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Biomedical subjects

M Fried

Publications and source records attributed to M Fried.

At least 73 records · Page 4Linked to original sources
PubMed2000

Role of lipase in the regulation of postprandial gastric acid secretion and emptying of fat in humans: a study with orlistat, a highly specific lipase inhibitor.

BACKGROUND AND AIMS: To investigate the importance of lipase on gastric functions, we studied the effects of orlistat, a potent and specific inhibitor of lipase, on postprandial gastric acidity and gastric emptying of fat. METHODS: Fourteen healthy volunteers participated in a double blind, placebo controlled, randomised study. In a two way cross over study with two test periods of five days, separated by at least 14 days, orlistat 120 mg three times daily or placebo was given with standardised daily meals. In previous experiments we found that this dose almost completely inhibited postprandial duodenal lipase activity. Subjects underwent 28 hour intragastric pH-metry on day 4, and a gastric emptying study with a mixed meal (800 kcal) labelled with (999m)Tc sulphur colloid (solids) and (111In)thiocyanate (fat) on day 5. Gastric pH data were analysed for three postprandial hours and the interdigestive periods. RESULTS: Orlistat inhibited almost completely (by 75%) lipase activity and accelerated gastric emptying of both the solid (by 52%) and fat (by 44%) phases of the mixed meal (p<0.03). Orlistat increased postprandial gastric acidity (from a median pH of 3.3 to 2.7; p<0.01). Postprandial cholecystokinin release was lower with orlistat (p<0.03). CONCLUSION: Lipase has an important role in the regulation of postprandial gastric acid secretion and fat emptying in humans. These effects might be explained by lipolysis induced release of cholecystokinin.

Adult↗
PubMed2000

Colonic masses: detection with MR colonography.

PURPOSE: To assess magnetic resonance (MR) colonography as a method for detection of colorectal masses, with conventional colonoscopy as the reference standard. MATERIALS AND METHODS: MR colonography was performed in 132 patients referred for colonoscopy because of the possible presence of a mass. After rectal filling with a gadopentetate dimeglumine and water enema, T1-weighted three-dimensional gradient-echo MR studies were acquired with the patient in the prone and supine positions. Water-sensitive single-shot fast spin-echo MR images were also obtained. Surface-rendered virtual endoscopic endoluminal views, orthogonal sections in three planes, and water-sensitive MR images were interactively assessed for presence of colorectal masses by two radiologists. RESULTS: MR colonography was well tolerated without sedation or analgesia. MR image quality was sufficient for diagnosis in 127 (96%) patients. Most small (</=5-mm-diameter) masses were overlooked at MR colonography, but 19 of 31 6-10-mm lesions and 26 of 27 large (>10-mm) lesions were correctly identified. For these large masses, MR colonography had a sensitivity of 93%, specificity of 99%, positive predictive value of 92%, and negative predictive value of 98% for detection of masses. CONCLUSION: MR colonography is a promising modality for help in detecting colorectal mass lesions larger than 10 mm in diameter.

Administration, Rectal↗
PubMed2000

Relative contributions of "pressure pump" and "peristaltic pump" to gastric emptying.

The relative contributions to gastric emptying from common cavity antroduodenal pressure difference ("pressure pump") vs. propagating high-pressure waves in the distal antrum ("peristaltic pump") were analyzed in humans by high-resolution manometry concurrently with time-resolved three-dimensional magnetic resonance imaging during intraduodenal nutrient infusion at 2 kcal/min. Gastric volume, space-time pressure, and contraction wave histories in the antropyloroduodenal region were measured in seven healthy subjects. The subjects fell into two distinct groups with an order of magnitude difference in levels of antral pressure activity. However, there was no significant difference in average rate of gastric emptying between the two groups. Antral pressure history was separated into "propagating high-pressure events" (HPE), "nonpropagating HPEs," and "quiescent periods." Quiescent periods dominated, and average pressure during quiescent periods remained unchanged with decreasing gastric volume, suggesting that common cavity pressure levels were maintained by increasing wall muscle tone with decreasing volume. When propagating HPEs moved to within 2-3 cm of the pylorus, pyloric resistance was found statistically to increase with decreasing distance between peristaltic waves and the pylorus. We conclude that transpyloric flow tends to be blocked when antral contraction waves are within a "zone of influence" proximal to the pylorus, suggesting physiological coordination between pyloric and antral contractile activity. We further conclude that gastric emptying of nutrient liquids is primarily through the "pressure pump" mechanism controlled by pyloric opening during periods of relative quiescence in antral contractile wave activity.

