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Biomedical subjects

W R Martin

Publications and source records attributed to W R Martin.

At least 19 recordsLinked to original sources
PubMed2001

[DNA cytometric studies of Barrett mucosa].

BACKGROUND: Barrett's esophagus predisposes to cancer development. The diagnosis of dysplastic precursor lesions is impaired by problems of subjectivity. In the present study, DNA ploidy results of patients with Barrett's esophagus were related to the grade of dysplasia and to the progress of the disease. PATIENTS AND METHODS: In 61 patients with Barrett's esophagus, DNA ploidy was determined by image cytometry on imprints. All biopsies (n = 145) were histologically examined for dysplasia distinguishing between low- and high-grade dysplasia, and dysplasia-negative. RESULTS: A significant correlation (p < 0.001) between DNA ploidy and the grade of dysplasia was found, with 81% euploid DNA results in biopsies negative for dysplasia and 86% abnormal DNA patterns in biopsies with high-grade dysplasia. The subgroup of low-grade dysplasia showed a heterogeneous DNA ploidy. It is important to note that nearly 20% of biopsies classified dysplasia-negative contained abnormal single cells or abnormal stemlines regarding DNA content. In several cases, suspect DNA results caused a modified reclassification of dysplasia, and there were cases in which patients negative for dysplasia but positive for abnormal DNA ploidy developed dysplasia later on. CONCLUSION: In patients with Barrett's esophagus, DNA ploidy by image cytometry is a suitable additive method for histological evaluation of dysplasia. It seems to be helpful in identifying patients at risk, perhaps before the development of clear dysplasia.

Aneuploidy↗
PubMed2001

Endoscopic papillary balloon dilation vs. sphincterotomy for removal of common bile duct stones: a prospective randomized pilot study.

BACKGROUND AND STUDY AIMS: Endoscopic sphincterotomy (EST) is the standard procedure for gaining access to the common bile duct for removal of bile duct stones. However, the procedure is associated with both short-term and long-term complications. Recent reports have described the use of endoscopic papillary balloon dilation (EBD) as an effective and safe alternative to EST. We conducted a prospective randomized pilot study to compare the efficacy and short-term complication rates of these two established methods for removing uncomplicated bile duct stones. PATIENTS AND METHODS: Sixty patients were randomly assigned to receive either EST (n = 30) or EBD (n = 30) prior to removal of bile duct stones (maximum size 20 mm, maximum number five). The patient groups were comparable with regard to sex and age ratios, the size of the stones (EST: mean 10 +/- 4.7 mm; EBD: mean 7 +/- 3.5 min; not significant) and the numbers of stones (EST: mean 1.8 +/- 1.5 mm; EBD: mean 1.6 +/- 1.1 mm; not significant). EBD was carried out using a balloon-tipped biliary catheter (Maxforce, Microvasive, Boston, Massachusetts, USA) with a maximum diameter of 24 Fr for 45-60 s. Bile duct stones were removed using Dormia baskets or retrieval balloons, or both. RESULTS: The two methods were successful in all patients studied. Subsequent stone removal was possible in all 30 patients after EST (100%) and in 23 of the 30 who underwent EBD (77%), respectively (P<0.01). After conversion to EST, complete bile duct clearance was also achieved in the remaining seven EBD patients. The mean duration for the whole procedure was 17 +/- 12 min for EST and 29 +/- 15 min for EBD (not significant). Complications (WHO grades 2-4) were observed in five of the 30 EST patients (three cases of mild pancreatitis, two of hemorrhage) and in nine of the 30 EBD patients (three cases of cholangitis, four of mild pancreatitis, and two of severe pancreatitis), showing a trend toward higher complication rates in the EBD group. Postintervention hyperamylasemia was observed in six patients (three in each group). CONCLUSIONS: The results of this prospective randomized pilot study indicate that EST is superior to EBD in terms of stone removal, duration of the procedure, and complication rates. EST will therefore continue to be the standard procedure for stone removal in the near future. Further studies will be needed in order to compare the longer-term results with EST and EBD.

