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Biomedical subjects

R Matkowitz

Publications and source records attributed to R Matkowitz.

At least 19 recordsLinked to original sources
PubMed2003

Outcome after laparoscopic adjustable gastric banding, using the Lap-Band and the Heliogast band: a prospective randomized study.

BACKGROUND: A study was performed to assess the usefulness and efficacy of a new type of band (Heliogast) for laparoscopic adjustable gastric banding (LAGB) for the treatment of morbid obesity, compared with the Lap-Band. METHOD: From January to May 2001, a prospective randomized study of 60 LAGB procedures was conducted: group I (n=30), the Lap-Band system (INAMED); group II (n=30), the Heliogast band (Hélioscopie). We implanted the devices using the 2-step technique (pars flaccida to peri-gastric) by laparoscopy. Port systems were placed on the rectus sheath and were fixed by non-absorbable sutures. Follow-up of all patients was a minimum of 12 months. RESULTS: There were no differences in operating-time, intra-operative complications, or weight loss during the first 4 weeks after surgery. However, with increasing time, more complications with the Heliogast band and differences in weight loss favoring the Lap-Band became significant. CONCLUSION: Based on the results of this study, we recommend that new bands have independent clinical evaluation before commercialization.

Adult↗
PubMed2003

Outcome after laparoscopic adjustable gastric banding - 8 years experience.

BACKGROUND: Laparoscopic adjustable gastric banding (LAGB) has been our choice operation for morbid obesity since 1994. Despite a long list of publications about the LAGB during recent years, the evidence with regard to long-term weight loss after LAGB has been rather sparse. The outcome of the first 100 patients and the total number of 984 LAGB procedures were evaluated. METHODS: 984 consecutive patients (82.5% female) underwent LAGB. Initial body weight was 132.2 +/- 23.9 SD kg and body mass index (BMI) was 46.8 +/- 7.2 kg/m(2). Mean age was 37.9 (18-65). Retrogastric placement was performed in 577 patients up to June 1998. Thereafter, the pars flaccida to perigastric (two-step technique) was used in the following 407 patients. RESULTS: Mortality and conversion rates were 0. Follow-up of the first 100 patients has been 97% and ranges in the following years between 95% and 100% (mean 97.2%). Median follow-up of the first 100 patients who were available for follow-up was 98.9 months (8.24 years). Median follow-up of all patients was 55.5 months (range 99-1). Early complications were 1 gastric perforation after previous hiatal surgery and 1 gastric slippage (band was removed). All complications were seen during the first 100 procedures. Late complications of the first 100 cases included 17 slippages requiring reinterventions during the following years; total rate of slippage decreased later to 3.7%. Mean excess weight loss was 59.3% after 8 years, if patients with band loss are excluded. BMI dropped from 46.8 to 32.3 kg/m(2). 5 patients of the first 100 LAGB had the band removed, followed by weight gain; 3 of the 5 patients underwent laparoscopic Roux-en-Y gastric bypass (LRYGBP) with successful weight loss after the redo-surgery. 14 patients were switched to a "banded" LRYGBP and 2 patients to a LRYGBP during 2001-2002. The quality of life indices were still improved in 82% of the first 100 patients. The percentages of good and excellent results were at the highest level at 2 years after LAGB (92%). CONCLUSIONS: LAGB is safe, with a lower complication rate than other bariatric operations. Reoperations can be performed laparoscopically with low morbidity and short hospitalizations. The LAGB seems to be the basic bariatric procedure, which can be switched laparoscopically to combined bariatric procedures if treatment fails. After the learning curve of the surgeon, results are markedly improved. On the basis of 8 years long-term follow-up, it is an effective procedure.

Adult↗
PubMed1990

Intestinal absorption of D-xylose in the early post-operative period.

To assess intestinal absorption in the early post-operative period, portal and subclavian vein catheters were implanted into 8 pigs. For direct d-xylose infusion into the upper small intestine a feeding tube was inserted via a gastrostomy. Four control animals (Group 1) underwent an open and close laparotomy after catheter and tube implantation. Four pigs (Group 2) underwent a standardised ileocoecostomy. At 6, 24, 36, 48 and 72 h after surgery, d-xylose was infused into the small intestine in both groups of animals. After single-dose administration the absorption kinetics were measured in the pre- and post-hepatic blood compartment. With increasing time after operation the rate and extent of d-xylose absorption returned towards normal but there were significant differences in the d-xylose kinetics between the two groups. The absorption kinetics and d-xylose uptake recovered more rapidly in the control group than in those who underwent ileocoecostomy. Effective enteral feeding in controls after 36 h was achieved, but in Group 2 was delayed until 48 h post-operatively. Absorption capacity returned to normal after 48 h in controls and after 72 h in Group 2.