Adult↗
PubMed2000

Relationship between increasing duodenal lipid doses, gastric perception, and plasma hormone levels in humans.

Duodenal lipid causes gastric relaxation, CCK secretion, and nausea. Vasopressin has been implicated in motion sickness-related nausea. We hypothesized that increasing doses of lipid enhance gastric relaxation and CCK-vasopressin secretion, resulting in a dose-related exacerbation of nausea. Nine healthy subjects received isotonic saline or lipid (1, 2, or 3 kcal/min, L1, L2, L3) duodenally. Changes in gastric volume, sensations, and plasma hormone levels were assessed during infusions and isobaric gastric distensions. Lipid infusions increased gastric volume, plasma CCK (but not vasopressin) levels, and gastric compliance during distensions, compared with saline. Plasma CCK levels were related to the dose of lipid administered [CCK levels at 30 min (pmol/l), saline: 1.1 +/- 0.2, L1: 1.8 +/- 0.2, L2: 3.0 +/- 0.2, L3: 4.3 +/- 0.6]. During distensions, nausea increased in intensity with increasing doses of lipid [score (where 0 is no sensation and 100 is strongest sensation), saline: 7 +/- 4, L1: 19 +/- 7, L2: 44 +/- 7, L3: 66 +/- 8]; however, no further rise in plasma CCK occurred. Because neither lipid nor distension alone induced significant nausea, we conclude that the interaction between these stimuli together with a modulation by CCK is responsible for the effects observed. Vasopressin is not involved in lipid- and distension-induced nausea.

Adult↗
PubMed2000

Influence of metabolic state and diabetes on the outcome at the end of first year after gastric banding.

BACKGROUND: The influence of metabolic state and the presence of diabetes before surgery on the weight changes following non-adjustable gastric banding, were studied. METHODS: The total of 50 patients referred for gastric banding had the following parameters measured: insulinemia, glycemia, total cholesterol, triglycerides (TAG), dehydroepiandrostendione (DHEA) and its sulphate (DHEA-S), triiodothyronine, thyroxine, and thyroxine-stimulating hormone. We evaluated 28 of these, who completed at least 6 months of follow-up. 12 of these patients had diet-treated non-insulin dependent diabetes mellitus (NIDDM) and 16 were non-diabetics, and 9 of them had a positive family history of NIDDM (FH DM). We compared the change in weight of the diabetics, non-diabetics and those with positive FH DM, at 3, 6 and 12 months after the operation. Multiple linear regression tested the influence of the measured parameters on patients' weight. RESULTS: Weight loss was greatest in the group of patients without a positive family history of diabetes, and lowest in the diabetic group. Due to the high dispersion, differences in the t-test are not significant. When individual factors and their influence on weight development were tested by multiple linear regression, weight loss was greatest in patients with high TAG and low insulin levels and lowest in patients with diabetes or positive FH DM. CONCLUSIONS: Although post-operative weight can be influenced by other factors, eg. psychological ones, it is advisable to test each patient pre-operatively for insulin and TAG levels, and to establish family history of diabetes and presence of diabetes to give an idea of the prognosis of weight change.

Adult↗
PubMed2000

Bariatric surgery in some "Central and East-European (former Eastern bloc)" countries- current status and prediction for the next millennium.