Adult↗
PubMed2001

Magnetic resonance imaging and spectroscopy in Parkinson's disease.

At present, conventional MR imaging shows no convincing structural changes in PD itself but may be useful in helping to distinguish PD from other neurodegenerative parkinsonian syndromes and from the occasional case of parkinsonism secondary to a focal brain lesion. MR spectroscopy may also provide useful information in distinguishing PD from disorders such as MSA. The general field of MR imaging and spectroscopy is evolving rapidly, and there are a number of areas in which we can expect new developments to provide relevant information. Novel pulse sequences may provide more information regarding substantia nigra pathology in PD. The use of MR as a tool to measure regional iron concentrations should provide more information regarding the relationship between iron accumulation and parkinsonian symptoms. MR spectroscopy provides a sensitive tool for the researcher to investigate in vivo the possible contribution of abnormalities in brain energy metabolism to the pathogenesis of PD. Spectroscopy also allows the assessment of other metabolite changes in PD, for example, providing for the evaluation of the potential importance of changes in regional brain glutamate content. Last, although not considered in the present review, functional MR imaging provides the potential to evaluate, in a noninvasive fashion, the role played by the basal ganglia in motor control and in cognition in normal individuals as well as in PD.

Brain↗
PubMed1999

Ropinirole and pramipexole, the new agonists.

Ropinirole and pramipexole are non-ergoline dopamine agonists which are relatively specific for the D2 family of dopamine receptors. They have side-effect profiles linked to peripheral and central dopaminergic stimulation, amenable to tolerance through a slow titration or the addition of domperidone in sensitive patients. They do not have the uncommon but problematic ergot-related side effects of bromocriptine and pergolide. Ropinirole and pramipexole have both been shown to be efficacious when used as monotherapy in early Parkinson's disease (PD), and have been suggested as being less likely than levodopa to lead to the early development of motor fluctuations and dyskinesias in this clinical setting. They have also been shown to be useful as adjunctive therapy to levodopa in advanced PD and to have a levodopa-sparing effect in these patients. Dose equivalents amongst the available dopamine agonists is difficult to know with certainty but has been estimated as follows: 30 mg of bromocriptine, 15 mg of ropinirole, 4.5 mg of pramipexole, and 3.0 mg of pergolide.

Animals↗
PubMed1999

Wrestling.

Wrestling is considered one of the most physically demanding sports among high school and college athletics and, as such, has a proportionate number of injuries. Strength and endurance is paramount to successful performance. The wrestler needs to have not only strength and endurance, but also technical skill to be successful. Weight control and weight loss distinguish it from most other sports at the high school and collegiate levels. In addition to musculoskeletal problems, medical conditions and diseases impact the ability if the wrestler is to safely participate in this demanding but rewarding sport.

Asthma↗
PubMed1999

Prevalence and clinical importance of Helicobacter pylori infection in patients after partial gastric resection for peptic ulcer disease. A prospective evaluation of Helicobacter pylori infection on 50 resected patients compared with matched nonresected controls.

UNLABELLED: There have been only a few surveys on the prevalence of persistent Helicobacter pylori (Hp) infection in patients who have undergone surgery for peptic ulceration. The aim of the study was to evaluate the prevalence and clinical importance of Hp infection after partial gastric surgery due to peptic ulcer disease. METHODS: We examined 50 patients who had partial gastric resection for peptic ulcer disease and years later underwent upper gastrointestinal (GI) endoscopy. 50 controls matched with respect to indication for GI endoscopy, age and gender were also studied. Three specimens from the fundus of gastric remnant were examined for Hp infection (histology and rapid urease test). The prevalence of Hp infection and pathology findings were compared between the two groups using chi-square statistics. RESULTS: 32 men and 18 women were examined (40 x BII, 10 x BI). The prevalence of Hp infection was 38% in the resected group compared to 60% in the control group (p = 0.015). We found a significant association (p = 0.0004) between Hp infection and endoscopic findings in the control group but not in the group of partially resected patients (p = 0.66). CONCLUSION: The prevalence of Hp infection in hospitalized patients with partial gastric resection is significantly lower than in matched controls. Hp infection does not play a significant pathogenic role in recurrent ulcer after partial gastric resection in these patients.

