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Biomedical subjects

W R Martin

Publications and source records attributed to W R Martin.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Endoscopic study of the small intestine with push enteroscopy. A prospective study].

OBJECTIVE: To evaluate whether push enteroscopy of the small bowel (PES), undertaken after extensive previous investigations in suspected intestinal bleeding from an uncertain site, chronic diarrhoea or lymphoma of the small intestine, contributes to the diagnosis, and to ascertain the results of PES and its clinical significance. PATIENTS AND METHODS: 56 consecutive patients (29 men, 27 women; mean age 63 years) were investigated prospectively. The main indications for PES were the search for the source of intestinal bleeding in 79% of patients (group A), chronic diarrhoea or tropical sprue in 16% (group B) and search for tumour of lymphoma in 5% (group C). PES was always performed in fasting patients under sedation/analgesia using a video PES, which contrary to catheter enteroscopy provides a channel for intervention. RESULTS: In group A 27% of patients were found to have lesions, in particular angiodysplasias, or (in once case) leiomyoma. Half of these patients were successfully treated endoscopically without later surgical intervention being required (mean follow-up of six months). In the other half operation became necessary, either because the disease itself indicated it or the bleeding persisted, the source being in the more distant small intestine and thus not accessible to endoscopic intervention: only 50% of the length of the small intestine proved to be within reach of the instrument. No abnormalities were discovered in patients of groups B and C. CONCLUSION: In cases of gastrointestinal bleeding from an uncertain source PES should be performed first, because in many cases it may obviate surgical intervention. But PES seems to contribute little of diagnostic value in other indications.

Adult↗
PubMed1997

[Percutaneous and transpapillary laser lithotripsy of intrahepatic gallstones].

PROBLEM AND OBJECTIVE: In the last few years several intra- and extracorporeal endoscopic methods have been developed for treating intrahepatic gallstones, but as yet no ideal instrumentation has been found. This study was undertaken to test the efficacy and possible complications of intracorporeal laser lithotripsy for intrahepatic gallstones. PATIENTS AND METHODS: 16 consecutive patients were included (13 women and 3 men, median age 64 [28-82] years) with intrahepatic biliary tract stones which could not be removed by conventional endoscopy. A rhodamine-6G-laser with an integrated stone recognition system was used. The glass fibres of the laser instrument were introduced perorally or percutaneously and placed at the stone. RESULTS: The percutaneous procedure under cholangioscopic control succeeded in four of the patients, while 12 were treated by a transpapillary approach (two under fluoroscopic, ten under cholangioscopic control). In eight of the latter group all stones were completely fragmented, i.e. 12 of the total were successfully treated. Of the remaining four patients two were cleared of stone by additional measures (extracorporeal shockwave lithotripsy and electrohydraulic lithotripsy, respectively), two were treated pallatively by endoprosthesis. One patient developed an acute cholangitis which was successfully treated with antibiotics and biliary drainage. There were no deaths. CONCLUSIONS: Particularly when performed transcutaneously, laser lithotripsy provides effective treatment of intrahepatic gall stones. Cholangioscopic monitoring, to place the glass fibre at the stone, is usually required in the transpapillary approach.

Adult↗
PubMed1997

[Liver abscesses--complications after prosthesis and stent occlusions].

PURPOSE: Patients with malignant, unresectable biliary strictures and endoprosthesis or stents for drainage often develop liver abscess. The aim of the investigation was to assess the relationship and the factors causing the development of these abscesses. METHOD: 9 patients with a median age of 65.6 years, liver abscess and endoprosthesis or stents were studied retrospectively. The occlusions were made visible sonographically and by ERC or PTC. With sonography the abscess was diagnosed and punctured. RESULTS: 5 patients (56%) had a bile duct carcinoma, two patients had a distal tumor stenosis, one a tumor of the gallbladder and one an obstructive jaundice due to liver metastases. 8 patients required a percutaneous drainage (PTCD). 6 cases of occlusions were found. 1 patient had a biliary obstruction because of a broken endoprosthesis. On an average it took 11.6 months from the first endoprosthesis or stent placement to the formation of an abscess. Plastic endoprostheses tend to occlude more rapidly (5 months versus 17.6 with stents). After the sonographically guided puncture of the liver abscess, i.v. antibiotics were given for 5 to 14 days. The antibiotics were continued orally. Two cases required a sonographically placed percutaneous drainage. 78% of the abscesses could be cured. One patient died because of sepsis. CONCLUSIONS: Liver abscesses were connected with intrahepatic carcinomas (56%). In such cases drainage is difficult and requires many interventions. Furthermore, we find this especially after percutaneous transhepatic drainage and with plastic endoprostheses.

