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Biomedical subjects

D F Martin

Publications and source records attributed to D F Martin.

At least 73 records · Page 4Linked to original sources

Aspiration following stroke: is it related to the side of the stroke?

OBJECTIVE: To investigate the relationship between the side of stroke and the presence of aspiration on videofluoroscopy. DESIGN: Observational prospective study. SUBJECTS: Eighty-seven patients (50% female) admitted with an acute stroke to the University Hospital of South Manchester. METHODS: Patients admitted to the study underwent brain CT scanning and repeated videofluoroscopy. RESULTS: CT scanning was performed within a median three days (interquartile range 2-4 days) following stroke and videofluoroscopic (VF) examination (median 2, interquartile range 1-4 days following stroke) of their swallow. Seventeen (19.5%) patients were noted to be aspirating. There were no significant relationships at this time between side or site of lesion and the presence of aspiration. A second assessment was carried out at a median time of 29 days (interquartile range 26-45) following acute stroke. Nine of 69 (13.5%) patients were noted to be aspirating, seven of whom, had right hemisphere lesions (p < 0.01). CONCLUSIONS: Continuing aspiration may be related to the side of the cerebral lesion.

Adult↗

Fixation with bioabsorbable pins in chevron bunionectomy.

Fixation with bioabsorbable pins in distal chevron bunionectomy reduces the inconvenience and the risk of infection associated with fixation with stainless-steel Kirschner wires, which leaves a portion of the wires protruding from the skin. However, use of bioabsorbable implants has been reported to be associated with osteolysis and formation of a sinus with a sterile discharge. We studied the outcome and complications seen with use of poly-p-dioxanone pins and those seen with use of stainless-steel Kirschner wires after chevron bunionectomy in 114 patients (144 feet). We found no difference between the treatment groups with regard to the prevalence of complications or the stability of fixation. Notably, the prevalence of osteolysis was quite similar between the treatment groups; none of the feet that had had fixation with bioabsorbable pins had formation of a sinus with a sterile discharge. We believe that bioabsorbable pins can be used reliably to fix the site of the osteotomy for a distal chevron bunionectomy without undue risk of osteolysis or other complications.

Biocompatible Materials↗

Diffuse pigmented villonodular synovitis in a college football player.

In retrospect, it is evident that our patient had signs of PVS on initial presentation: suprapatellar pouch effusion and swelling out of proportion to discomfort. In addition, his first MRI scan showed characteristics of PVS: thickening and enhancement. Difficulty in reaching the diagnosis of PVS was aided by his asymptomatic return to football. Further confusing the issue, his initial presentation was directly associated with trauma, which is not pathognomonic for PVS. In conclusion, diffuse pigmented villonodular synovitis can be recognized early on MRI scans, which should be carefully examined, especially in the presence of large suprapatellar effusions. Diffuse PVS can be successfully treated with arthroscopic subtotal synovectomy.

Adolescent↗

Day-case transfer of inpatients for diagnostic and therapeutic endoscopic retrograde cholangiopancreatography.

BACKGROUND: To use facilities flexibly and efficiently, a diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP) service was offered to inpatients from referring hospitals on a day-case basis. METHODS: Patients were transferred by ambulance with a nurse escort and returned to the parent hospital after a short period of recovery. The activity of this service was audited. RESULTS: A total of 188 patients (70 men and 118 women of mean age 63.5 (range 22-94) years) were referred, 55 by physicians or geriatricians and 133 by surgeons from 19 hospitals up to 100 miles distant. Some 109 (58 per cent) had jaundice, 12 (6 per cent) cholangitis, seven (4 per cent) acute pancreatitis and 41 (22 per cent) abdominal pain. All patients arrived between 08:30 and 12:00 hours, all but 16 between 09:30 and 11:00 hours, and all but one with an escort; 129 patients travelled less than 10 miles. The mean time spent in the authors' hospital was 5.9 (range 2.2-9.5) h. The mean time spent away from the parent hospital by patient and escort was 7.0 (range 3.5-10) h. Cannulation failed in 12 patients (6 per cent), two with duodenal tumours. Sphincterotomy was performed in 70 cases, mechanical lithotripsy in seven and stents were inserted in 67. Nine patients were admitted, four for percutaneous stent insertion after failed ERCP and three for abdominal pain (one acute pancreatitis); two patients with sepsis and malignancy died after admission to this hospital. After return to the parent hospital, a further patient died following laparotomy for malignancy and five patients developed abdominal pain (three acute pancreatitis). CONCLUSION: These findings show that short-stay ERCP can be undertaken on transferred inpatients safely and efficiently without adverse effect on success or complication rates.