Journal Article↗
PubMed1989

[Studies of solutions with various branched-chain amino acid contents on protein metabolism in the postoperative period. 1. A 15N tracer kinetic animal model for evaluating the effect of parenteral amino acid administration on nitrogen metabolism].

We were able to estimate nitrogen or protein metabolism on the basis of a 15N metabolic model that delivered a high amount of data during a parenteral nutrition period over 72 h. We describe the basic principles of the necessary N or 15N-analyses in blood, as well as in sera, in urine, in tissues of selected organs and in hepatocytes. This 15N-metabolic model allows the estimation of the utilization of amino acid infusion solutions. Because of the great similarity of parameters of the N or protein turnover between man and pig it is possible to provide relevant information for the clinical practice regarding amino acid infusion solutions.

Alanine Transaminase↗
PubMed1989

[15N] ammonium test for liver function diagnosis.

The functional state of the liver can be assessed by oral administration of 15N labelled ammonium chloride (tracer) and subsequent isotope analysis of [15N]urea and [15N]ammonia in urine. Clinical tests based on the ratio of the excess abundances of [15N]ammonia to [15N]urea excreted in urine 3 hours after oral administration of the tracer gave values for patients with liver diseases which differed significantly from these of healthy subjects.

Ammonia↗
PubMed1988

Evaluation of protein metabolism in clinical practice.

The application of stable isotopes creates further possibilities for our understanding of the metabolism. New concepts especially for non-invasive diagnostic procedures could be developed. An important step in our research program was the performing of a 1-year experiment on a volunteer. On the basis of a 10-pool model we received a lot of informations. Based on this knowledge we developed 2 simplified methods for calculating whole body protein turnover. Knowing the problems with whole body protein calculations we intensified our intentions for determining the protein enrichment in organs and isolated cells (hepatocytes), estimating at the same time the precursor pool in the cells. Of special importance was an extensive study, wherein all those 15N-estimations were performed we are able to do up to now. We calculated whole body protein, but especially we studied the enrichment of the cellular protein fractions in hepatocytes, of plasmaproteins, and of the intracellular precursor pool. This study is the base for further tracer investigations.

Animals↗
PubMed1988

[Resorbate kinetics in the pre- and posthepatic blood compartment in the immediate postoperative phase in swine].

Catheters were implanted in the portal vein by the superior mesenteric vein in pigs for valuation of the absorbant kinetics of enterically applied substances in the mesenteric veins. The blood level kinetics after applying 10 g D-xylose into the jejunum was measured continuously simultaneously in the pre- and posthepatic blood compartment 6, 24, 36, 48, and 72 hours after the operative procedure. An enteric resorption of the pentose is provable already 6 hours after the operation, with their utter normalization in the next 36 hours. The differences between the pre- and the posthepatic concentration-time-graphs admits conclusions on the metabolism of the absorbant in the liver.

Animals↗
PubMed1987

[Value of various amino acid mixtures for the treatment of chronic liver damage].

A reproducible liver lesion was caused in 28 pigs by intermittent, intraperitoneal administration of thioacetamide. The morphological degree of the liver lesion was checked by histological investigations (material drawn from the liver by biopsy). During a 3-day infusion period a so-called liver solution (Aminofusin hepar) was given to one group of animals, a normal solution (Infesol) to a second group, and only an electrolyte infusion solution under oral nutrition ad libitum to a third one. The solutions were labelled with (15N) glycine. The amounts of total N, total 15N, 15N with single non-protein fractions, a number of enzymes of 15N incorporated into the liver protein were measured in urine, and the following points were established: 1. The catabolic situation of metabolism is eliminated both by the so-called normal solution and the specific amino acid solution. The two mixtures of L-amino acids thus have a nutritive effect. 2. The toxic liver lesion is an indication for parenteral nutrition. Oral nutrition alone is not sufficient. 3. The so-called liver solution influences the liver metabolism of the protracted liver lesion more than the so-called normal solution does, and considerably more than an electrolyte infusion solution under oral nutrition ad libitum.

Amino Acids↗
PubMed1986

[The intravenous 15N metabolism test in assessing the effect of parenteral feeding on protein synthesis].