Adult↗
PubMed1997

Gender differences in adolescent psychiatric outpatient substance use: associated behaviors and feelings.

OBJECTIVE: To investigate gender differences in substance use and associated high-risk behaviors and feeling states in 220 adolescent psychiatric outpatients. METHOD: One hundred seven females and 113 males with a mean age of 15.6 (SD +/- 1.4), seen in a tertiary care center adolescent psychiatry clinic, completed scales tapping substance use and associated feelings and behaviors. Approximately half had used nicotine and alcohol, one third had used marijuana, and 10% reported narcotic use. RESULTS: Conduct disorder behavior, suicidality, and impulsivity scale scores decreased with age in females while marijuana use, conduct disorder behavior, and Hypophoria scale scores increased with age in males. Alcohol use in males, as contrasted with females, correlated more significantly with other substance use and high-risk behaviors. Suicidality tended to correlate more with polysubstance use in females and with sexual behaviors in females only. Substance use correlated with the Impulsivity and Need scale scores in males and scores on the Sociopathy scale in females. CONCLUSIONS: Substance use in males correlates with high-risk behaviors and is associated with feelings of impulsivity and need. Substance use correlates with self-destructive behaviors and sociopathic feelings in females. There is evidence of more persistent high-risk behaviors, including substance use, in males than in females.

Adolescent↗
PubMed1997

Fluoroscopically guided laser lithotripsy versus extracorporeal shock wave lithotripsy for retained bile duct stones: a prospective randomised study.

BACKGROUND AND AIMS: To compare extracorporeal shock wave lithotripsy (ESWL) and laser induced shock wave lithotripsy (LISL) of retained bile duct stones to stone free rate, number of therapeutic sessions, and costs. PATIENTS: Thirty four patients were randomly assigned to either ESWL or LISL therapy. The main reasons for failure of standard endoscopy were due to stone impaction (n = 12), biliary stricture (n = 8), or large stone diameter (n = 14). METHODS: An extracorporeal piezoelectic lithotripter with ultrasonic guidance and a rhodamine 6G laser with an integrated stone tissue detection system were used. LISL was performed exclusively under radiological control. RESULTS: Using the initial methods complete stone fragmentation was achieved in nine of 17 patients (52.4%) of the ESWL group and in 14 of 17 patients (82.4%) in the LISL group, or combined with additional fragmentation techniques 31 of the 34 patients (91.2%) were stone free at the end of treatment. In comparison LISL tended to be more efficient in clearing the bile ducts (p = 0.07, NS). Significantly less fragmentation sessions (1.29 v 2.82; p = 0.0001) and less additional endoscopic sessions (0.65 v 1.6; p = 0.002) were necessary in the LISL group. There were no major complications in either procedure. CONCLUSIONS: Compared with ESWL, fluoroscopically guided LISL achieves stone disintegration more rapidly and with significantly less treatment sessions, which leads to a significant reduction in cost.

Adult↗
PubMed1997

Management of esophageal perforations after therapeutic upper gastrointestinal endoscopy.

BACKGROUND: Esophageal perforation is one of the most dreaded complications in therapeutic gastrointestinal endoscopy. We assessed the frequency of esophageal perforation after endoscopic procedures in a highly specialized endoscopy unit and compared clinical outcomes in patients undergoing either surgical or conservative management. METHODS: From January 1985 to June 1996, 1011 instrumental endoscopic procedures (dilatation and bougienage) were performed in our department. The computerized complication database was searched to identify all patients with esophageal perforation during this same period, and their records were reviewed. RESULTS: Seventeen esophageal perforations (1.7%) occurred in the course of 1011 procedures. Four perforations resulted from balloon dilatation, and 13 were secondary to bougienage. Six patients were managed surgically (35%), all of them recovering uneventfully. Eleven patients were managed conservatively, mainly because they were unfit for surgery. Survival rate in this group was 82%; only two patients died, both of whom had underlying malignant disease. CONCLUSIONS: The current concept in management of esophageal perforations comprises surgical as well as medical treatment. In well-selected cases, non-operative treatment can be considered with favorable results.