Adult↗
PubMed1999

The prevalence of motor neurone disease in the Province of Alberta.

Using data from the Alberta Health Care Insurance Plan, the prevalence of motor neurone disease (MND) was estimated for the Province of Alberta, Canada. Between January 1, 1994 and December 31, 1995, 208 cases of MND (125 males, 83 females) were identified from physician billing records giving a period prevalence of 7.38 (8.9 for males, 5.9 for females) per 100,000 population. On prevalence day, July 1, 1995, there were 171 cases (103 males, 68 females) of MND giving a point prevalence estimate of 6.07 (7.3 for males, 4.8 for females) per 100,000 population. Males were more likely to be diagnosed (OR = 1.52, 95% CI 1.1, 2.1) with MND and there was an increased risk of receiving a diagnosis with increasing age (chi 2trend = 281, p < 0.001). The mean age of the cases was 59.2 years (58.5 for males, 60.3 for females) and did not differ significantly between the sexes. Geographically, there was no statistically significant difference in the prevalence across regions of the Province. During the study period, 28% of the cases had died (30% of males, 25% of females). The prevalence of MND in Alberta, is among the highest reported in the literature and requires additional investigation to verify these estimates and identify possible causative factors.

Adult↗
PubMed1999

[Treatment of Barrett esophagus with argon plasma coagulation with acid suppression--a prospective study].

26 patients with a Barrett's esophagus of at least 2 cm length (medium 4.9 cm) were treated with a combination of repeated argon-plasma-coagulation (APC) and a long-term acid suppression using proton pump inhibitors controlled by a 2 h pH monitoring. Eleven out of 26 patients (42%) showed endoscopically and histologically a complete eradication of the metaplastic cylindric epithelium (intention--to treat analysis). Nine patients (35%) had an endoscopic complete remission but remnants of the cylindric epithelium were found at the histologic examination. On an average one APC-session was necessary for 1 cm of initial length of the Barrett's esophagus. No serious complications were seen. It remains unclear if this therapy can reduce the long-term risks for adenocarcinoma of the esophagus in patients with Barrett's esophagus.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1999

Electrohydraulic lithotripsy treatment of gallstone after disimpaction of the stone from the duodenal bulb (Bouveret's syndrome).

A 75-year-old man with right upper quadrant abdominal pain was diagnosed by gastroscopy to have an impacted gallstone in the duodenal bulb. Using the polypectomy loop, the stone was extracted from the bulbus and mobilized into the stomach. After failure to remove the stone from the stomach as well as fragmentation by mechanical lithotripsy, electrohydraulic lithotripsy was used to break up the stone, parts of which passed spontaneously through the bowel. Thus, it was unnecessary to proceed with surgical enterolithotomy to remove, from the duodenal bulb, the impacted gallstone responsible for the gastric outlet obstruction.

Aged↗
PubMed1998

Increasing striatal iron content associated with normal aging.

Free-radical-mediated mechanisms may contribute to neuronal damage in Parkinson's disease (PD), other neurodegenerative conditions also associated with aging, and the aging process itself. Cytotoxic free radicals are generated in the brain by oxidation/reduction reactions that are catalyzed by transition metals such as iron. Any regional increase in brain iron concentration may increase the potential for local free-radical formation. The purpose of this study was to determine the relationship between age and basal ganglia iron content in 20 normal individuals ranging from 24 to 79 years of age. We used an in vivo magnetic resonance method to quantify the effects of paramagnetic centers sequestered inside cellular membranes, thereby enabling the determination of a quantitative index of local brain iron content. We observed a strong direct relationship between age and regional iron content in the putamen (r = 0.76, p < 0.0001) and caudate (r = 0.69, p < 0.001), but not in the globus pallidus (r = 0.32, p = 0.17) or thalamus (r = 0.13, p = 0.58). In conclusion, striatal iron content increases with advancing age. This increase may increase the probability of free-radical formation in the striatum, therefore representing a risk factor for the development of neurodegenerative disorders such as PD in which nigrostriatal neurons may be affected by increased oxidant stress.

