

The medical records of 31,808 patients with gastric cancer registered with the West-Midlands Cancer Registry between 1957-1981 were reviewed to determine the influence of age on presentation, stage assessment, management, survival and mortality rates. When analysed by stage, and excluding post-operative deaths, survival was similar in all age groups. This study confirms stage of disease to be the single most important prognostic factor. The inverse relationship between laparotomy and age implies inadequate assessment of stage in the elderly. The poor prognosis in unresected cases suggests that increased precise staging by laparotomy or laparoscopy will have minimal adverse effects. On the other hand this may result in increased resections and survival.

Age Factors↗
PubMed1996

Human liver cancer cells and endothelial cells incorporate iodised oil.

Iodised oil (lipiodol) administered via the hepatic artery localises selectively in primary liver cell cancers (hepatocellular carcinomas or HCCs) for prolonged periods and has been used as a vehicle for cytotoxic agents. Despite clinical use, the mechanism of lipiodol retention by tumours has remained unclear, embolisation of oil droplets in the tumour vasculature being the prevailing hypothesis. We have investigated the role of tumour and endothelial cells in lipiodol retention. Human liver tumour (Hep G2) cells and human umbilical vein endothelial cells in culture were exposed to lipiodol. Light microscopy using selective silver impregnation stains and transmission electron microscopy revealed lipiodol incorporation by both cell types, probably by pinocytosis. This was not associated with cellular injury in terms of cell lysis, cell replication or radio-labelled leucine uptake. Histological analysis of 24 HCCs either surgically resected or discovered incidentally at liver transplantation (with prior arterial injection of lipiodol) revealed vesicles of lipiodol in the cytoplasm of tumour cells and endothelial cells lining tumour vessels. Thus, lipiodol is likely to deliver cytotoxic agents directly into tumour cells and endothelial cells, both in vitro and in vivo. This may also apply to other lipids and to other human tumours. These findings have significant therapeutic implications.

Carcinoma, Hepatocellular↗
PubMed1995

Tumour vasculature--a potential therapeutic target.

The tumour vasculature is vital for the establishment, growth and metastasis of solid tumours. Its physiological properties limit the effectiveness of conventional anti-cancer strategies. Therapeutic approaches directed at the tumour vasculature are reviewed, suggesting the potential of anti-angiogenesis and the targeting of vascular proliferation antigens as cancer treatments.

Amino Acid Sequence↗
PubMed1994

Prospective randomized trial of Ivalon sponge versus sutured rectopexy for full-thickness rectal prolapse.

Ivalon sponge rectopexy is a safe reliable procedure in the management of rectal prolapse. Sutured rectopexy is simpler and avoids the use of foreign material. Sutured rectopexy is mandatory if synchronous resection is to be considered. Sixty-three patients (62 women) with full-thickness rectal prolapse were entered into a prospective randomized trial of Ivalon sponge rectopexy (31 patients) versus sutured rectopexy (32). Twenty patients (32 per cent) had coexistent incontinence (ten in each group). The operation was performed in the standard manner with a sutured rectangle of sponge or sutures alone placed along the length of the sacrum. Postoperative morbidity occurred in nine patients (14 per cent) of whom three underwent a sutured procedure and six Ivalon rectopexy: wound infection in three, chest infection in two, urinary tract infection in two and thromboembolism in two. There were no deaths within 30 days. At a median follow-up of 47 months prolapse had recurred in two patients (3 per cent), one in each group, 14 (22 per cent) suffered from incontinence (of whom five had undergone a sutured procedure), while 25 (40 per cent) had developed constipation (of whom 15 had received Ivalon rectopexy). The medium-term results of rectopexy by suture alone are equivalent to those obtained following the conventional Ivalon procedure. These data suggest that Ivalon rectopexy could now be abandoned.

Adult↗
PubMed1994

Iodized oil in the treatment of hepatocellular carcinoma.

When injected into the hepatic artery the contrast agent Lipiodol (iodized poppy seed oil) is selectively retained by hepatocellular carcinoma (HCC) for a prolonged period of time. Liver computed tomography (CT) performed after Lipiodol angiography is more sensitive than ordinary CT at imaging HCC. Arterial administration of cytotoxic drugs and radioisotopes conjugated to Lipiodol has been shown to be reasonably safe in patients with irresectable HCC. These therapies, often combined with embolization, provide effective palliation, better tumour response and improved survival compared with other available treatments. Their use as a preoperative adjunct to surgical resection of HCC is controversial.

Animals↗
PubMed1994

Mucosal glucosamine synthetase activity in inflammatory bowel disease.