Aged↗
PubMed1997

[Long-term results of endoscopic balloon dilatation of ulcer-induced pyloric stenoses--follow-up of 25 patients].

Long-term results of the "through the scope balloon dilatation" for treatment of benign pyloric stenosis are lacking. Therefore we retrospectively analyzed 25 patients treated by balloon dilatation because of benign pyloric stenosis between 1986 and 1995. The mean age was 63 years (18-88 years), there were twelve men and 13 women. The mean follow-up period was 38 months (twelve to 120 months). 92% (23 patients) underwent successful dilatation. 20% (five patients) presented with recurrent obstruction. They were treated again and none of them has had symptoms up to now. There were no complications due to dilatation. Through the scope balloon dilatation is a successful and cost effective therapy for benign gastric outlet obstruction also in long-term follow-up.

Adolescent↗
PubMed1997

Dysphagia secondary to left atrial dilatation.

Dysphagia, of a cardiac origin, is a generally accepted, yet rarely diagnosed symptom. A 84-year-old female patient with left atrial dilatation, presenting with dysphagia and weight loss, was treated for global heart failure. Esophagography revealed compression of the distal esophagus. Echocardiography showed a left atrial, right atrial and right ventricular enlargement. Esophageal manometry revealed hypotonic peristaltic contractions of the esophageal body and a lower than normal resting pressure of the lower esophageal sphincter. After medical treatment for myocardial insufficiency and of esophageal motility, the clinical signs of global heart failure were improved and the dysphagia disappeared. Following the exclusion of common causes of dysphagia in patients with heart failure, dysphagia due to left atrial dilatation should be considered.

Aged↗
PubMed1996

Basal ganglia iron content in Parkinson's disease measured with magnetic resonance.

The possibility of using magnetic resonance (MR) to evaluate the severity of the pathological changes of Parkinson's disease (PD) is suggested by the known accumulation of iron in the basal ganglia in PD and the reduced signal evident from this area with conventional T2-weighted MR imaging. To improve the specificity of MR for the measurement of tissue iron content, we have developed a method that quantifies the effects of paramagnetic centers sequestered inside cellular membranes, based on the echo time dependence of the decay of transverse magnetization caused by the local field inhomogeneities which are due to intracellular iron. This method enables an index of local tissue iron content to be calculated for structures of the basal ganglia. We report here the application of this method to a series of patients with PD (n = 12) and of normal, age-matched controls (n = 13). Our objective was to determine whether this measurement of basal ganglia iron concentration correlates with the presence and severity of PD. We observed a significant increase in iron content in both the putamen and pallidum in PD as well as a correlation with the severity of clinical symptomatology. More severely affected patients had a higher iron content in both of these structures. Our results suggest that this MR measurement may provide a noninvasive method of measuring the severity of the pathological changes underlying PD.

Adult↗
PubMed1996

Estimation of brain iron in vivo by means of the interecho time dependence of image contrast.

An imaging protocol for a quantitative estimation of disease-induced variations in brain iron is proposed and then validated, first, on a phantom and second, on a group of 11 healthy volunteers. The relative estimate of brain iron is achieved from a rate difference image that measures the enhancement, delta R2app, of the transverse relaxation rate of water protons brought about by the heterogeneous accumulation of iron in the glial cells. At 1.5 T, the phantom study demonstrates, over the range 0-6 A/m, a linear dependence of delta R2app on the magnetization difference between microspheres and a paramagnetic gel, with a sensitivity of approximately 2 s-1 A-1 m. In the group of healthy volunteers (mean age 33 +/- 7 years) devoid of disease-related or appreciable age-related accumulations of iron, the precision of delta R2app was still sufficient to distinguish the globus pallidus and the putamen from all of the other iron-containing brain structures in a manner that was significant at the 99% confidence level.

Adult↗
PubMed1996

-Bile duct stenoses and leakage after cholecystectomy: endoscopic diagnosis, therapy and treatment outcome-.

Minimal invasive methods compete with surgical treatment in the therapy of complications after cholecystectomy. In this retrospective study we evaluate the efficacy of endoscopically placed biliary stents in 35 patients (25 female, ten male) with biliary strictures and/or leakage after cholecystectomy. 27 patients received a 10- or 11.5-French endoprosthesis, eight patients needed a percutaneous-transhepatic-cholangio-drainage (PTCD). Four patients (11.4%) underwent a surgical therapy. Endoscopic therapy was successfully completed in 23 patients (65.7%), at which we noticed a superior result in patients with early incidenced stenosis/leakages after cholecstectomy. During a follow-up period of 1-109 months (median 28 months) two recurrent strictures (5.7%) were observed. As a complication we have seen a prosthesis-dislocation after PTCD. None of the patients died of complications related to endoscopic therapy.