Adult↗
PubMed1998

Long-term results (7 to 10 years) of endoscopic papillotomy for choledocholithiasis. Multivariate analysis of prognostic factors for the recurrence of biliary symptoms.

BACKGROUND: The long-term outcome after endoscopic papillotomy is poorly defined. The aim of this study was to determine the long-term results of this method in the treatment of common duct calculi and to determine which prognostic factors are associated with the relapse of biliary symptoms. METHODS: Between 1985 and 1988, 223 consecutive (149 women, mean age 67.9 years) patients underwent endoscopic papillotomy for duct stones; 127 had already undergone cholecystectomy or underwent this operation during the same hospitalization. Follow-up data were obtained retrospectively from the patients and patients' relatives and general practitioners. RESULTS: The procedure was successful in 217 of 223 cases (97%), of which 203 were followed-up; 2 patients died in the first month after treatment (0.89%). Mean follow-up for the 201 patients was 6.2 years, during which 31 relapsed (15%). Three significant prognostic factors for late complications were identified in a multivariate analysis. The recurrence rate of biliary symptoms in patients who were left with an in situ gallbladder was 20.2%, and 11% for those whose gallbladder was removed (p = 0.04). Patients with a bile duct 15 mm or greater in diameter were more prone to recurrence of symptoms than those with a bile duct 10 mm or less in diameter (41% vs. 10%, p = 0.025) and were especially at higher risk to develop recurrent stones (19.5% vs. 4.9%, p = 0.019). Stone recurrence, but not biliary symptoms as a whole, was more frequent in patients with a peripapillary diverticulum (p = 0.035). CONCLUSIONS: The long-term results of endoscopic papillotomy are comparable with those of surgical techniques. The prognostic factors associated with relapse of biliary symptoms as a whole are gallbladder left in situ and choledochal diameter. Bile duct size and peripapillary diverticula are associated with recurrent bile duct stones.

Adult↗
PubMed1998

Increased basal ganglia iron in striatonigral degeneration: in vivo estimation with magnetic resonance.

BACKGROUND: As many as 20% of individuals with the clinical diagnosis of Parkinson's disease (PD) do not have the characteristic neuropathologic features of PD at post mortem. The striatonigral degeneration (SND) subtype of multiple system atrophy is one of the categories of pathology which may be incorrectly diagnosed as PD on the basis of clinical presentation. SND may be associated with increased iron deposition in the putamen which can be detected with magnetic resonance imaging. METHODS: We have estimated regional brain iron content in a patient with probable SND, using a novel imaging method developed in our laboratory, and have compared the results in this patient to those which we have previously reported in patients with PD and in age-matched controls. RESULTS: We observed that putamenal iron content was increased in our SND patient, beyond the 95% confidence limit for inclusion in the PD group, even when considering clinical severity. In contrast, pallidal and thalamic iron were within the PD range. CONCLUSIONS: The demonstration of increased putamenal iron content may be a useful adjunctive investigative procedure in patients with suspected SND.

Basal Ganglia↗
PubMed1998

A new HF current generator with automatically controlled system (Endocut mode) for endoscopic sphincterotomy--preliminary experience.