Abnormalities in colonic glycoprotein synthesis have been implicated in the pathogenesis of ulcerative colitis and Crohn's disease. Glucosamine synthetase is the rate-limiting step in the biosynthesis of gastrointestinal glycoprotein and has been measured in control subjects (N = 23) and patients with ulcerative colitis (N = 26) or Crohn's disease of the colon (N = 20) classified according to the macroscopic status of the rectum. Glucosamine synthetase activity was relatively constant around the normal colon but lower levels were found in the terminal ileum. In ulcerative colitis, glucosamine synthetase activity was similar to controls (24.0 +/- 1.9) mmol/g wet (wt/hr) irrespective of disease activity (quiescent: N = 13, = 27.3 +/- 1.9; active N = 16, = 26.2 +/- 2.3). Rectal glucosamine synthetase activity was normal in the presence of active Crohn's proctocolitis (29.4 +/- 3.1) but raised in patients with Crohn's colitis and rectal sparing (37.2 +/- 4.9 P < 0.02). Glucosamine synthetase activity was strongly influence by the degree of epithelial preservation.

Colitis, Ulcerative↗
PubMed1994

Faecal diversion for Crohn's colitis: a model to study the role of the faecal stream in the inflammatory process.

The high incidence of clinical remission after faecal diversion for Crohn's colitis suggests the faecal stream may play a part in the inflammatory mechanism. The effect of faecal diversion (n = 22) and restoration of intestinal continuity (n = 10) was assessed in patients with Crohn's colitis and compared with controls. Faecal diversion produced significant improvement in the disease activity index mean (SEM) (before 176 (9); after 114 (9), p < 0.01) and serum albumin concentrations (before 33 (3.0); after 38 (3.0), p < 0.05) in all patients with Crohn's colitis. The crypt cell production rate (CCPR) was maintained after faecal diversion for Crohn's colitis but fell in the control group (before = 3.6 (0.8)), at two (1.4 (0.4), p < 0.02), and six weeks (1.6 (0.4), p < 0.05). Mucosal glucosamine synthetase activity, reflecting glycoprotein synthesis, was significantly lower in patients with Crohn's colitis (analysis of variance p < 0.05) after diversion but was maintained in the control group. Restoration of intestinal continuity failed to produce reciprocal changes. The sustained cellular proliferation and fall in glycoprotein synthesis in Crohn's colitis after faecal diversion may represent the end of an exaggerated protective response and regenerative hyperplasia after exclusion of the faecal stream. This study suggests the faecal stream may participate in the inflammatory process in Crohn's colitis. The underlying mechanism is unknown.

C-Reactive Protein↗
PubMed1994

Submammary approach for the excision of mammographically localised lesions of the breast.

OBJECTIVE: To describe the results of a submammary incision for the removal of impalpable, mammographically diagnosed lesions. DESIGN: Open study. SETTING: District hospital. SUBJECTS: 8 patients with deep, impalpable, mammographically suspicious lesions. INTERVENTIONS: Excision biopsy by the submammary approach. MAIN OUTCOME MEASURES: Complete excision judged radiologically and histologically, and cosmetic result. RESULTS: All lesions were completely excised both radiologically and histologically. Three patients had ductal carcinoma in situ and five had benign microcalcification. Cosmetic results were excellent in all cases. CONCLUSION: The incision gives excellent results after excision biopsy of deep or peripheral lesions of the breast, but is contraindicated if invasive carcinoma is suspected.

Adult↗
PubMed1993

Transcaecal ileal diversion in the management of the 'at risk' distal colonic anastomosis.

Transcaecal ileal diversion has been used in association with primary resection and anastomosis to defunction an elective distal colonic anastomosis in 10 patients and to allow on-table colonic lavage with subsequent colonic defunction in 11 patients presenting as an emergency with distal colonic obstruction. Post-operative wound sepsis occurred in four patients (19%) with a clinical anastomotic leak in one patient. The median hospital stay was 14 (10-19) days. Transcaecal ileal diversion is simple to perform. It may facilitate primary resection and anastomosis in both the elective and emergency situation without increasing morbidity, mortality or the hospital stay.

Aged↗
PubMed1993

Fecal diversion in the management of Crohn's disease of the colon.

The clinical course of 44 patients undergoing elective proximal fecal diversion for Crohn's disease of the colon is reported. Sustained disease remission was obtained in 31 patients (70 percent). Diversion was associated with a significant reduction in steroid requirements (P < 0.01) and a significant improvement in hemoglobin (P < 0.001), erythrocyte sedimentation rate (P < 0.001), and albumin (P < 0.05). Sixteen patients (36.4 percent) have required a proctocolectomy, 19 patients (43.2 percent) remain defunctioned, and four patients (9 percent) have died. Five patients have had intestinal continuity restored, which has remained intact in four patients for a mean follow-up of 99 (range 21-153) months. Fecal diversion for Crohn's disease of the colon produces a high incidence of sustained disease remission, but for the majority of patients the prospect of future restoration of intestinal continuity is limited.