BACKGROUND: Obesity is increasing globally, including in the formerly "Eastern Bloc" countries. METHODS: A survey was made of obesity and bariatric surgery. RESULTS: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. CONCLUSION: Most countries were found to provide inadequate treatment for obesity. The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.

Body Mass Index↗
PubMed2000

Case studies of the hepatitis B patient: a panel discussion.

In recent years, there have been significant advances in the treatment of patients with hepatitis B who are candidates for liver transplantation. This includes the prevention and management of hepatitis B posttransplantation. However, there is no established protocol for treating these patients. Ultimately, the goal would be to have patients HBV-DNA negative pretransplantation and then to prevent HBV recurrence posttransplantation to help ensure their quality of life. Several clinical case scenarios are presented and possible treatment solutions have been suggested. The timing of a transplant is critical due to the risk of viral mutation while the patient is on a nucleoside analogue antiviral agent and waiting for an organ. One successful option might be to start therapy pretransplant and continue it posttransplant. Combination therapy appears to provide the most effective course of treatment. This should include a nucleoside analogue and patients should be covered with hepatitis B immune globulin throughout the course of therapy. Several other variations of combination therapy are discussed, but many clinical issues remain to be resolved. Guidelines for future studies designed to answer these questions are proposed.

Adult↗
PubMed2000

[Fixation of a non-adjustable gastric band using an anterior gastric wall cuff (randomized study)].

We have been concerned with bariatric surgery at the First Surgical Clinic of th General Faculty Hospital, First Medical Faculty, Charles University Prague since 1983. In 1983-1986 vertical gastroplasties were made, between 1986 and 1993 non-adjustable gastric bands were provided by the laparotomic approach. Since 1993 when we were the first to implement a gastric band operation (GB) by the laparoscopic route, this method is used as the standard method. In 1993-1998 we made at the First Surgical Clinic 517 laparoscopic GB operation on account of morbid obesity in patients with a body mass index of 34-49 kg/m2. The group comprised 449 women and 59 men. The most frequent late complication in our group of morbidly obese patients who had a laparoscopically administered GB was in 5.1% enlargement of the proximal pouch above the GB by dilatation of its wall or slippage of the anterior wall proximally under the GB with a subsequent disorder of gastric evacuation and vomiting. We tried to reduce the incidence of this complication by fixing the GB by a cuff made from the anterior gastric wall. To test the effectiveness of the suggested fixation of the non-adjustable GB by a cuff we implemented in 1998-1999 a prospective randomized study in a group of 80 morbidly obese patients divided into experimental group n1-GB + C with the cuff and a control group n2-GB - C without a cuff. We investigated the incidence of the mentioned complication and the changed volume of the pouch above the GB after one year. Endoscopic assessment of the size of the pouch above the GB after surgery and after one year revealed that in group n1-GB + C the mean increase of the pouch volume was 14.6 ml, i.e. 124% of the original size, while in group n2-GB - C the mean increase of the volume was 33.6 ml, i.e. 154.1% of the original size (p < 0.001). Based on the assembled results and aware of the fact that small groups were involved, we should like to express the assumption that the suggested modification, i.e. fixation of a non-adjustable GB by a cuff made from the anterior gastric wall can reduce the incidence of the complication of slippage of the anterior gastric wall proximally above the bandage.

Adult↗
PubMed2000

[Effect of diabetes in the first year after gastric banding].

Initial hormonal and metabolic investigation was performed in a group o 51 patients (mean age 41 years and body mass index--BMI 45.1 kg/m2) referred to gastric banding for morbid obesity. Patients were followed for one year period after surgery. Using multiple linear regression following parameters influencing BMI change were identified. Negative influence on BMI reduction: high insulin, presence of diabetes, low T3/T4 ratio. Positive influence on BMI reduction high triglycerides level, positive family history of diabetes. It is possible to identify patient's prognosis after gastric banding using metabolic and hormonal investigation. This investigation should be performed in every patient.