Adult↗

Evaluation of a delivery system providing long-term release of cyclosporine.

OBJECTIVES: To examine the clearance of cyclosporine after intravitreal injection and to assess the kinetics and toxic effects of an intravitreal device that provides sustained delivery of cyclosporine. METHODS: Rabbits were divided into two groups to evaluate (1) the elimination kinetics after 1-microgram and 10-microgram intravitreal injections of cyclosporine and (2) the levels produced after implantation of a device that contained cyclosporine over 6 months. The toxic effects of the intravitreal device over 6 months were assessed in rabbits and cynomolgus monkeys. RESULTS: After the 10-microgram injection, the half-life was longer (10.8 hours vs. 4.2 hours) and the distribution volume was smaller (1.7 mL vs 3.2 mL) than after the 1-microgram injection. This difference can be attributed to saturable partitioning of the drug. The device resulted in a vitreous concentration of approximately 500 ng/mL throughout the study period. In the rabbit it resulted in reversible lens opacification and decreased b-wave amplitude. This toxic effect was not detected in the monkey. CONCLUSIONS: The device produces sustained intravitreal levels of cyclosporine. Although it was associated with reversible toxic effects in the rabbit, it was well tolerated in primates. Sustained-release implants are a promising new treatment for chronic uveitis.

Animals↗

Postoperative hypopyon after intravitreal bovine thrombin for macular hole surgery.

PURPOSE: We used intravitreal autologous fibrinogen with bovine thrombin for the surgical closure of macular holes in 60 cases. METHODS: Pars plana vitrectomy with separation of the posterior cortical vitreous was performed after air/fluid exchange. One to two drops each of autologous fibrinogen and bovine thrombin (20 to 80 U) were instilled in each patient. RESULTS: Five (8%) of 60 patients developed a hypopyon without unusual pain on the first postoperative day. Inflammation responded to frequent topical corticosteroids within 48 to 72 hours. CONCLUSION: Postvitrectomy hypopyon after the use of bovine thrombin may represent an immune reaction that must be differentiated from endophthalmitis. We recommend careful observation and frequent topical corticosteroids.

Adult↗

Subfoveal choroidal neovascularization in punctate inner choroidopathy. Surgical management and pathologic findings.

PURPOSES: To evaluate submacular surgery for the management of subfoveal choroidal neovascularization in punctate inner choroidopathy, to describe the histopathology and ultrastructure of the excised subretinal tissue, and to propose a staging system that characterizes the development of choroidal neovascularization with associated subretinal fibrosis. METHODS: The authors reviewed the records of five patients (6 eyes) with punctate inner choroidopathy who underwent submacular surgery for subfoveal choroidal neovascularization. Surgical specimens were examined using light and transmission electron microscopy. RESULTS: Visual improvement was noted postoperatively in all six eyes, with follow-up ranging from 8 to 36 months (median, 14 months). Recurrences (6 in 4 eyes) were common. Five of the six recurrences required additional procedures: three were managed surgically, two with laser photocoagulation, and one with observation. "Bridging" of separate foci of choroidal neovascularization resulted in stellate or "dumbbell-shaped" areas of subretinal fibrosis in four of six eyes. Histopathologic evaluation of the excised tissue showed endothelial-lined vascular channels, retinal pigment epithelium, lymphocytes, plasma cells, fibrocytes, collagen fragments, and rarely, outer retinal elements. CONCLUSIONS: Subfoveal choroidal neovascularization in punctate inner choroidopathy may be managed with submacular surgery. Recurrences are common and may result in substantial loss of vision. Choroidal neovascular membranes with an accompanying fibrotic reaction are responsible for the stellate or dumbbell-shaped areas of subretinal fibrosis. No beneficial effect was demonstrated using corticosteroid treatment of the choroidal neovascularization.

Adult↗

Ciliary body endophotocoagulation during pars plana vitrectomy in eyes with vitreoretinal disorders and concomitant uncontrolled glaucoma.

PURPOSE: To investigate the efficacy of ciliary body endophotocoagulation during pars plana vitrectomy in eyes with medically uncontrolled glaucoma and concomitant vitreoretinal disorders. METHODS: The authors compared preoperative and postoperative intraocular pressure (IOP) and visual acuity in 21 eyes of 21 patients undergoing ciliary body endophotocoagulation with pars plana vitrectomy. RESULTS: Preoperative IOPs ranged from 22 to 59 mmHg (median, 46 mmHg). Visual acuity ranged from 20/200 to light perception (median, hand motions). Follow-up ranged from 3 to 18 months (median, 10 months). Postoperative IOPs ranged from 11 to 19 mmHg (median, 16 mmHg) at 6 weeks, 4 to 20 mmHg (median, 14 mmHg) at 3 months, 1 to 26 mmHg (median, 12 mmHg) at 6 months, and 0 to 48 mmHg (median, 12 mmHg) at 12 months. Postoperative visual acuity was statistically improved from preoperative visual acuity by 6 weeks. CONCLUSION: Ciliary body endophotocoagulation combined with pars plana vitrectomy can effectively treat concomitant glaucoma and vitreoretinal disorders.