Adolescent↗
PubMed1993

Long-term results of large-dose, single-session phenol injection sclerotherapy for hemorrhoids.

PURPOSE: The aim of our study was to assess the medium to long-term outcome following single session large dose injection sclerotherapy for symptomatic hemorrhoids. METHODS: One hundred eighty-nine patients (male = 106, female = 83, median age, 51; range, 20-85 years) were assessed following single-session, large-dose (3 x 5 ml) phenol injection therapy. The most frequent complaint was bleeding (100 percent). RESULTS: At four-year follow-up, 53 patients (28.0 percent) were cured, 26 (13.7 percent) were improved, 35 (18.5 percent) remained unchanged, 59 (31.2 percent) deteriorated, and 16 (8.5 percent) required surgical intervention. Among the patients who were not cured, symptoms were minimal in 50 percent. Sclerotherapy was associated with a reduced incidence of bleeding (P < 0.05) but an increase in difficulty in perineal cleaning was observed (P < 0.05). CONCLUSION: Large-dose, single-session sclerotherapy provides only short-term benefits in the majority of patients with symptomatic hemorrhoids.

Adult↗
PubMed1993

A national audit of antimicrobial prophylaxis in vascular surgery.

A standard questionnaire on antimicrobial prophylaxis for elective and emergency vascular surgery was sent to 262 practising members of the Association of Vascular Surgeons (U.K.). The response rate was 68.3%. A cephalosporin based regime was used in 61.1% of cases while penicillin was used in 39.3% and an aminoglycoside in 6.5%. More than one antibiotic was routinely used in 15.6% of cases, with specific anti-anaerobic cover in 19%. Prophylaxis was used in all cases using a prosthetic graft, but in only 76% of cases using autogenous vein (p < 0.05). A single dose regime was most commonly used for autogenous vein graft (14% vs. 4.5%, p < 0.05), whilst overall a three dose regime was most popular. Some 2.8% of respondents specified a differing regime for supra- and infrainguinal surgery whilst 4.5% modified their regime in emergency cases. Despite its theoretical limitations, a three dose cephalosporin regime is the most commonly prescribed "prophylactic" regime for all forms of vascular surgery in the U.K.

Anti-Bacterial Agents↗
PubMed1993

The influence of ileal pouch-anal anastomosis for ulcerative colitis on ileal glycoprotein synthesis.

Restorative proctocolectomy and ileal pouch-anal anastomosis are frequently associated with the onset of low-grade inflammation, colonic metaplasia, and pouchitis. The influence of intestinal adaptation and inflammatory activity on ileal glycoprotein synthesis (GS) has been assessed. Ileal GS activity in controls (n = 13, 28.9 +/- 3.6) was similar to that of patients with ulcerative colitis (n = 18, 26.4 +/- 3.6) irrespective of the presence of backwash ileitis (n = 6, 22.0 +/- 4.0). Ileoanal pouch construction was not associated with a significant change in ileal GS activity regardless of the presence of low-grade inflammation (n = 19, 25.9 +/- 2.2), frank pouchitis (n = 5, 24.4 +/- 4.6), or transformation to a colonic type of mucosa (n = 6, 25.4 +/- 5.2). The transformation of ileal mucosa from an absorptive to a storage function is associated with characteristic morphologic and inflammatory changes but does not produce a protective response mediated by increased GS.

Adaptation, Physiological↗
PubMed1993

A pathophysiologic study of diversion proctitis.

Diversion proctitis occurs with variable frequency after exclusion of the fecal stream. Its importance lies in the inability to differentiate it from other types of proctitis that may result in inappropriate therapy and a reluctance to recommend stoma closure. The effect of fecal diversion (n = 18) and restoration of intestinal continuity (n = 10) on human rectal mucosa in patients without inflammatory intestinal disease has been prospectively evaluated. Fecal diversion was associated with macroscopic inflammation in 55 percent of the patients and histologic inflammation in 72 percent, with a variable incidence of aphthoid ulceration, crypt abscess formation and submucosal nodularity. Restoration of continuity was associated with improvement in histologic features in all patients, but the mucosa returned to normal in only 50 percent of the patients. Onset or resolution of diversion proctitis was not associated with any significant changes in colonic cellular proliferation, glycoprotein synthesis or mucosa-associated or luminal flora. The only diagnostic feature of defunctioned proctitis remains its resolution on reintroducing the fecal stream.

Diagnosis, Differential↗