BACKGROUND AND STUDY AIMS: The main complications of endoscopic sphincterotomy are pancreatitis, hemorrhage, perforation and cholangitis. In a prospective randomized trial, a conventional current generator was compared to a new generator with an automatically controlled cut system (Endocut) for sphincterotomy. The purpose was to establish whether the new device reduces the complication rate of sphincterotomy. Our experiences over the last 2 years with the new HF current generator are described here. PATIENTS AND METHODS: In this study 100 patients were randomly assigned to one of the two generators. The following points were documented in a protocol form: abrupt or continuous cutting; length of papillotomy; complications. RESULTS: There were no significant differences in sex, age or indication for sphincterotomy. Nor were there any significant differences in the length of the sphincterotomy or mild pancreatitis. In contrast, an abrupt opening of the papillary roof was more frequently observed with the conventional generator (18 patients) than with the new device (one patient, P < 0.001). Mild bleeding occurred in two patients with the new unit, but in 13 with the conventional unit (P = 0.002). Moderate or severe bleeds were observed in neither of the two groups. During the subsequent application phase lasting for 2 years, the following complications occurred in a total number of 850 sphincterotomies (EST): pancreatitis 2.8% (one patient died); hemorrhages requiring transfusion 1% (n = 8); concealed perforations 0.3% (n = 3). CONCLUSIONS: According to our experience to date and based on this study, this new HF surgery unit enables performance of controlled, bloodless sphincterotomies. The danger of papillary hemorrhage appears to be reduced. All examiners found the new system to be safer and more convenient.

Electric Power Supplies↗
PubMed1998

Estimation of brainstem neuronal loss in amyotrophic lateral sclerosis with in vivo proton magnetic resonance spectroscopy.

In vivo proton magnetic resonance spectroscopy (MRS) may be used to quantify brainstem neuronal degeneration in ALS because of the neuronal localization of N-acetylaspartate and N-acetylaspartylglutamate, together termed NA, which are estimated with this technique. We measured the ratio of NA to creatine/phosphocreatine (NA/Cr) with proton MRS at 3.0 tesla (T) in a 4.3-cm3 volume in the pons and upper medulla of 12 ALS patients and 17 age-matched control subjects. Brainstem NA/Cr was reduced in ALS versus control subjects (mean +/- SD: 1.57 +/- 0.20 versus 1.95 +/- 0.14; p < 0.0001). Patients with severe spasticity or prominent bulbar weakness had the lowest NA/Cr ratios; those with predominantly lower motor neuron limb weakness had near-normal ratios. We conclude that proton MRS may quantify region-specific neuronal dysfunction in ALS.

Adult↗
PubMed1998

[Percutaneous transhepatic metal stents in therapy of bile duct stenoses].

Treatment of choice for obstructive jaundice of different origin is the percutaneous transhepatic placement of endoprostheses if the endoscopic access fails for technical or anatomical reasons. Expandable metallic stents are generally preferred to plastic endoprostheses because of higher patency rates. Purpose of this study was to retrospectively evaluate the clinical efficiency and the occlusion rates of percutaneous placed metallic stents in 39 patients with malignant and benign biliary obstruction and to compare the results to a review of the literature. Placement of the stents was successful in all cases. Patients were followed-up for a mean of seven months (1-42 months). 54% of the patients had recurrent jaundice after a mean period of seven months (1-38 months). 35% were treated with a second procedure. Since the occlusion rates of percutaneous transhepatic metallic stents increase after six months and follow-up in most studies is short the real occlusion rates must be expected to be higher than reported. Therefore and in view to the high costs indication for the use of metal stents in biliary obstruction should be carefully checked.

Adult↗
PubMed1998

[Barrett esophagus with severe dysplasia in argon beam therapy].

A curative therapy of Barrett's esophagus is not established, yet. However, in prospective clinical research trials, a combined therapy of potent pharmacological acid suppression with superficial coagulation of metaplastic epithelium is examined. By local coagulation using photodynamic therapy, laser or argon plasma coagulation, a complete reconstitution of squamous epithelium should be achieved. We report on a case of a patient with Barrett's esophagus and low-grade dysplasia, who developed high-grade dysplastic cell formations under argon plasma coagulation therapy. As part of a clinical study, the patient was treated over a period of one year monthly. We monitored the result of the therapy over the period of one year with endoscopy, histolgical investigations and DNA image cytometry. Ultimately a decision in favour of a further surgical management was made. The diagnostic instruments to identify patients with a high risk for the development of adenocarcinoma are discussed.

Adenocarcinoma↗