Adult↗

Cytology of metastatic cutaneous melanoma to the vitreous and retina.

PURPOSE: The authors report one patient with definitive and one patient with presumed metastatic cutaneous malignant melanoma to the vitreous and retina diagnosed by cytologic evaluation of the vitreous and subretinal fluid. METHODS: A diagnostic vitrectomy was performed on two patients with atypical vitreous and retinal infiltrates. Additionally, subretinal fluid was obtained from the second patient. The specimens were processed for cytologic examination. The cytology specimens were compared with previously excised cutaneous melanomas from the patients. RESULTS: Examination results showed cells in the vitreous with high nuclear-to-cytoplasm ratios, coarse chromatin, and intracytoplasmic melanin pigment granules. The cytologic features were compared with the cutaneous malignant melanoma, and a diagnosis of metastatic melanoma was made. One patient eventually required enucleation, and the metastatic tumor in the other patient was controlled by local irradiation. CONCLUSIONS: Cytologic evaluation of the vitreous and subretinal fluid is helpful in establishing a diagnosis in patients with metastatic cutaneous melanoma to the vitreous and retina.

Aged↗

Successful treatment of progressive outer retinal necrosis syndrome.

PURPOSE: Progressive outer retinal necrosis is a destructive retinopathy found in patients with acquired immune deficiency syndrome. Treatment of this disorder has been unsuccessful in reported patient series, with the patients experiencing profound bilateral loss of vision. METHODS: We treated six patients with combination antiviral therapy, usually with intravenous foscarnet and either ganciclovir or acyclovir. RESULTS: These six patients retained a visual acuity of 20/100 or better in at least one eye for the remainder of their lives (a period > 4 months for each patient). Retinal detachments developed in four patients, for which vitrectomy and silicone oil tamponade were required. CONCLUSIONS: A combination of intravenous antiviral therapy and aggressive vitrectomy techniques to repair any associated detachments may allow the preservation of useful visual acuity in patients with progressive outer retinal necrosis. This is the first reported series of successful long-term treatment of patients with this disorder.

Acquired Immunodeficiency Syndrome↗

Rehabilitation programmes following arthroscopic meniscectomy in athletes.

The athlete with a meniscal injury can be returned to activity quickly and safely with appropriate treatment and rehabilitation. When injuries occur in the relatively avascular inner zones of the meniscus, partial meniscectomy is usually the treatment of choice. The rehabilitation programme should emphasise decreasing inflammation, restoring motion, increasing strength, and safe return to competition. This can begin preoperatively and progress through a phased programme which allows the athlete to participate in goal setting and advancement. By outlining the different phases of knee rehabilitation, the athlete and support team (coach, parent, trainer, therapist, physician) can progress to and plan appropriate return to sport. During this process, preventive measures for reinjury can be addressed, thereby maximising performance and safety.

Arthroscopy↗

Stenting for choledocholithiasis: temporizing or therapeutic?

Maxton and colleagues report their experience using biliary endoprostheses for treatment of failed common bile duct stone clearance after sphincterotomy. Of 283 patients with choledocholithiasis referred to their tertiary facility, 85 failed to have their ducts cleared with the first ERCP. There were 21 male and 64 female subjects; mean age was 77.5 yr. Clinical presentations were jaundice (39), cholangitis (23), and biliary colic and/or abnormal liver blood tests in the remainder. The patients were characterized as "elderly and ill with either jaundice or cholangitis present in almost 75%." Follow-up data were obtained for all patients. ERCP was first performed using a duodenoscope with a 3.2-mm instrument channel. A 7-French double pigtail stent was placed in each of the 85 patients with retained stones. Subsequent ERCP were performed at 2- to 3-month intervals using a therapeutic duodenoscope (4.2-mm instrument channel). A second stent was placed if stones remained in the bile duct after repeated extraction attempts. Patients deemed too frail and elderly for frequent ERCP had their first stent left in place, with stent exchanges and attempts at stone extraction every 6-12 months. Mechanical lithotripsy was used in 23 patients, extracorporeal shock wave lithotripsy (ESWL) in 11, and dissolution therapy via nasobiliary catheter in 10. Acute illnesses resolved in 84 of 85 patients, with significant decreases in bilirubin and alkaline phosphatase levels by the second ERCP. Six patients died with temporary stents in situ, one form a respiratory arrest the day of ERCP; the other deaths were unrelated to ERCP or choledocholithiasis. Fifty of the remaining 79 patients had successful stone clearance; 68% of these required two ERCP, 20% three ERCP, 6% four ERCP, and, in another 6%, a total of five ERCP were required before their ducts were free of stones. Seven cases of cholangitis among these 50 patients were treated successfully with i.v. antibiotics, fluids, and "early" stent replacement. Twenty-six patients had long term biliary drainage with the original stents in situ over 12 months. Four of these patients were among the six deaths, all unrelated to biliary stones or ERCP. Three patients were referred for surgical stone removal. The authors conclude that placement of a single 7-French stent after failure to clear common duct stones is safe, provides affective biliary drainage, can prevent the need for urgent surgical intervention, and allows for transfer of sick patients to centers of expertise. Further attempts at bile duct clearance were successful in most cases.