Adult↗
PubMed1995

Brain-plasma distribution of free and total benzodiazepines in dogs physically dependent on different doses of diazepam.

Steady-state levels of oxazepam (OX), nordiazepam (ND), and diazepam (DZ) in plasma, brain tissue, cerebrospinal fluid (CSF), and intracranial microdialysis perfusate were determined in dogs dependent on 0.56, 4.5, 9, and 36 mg/kg per day of DZ. There was a linear relationship between the total plasma and brain levels of DZ, ND, and OX and the chronic dose of DZ. Levels of free benzodiazepines in plasma and CSF and levels in microdialysis perfusates from plasma and brain were significantly correlated. With increasing dependence on DZ there was progressively more free ND and OX and less free DZ in plasma, CSF, and brain. There was a correlation between several signs of precipitated abstinence and free ND in the brain interstitial fluid, whereas convulsions emerged only when free metabolites exceeded free DZ. The changes in contribution of free DZ, ND, and OX to the overall levels of benzodiazepines present in the CNS may explain differences in signs of abstinence for different levels of dependence on DZ.

Analysis of Variance↗
PubMed1995

Functional caudate imaging in symptomatic Huntington's disease: positron emission tomography versus single-photon emission computed tomography.

Functional neuroimaging with positron emission tomography previously demonstrated reduced caudate glucose metabolism in virtually all symptomatic patients with Huntington's disease (HD). Single-photon emission computed tomography studies of brain blood flow also have shown caudate abnormalities in patients with HD. The present study compared these two functional imaging modalities in 6 patients with HD who had been symptomatic for fewer than 5 years. All patients had significantly impaired caudate-thalamus and caudate-whole-slice glucose metabolism ratios as measured by positron emission tomography. However, only 3 had clearly abnormal caudate-thalamus activity ratios and 2 had clearly abnormal caudate-whole-slice ratios on single-photon emission computed tomography. These findings indicate that single-photon emission computed tomography imaging of caudate blood flow is a less sensitive indicator of caudate dysfunction in early HD than is positron emission tomography imaging of caudate glucose metabolism.

Anticonvulsants↗
PubMed1995

Generalized mitochondrial dysfunction in Parkinson's disease detected by magnetic resonance spectroscopy of muscle.

OBJECTIVE: To explore mitochondrial dysfunction in Parkinson's disease (PD) using 31P magnetic resonance spectroscopy of resting muscle. DESIGN: Case-control study (28 PD patients and 28 normal controls) determining resting forearm inorganic phosphate/phosphocreatine (Pi/PCr) ratio. RESULTS: Significant difference (p = 0.004, one-tailed test) in Pi/PCr ratio between PD patients (0.122) and controls (0.104). No correlation of Pi/PCr ratio with duration, severity, or speed of onset of disease. Positive correlation of Pi/PCr ratio with age in control group; reversed in PD group. CONCLUSIONS: Suggests small generalized mitochondrial defect in PD. The possibility that earlier onset of disease is associated with more severe mitochondrial dysfunction needs further study.

Adult↗
PubMed1994

Hyperalgesic and analgesic actions of morphine, U50-488, naltrexone, and (-)-lobeline in the rat brainstem.

Morphine, U50-488, and (-)-lobeline produced dose-related shortening of a low-intensity thermally evoked tail avoidance response (LITETAR) (e.g., hyperalgesia) when microinjected into the dorsal posterior mesencephalic tegmentum (DPMT) of conscious rats. The hyperalgesic potency of (-)-lobeline was greater than either morphine or U50-488. With higher doses, morphine's hyperalgesic actions diminished and prolongation of the LITETAR (e.g., analgesia) was observed. Naltrexone produced analgesia in the DPMT that diminished with increasing dose. The hyperalgesic actions of morphine, U50-488, and (-)-lobeline further suggest the presence of kappaergic opioid and nicotinic mechanisms in the DPMT of rats. The hyperalgesic actions of U50-488, a highly specific opioid kappa-receptor agonist, strongly suggest the presence of a kappa-opioidergic hyperalgesic mechanism in the DPMT.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