Adult↗
PubMed2000

[6 years' personal experience with duodenum-sparing procedures in chronic pancreatitis].

The First Surgical Clinic of the First Medical Faculty Charles University and General Faculty Hospital Prague made operations of the pancreas ever since 1971. In the work sooner or later all approaches to surgical treatment of pancreatitis were reflected. The authors present a brief review of results and their own experience since 1994 when duodenum sparing operations were introduced. Indications for surgical treatment were based on the diagnosis by US, CT and ERCP, in exceptional cases MR, after evaluation by a pancreatologist, roentgenologist and surgeon. The group of patients with chronic pancreatitis was extended by 15 patients from a group operated because of preoperative suspicion of a malignant pancreatic tumour not confirmed during and after surgery. In those Whipple's operation was performed. The same operation was performed in three patients with chronic pancreatitis with serious changes in the area of the head of the pancreas. In 111 patients a drainage and duodenum sparing operation was performed. Of these in 46x according to Neger, 9x according to Frey, 10x modification of these operations, 37x Partington-Rochelle's procedure. The authors did not record postoperative complications after the classical Beger operation and the hospital stay was on average by five days shorter as compared with the classical method of Whipple. When evaluating postoperative complaints and problems (pain, malnutrition, physical constitution and social position) the authors recorded equally favourable results as after non-complicated duodenopancreatectomy. They varied, depending on the patient s co-operation round 87% while after longitudinal drainage of the duct a satisfactory result was recorded in 78% of the operated patients. The authors consider Beger's operation logical because of the removal of the main tissue mass of the head of the pancreas, responsible for pain, complications caused by fibrosis in the area round the bile duct and duodenum, responsible for the deterioration of the compartment syndrome in the left half of the gland. Its result is destruction of the remainder of exocrine and endocrine tissue. Of 170 operated patients one patient with decompensated diabetes died. Based on their own experience the authors do not consider repeated re-operations an absolute contraindication of Beger's operation when conditions permit. A problem is, in their opinion, fibrosis in the vicinity of the pancreas and portal overpressure.

Chronic Disease↗
PubMed1999

Bioassay-directed chemical analysis and detection of mutagenicity in ambient air of the coke oven.

In the present study, we summarize the results of studies on the mutagenic potential of the main fractions and subfractions of extractable organic material (EOM) in the ambient air at the workplaces of the coke oven. The objective of our experiments was to apply the Bioassay-Directed Chemical Analysis (with the use of the Ames test) for the identification of the differences in the mutagenicity of these fractions, in relationship to the complex mixture of EOM in occupational air. From the evaluation of results, it is possible to deduce the following conclusions: (1) The comparison of the mutagenicity in the main fractions (basic, acidic, neutral) demonstrates the existence of differences in mutagenic potential. Of the total mutagenicity, 20.4% is in the basic fraction, 25.4% in the acidic fraction and 54.2% in the neutral fraction. (2) In general, 90.1% of the mutagenicity found in the basic, acidic and neutral fractions together was associated with the requirement of metabolic activation in vitro (+S9). In the case of the neutral fraction, it was 51.8%. (3) These results also suggest that frameshift mutations are the major component (53.8%) of the total mutagenicity of the main fractions. (4) With regards to the mutagenicity of organic compounds in the neutral fraction it appeared that genotoxicants of its subfractions (slightly and moderately polar and aromatic) play the main role. Carcinogenic aromatic hydrocarbons (PAH) and genotoxic nitrocompounds play an important role as determinants of the mutagenic potential of complex mixtures of harmful compounds in ambient air. This is confirmed first by the results of short-term bacterial tests.

Air Pollutants, Occupational↗
PubMed1999

p53-dependent apoptosis or growth arrest induced by different forms of radiation in U2OS cells: p21WAF1/CIP1 repression in UV induced apoptosis.