Aged↗

Does routine abdominal ultrasound enhance diagnostic accuracy in irritable bowel syndrome?

OBJECTIVE: The current recommendation that irritable bowel syndrome (IBS) should be diagnosed positively using minimum investigation raises the possibility that some disorders, particularly gynecological, may be overlooked. Transabdominal ultrasound is now sufficiently sophisticated to allow assessment of all abdominal viscera for associated pathology, and this study was designed to evaluate its role in the diagnosis of IBS. METHODS: An ultrasound scan was performed in 125 patients (100 females, 25 males) for whom a confident diagnosis of IBS had been made. RESULTS: No serious intra-abdominal pathology was encountered, but 20% of females and 8% of males had an ultrasound abnormality. None of these abnormalities resulted in any additional therapeutic measures. A hepatobiliary abnormality was found in similar proportions of males and females (10 vs 8%). Gallstones were most common (5 vs 4%), but in no individual were they considered to entirely account for the presenting symptoms. Eight percent of the women were found to have a pelvic abnormality, but it was not regarded as serious in any of them. CONCLUSIONS: This study confirms that a positive approach to diagnosing IBS is a safe policy. Furthermore, routine ultrasound scanning in IBS is unnecessary and could be counter-productive by detecting many minor abnormalities, which can pose further therapeutic dilemmas.

Abdomen↗

Meniscal ossicle.

Meniscal ossicles are rare and may cause diagnostic difficulty on plain radiograph at presentation. Magnetic resonance imaging is useful in detecting meniscal ossicles because their characteristic appearance on MRI can differentiate them from other disease. Arthroscopy can also diagnose the meniscal ossicle, which in our patient appeared as a swelling in the meniscus. If the patient is asymptomatic before the time of diagnosis, removal of the ossicle may not be indicated and, as with our patient, normal function is possible with the ossicle retained.

Adult↗

Synergistic effect of rapamycin and cyclosporin A in the treatment of experimental autoimmune uveoretinitis.

Immunosuppressive drugs currently available for the treatment of autoimmune diseases display a narrow therapeutic window between efficacy and toxic side effects. The use of combinations of drugs that have a synergistic effect may expand this window and reduce the risk of toxicity. We evaluated the combination effect of rapamycin (Rapa) and cyclosporin A (CsA) in an autoimmune disease model of the eye. The dose-effect relationship of Rapa with CsA was measured in vitro on the inhibition of proliferation of retinal S-Ag-primed lymphocytes. A median effect analysis was performed and a combination index (CI) calculated for 50% inhibition of proliferation. Rapa and CsA were markedly synergistic over a wide dose range (lowest CI = 0.31). Calculated dose reduction factors indicated that Rapa could be reduced nine-fold and CsA reduced five-fold when these drugs were used in combination. These reduced doses were tested in vivo for the treatment of experimental autoimmune uveoretinitis (EAU). Twelve of 15 rats treated with CsA, 2 mg/kg/day, developed EAU with a median severity of 2.5. Fourteen of 15 rats treated with Rapa, 0.01 mg/kg/day, developed EAU with a median severity of 3.25. Complete inhibition of EAU was achieved in all 15 animals treated with the combination of Rapa and CsA (combined vs CsA alone, p < 0.0002; combined vs Rapa alone, p < 0.00001). The demonstrated synergistic relationship between Rapa and CsA will allow the use of reduced doses of each drug to achieve a therapeutic effect. The use of lower doses may reduce the toxicity of these drugs for the treatment of autoimmune uveitis.

Animals↗