Following exposure to DNA damaging agents the p53 tumour-suppressor gene induces either a growth arrest (primarily in G1) or apoptosis. The factors governing which response a cell undertakes, however, are unclear. We find that the osteosarcoma cell line, U2OS, (wild-type for p53) is capable of undergoing either p53 dependent apoptosis or cell cycle arrest in response to distinct forms of radiation. Following exposure to UVC, the majority of U2OS cells were apoptotic within 2 days and cells continued to cycle even as viability was being lost. In contrast, after X-ray treatment, U2OS cells exhibited a cell cycle arrest. Western analysis showed that p53 protein was stabilized to a greater extent by UVC than X-ray. Treatment with X-rays induced p21WAF1/CIP1 whereas p21WAF1/CIP1 expression was specifically repressed at the post-transcriptional level after exposure to UVC. Ectopic expression of high levels of p21WAF1/CIP1, which arrested U2OS cells in G1 and G2, initially conferred considerable protection against UVC-induced apoptosis. Ultimately, however, cells underwent apoptosis indicating that a high level of p21WAF1/CIP1 delays but does not block apoptosis. Taken together, these results show that cell cycle arrest and apoptosis can occur in the same cell type in response to different forms of radiation and that the repression of p21WAF1/CIP1 after UVC may contribute to the efficient induction of apoptosis in response to this particular insult.

Apoptosis↗
PubMed1999

[The first decade of routine laparoscopic surgery].

Common use of laparoscopic surgery was extended during the last ten years worldwide, as well as in our Republic. The contribution of laparoscopy to surgery is compared sometimes with the contribution of ether anesthesia. Despite this, discussions persist on the advantages and disadvantages of this method among surgeon as well as physicians from other disciplines, in particular those who indicate patients for laparoscopic operations. The ten-year use of laparoscopy in surgery should be a sufficiently long period for certain general evaluations of the asset of this method. The submitted paper compares some evaluating criteria of laparoscopic surgery and "classical" laparotomic operations. It is obvious that there can be many evaluating aspects and that each aspect has its specific weight. In the submitted paper some of these aspects are compared and discussed with regard to their possible contributions to laparoscopic and laparotomic surgery.

Cholecystectomy, Laparoscopic↗
PubMed1999

[New perspectives in 3D MR colonography].

Filling the colon lumen with contrast allows for 3D-MR-colonography. The 3D data set can be postprocessed to multiplanar reconstruction, surface shaded displays as well as virtual colonoscopy. The latter facilitates the differentiation between haustra and polyps and enables detection of polyps down to 6 mm in size. Multiplanar reconstructions provide the assessment of the inner wall contour. The morphology of the colonic wall itself can be assessed on T1- or T2-weighted images. T1-weighted sequences performed before and after i.v. contrast administration and T2-weighted sequences depict pathologies based on their contrast uptake respectively on their tissue water content. This concept of colonic imaging practicable in less than 15 minutes is useful for the assessment of inflammatory disease, for polyp detection as well as for tumour staging.

Colonic Diseases↗
PubMed1999

Assessment of gastric motor function during the emptying of solid and liquid meals in humans by MRI.

Gastric emptying and motility have previously been assessed by magnetic resonance imaging (MRI) using liquid test meals. The aim of this study was to extend the applicability of our MRI method to the assessment of gastric emptying and motility of solid meals. Gastric emptying and motility of a liquid and a solid meal, of similar chemical properties, were studied in eight volunteers. The MRI protocol combined a multislice turbo spin-echo (TSE) sequence (volume scan, resolution: 1.5 mm) and a dynamic FFE sequence (motility scan, 1 sec/image, resolution: 3.1 mm). Gastric emptying of the liquid meal was faster than emptying of the solid meal when considering half-times of emptying. However, during the first 15 minutes after ingestion, the liquid meal emptied more slowly. This was related to reduced motility with the liquid meal. In conclusion, with our MRI method it is feasible to assess gastric emptying and motility of liquid and solid meals.

Adult↗