It is possible to investigate the influence of parenteral applicated L-amino acids on protein metabolism of whole organism by the help of 15N-tracer technique in this paper described. We can determine the utilization of nitrogen parenteral applicated quantitatively. On the basis of graphical methods the protein synthesis rate can be calculated. We get this from mathematical models, based on 3-pool-model. The calculation bases on 15N-elimination in urine after intravenous infusion of 15N labeled amino acids solution during the time of 24 h (endproduct method). We describe 3 graphical methods, using the so-called values of plateau of cumulative 15N-excess amount (96 h) (plateau method A) or 15N abundance after 24 h (plateau method B) and the slope of the curve of 15N excess, amount at 24 h ('slope' method). By the help of these methods the therapeutical nutritive conceptions can be evaluated.

Amino Acids↗
PubMed1985

A liver-function test using 15N-labelled ammonium chloride.

Malfunction of the liver involves disturbances of urea synthesis and ammonia detoxification. These phenomena became apparent, especially during ammonia loading of patients. The functional state of the liver can be assessed by oral administration of 15NH4Cl and subsequent analysis of 15N-urea and 15N-ammonia in urine by emission spectrometry. Clinical tests based on the ratio of the excess abundances of 15N-ammonia to 15N-urea excreted in urine 3 h after oral administration gave values for patients with liver disease which differed significantly from those for healthy subjects. Absorption disturbances, which often accompany liver diseases, do not influence the effectiveness of the method.

Aged↗
PubMed1985

[Nitrogen and amino acid resorption in the small intestine of growing swine. 1. Animal study method, nitrogen content and amino acid composition of the small intestine chyme by administration of various proteins].

The amount of endogenous N in the chyme at the end of the small intestine and the amino acid composition of the ileum chyme were ascertained with growing pigs with ileorectostomy after feeding qualitatively differentiated protein sources. In dependence on the protein used, distinct differences turned out for some amino acids with regard to their content in the ileum chyme. Bacteriologic and histologic investigations subsequent to the dissection of the test animals showed that - in comparison to the control animals-the functions of the small intestine remained the same during the time of the experiment. The experiment method described appears to be suitable for absorption investigations up to the end of the small intestine of growing pigs.

Amino Acids↗
PubMed1985

[Exocrine pancreas secretion in swine after feeding soybean extract meal].

Exogenous N-secretion of the pancreas was investigated with growing pigs with fistulae in the pancreas. For this purpose the two protein sources toasted and untoasted soybean oilmeal were used. After the feeding of untoasted soybean oilmeal a significant increase of the secretion volume and of protein outpour could be observed in contrast to toasted soybean oilmeal within 24 h. The heat-labile soybean trypsin inhibitor also caused an activity increase of the pancreatic enzymes.

Amino Acids↗
PubMed1985

[Methodological aspects of the determination of nitrogen metabolism parameters from 15N-tracer experiments on swine based on nitrogen metabolism models. 2. Calculation of N metabolism parameters from the time of urinary excretion of 15N].

After a 45-hour infusion of 15N-lysine and 15N-glycine resp. with pigs of 25 kg live weight, the infusion of the tracer was disrupted and a 3-day reduction phase was made part of the experiment. The N-metabolism parameters such as protein synthesis and decomposition quotas were calculated on the basis of the temporal development of 15N-amounts excreted in urine. The labelling and reduction phases were evaluated simultaneously. By means of including the total N-amount of the animal body the balance calculation becomes more stable. The possible influence of the tracer amino acid in connection with the 3-pool-model is discussed on the basis of the ascertained parameters.

Animals↗
PubMed1984

[Protein turnover in liver failure--determination using the stable isotope 15N].

The 15N-tracer technique gives new opportunities to medical research for investigation of normal and pathological nitrogen metabolism. Analysis of 15N kinetic data derived from total nitrogen excretion in the urine allows to calculate quantitatively certain parameters of protein synthesis and protein metabolism. At the same time analysis of serum samples will allow measurement of 15N-nitrogen incorporation into particular protein or non-protein fractions of the plasma. In the study reported here patients with different liver parenchyme lesions (acute hepatitis, chronic active hepatitis, biliary obstruction, cirrhosis of the liver, hepatic coma) were investigated with a standardized 15N-tracer method developed by us. It could be shown, that protein turnover in patients with liver insufficiency is significantly decreased as compared to healthy persons. Decrease of protein synthesis is associated with a still more pronounced decrease of protein catabolism. There are significant differences in dynamics of 15N in patients with hepatic coma as compared to other patients with liver parenchyme disease without portal encephalopathy. Nevertheless, even in hepatic coma 15N incorporation into plasma proteins can be shown. Differences in the 15N elimination kinetics of the non-protein pool between patients with chronic active hepatitis, biliary obstruction and hepatic coma could be found.

Adolescent↗
PubMed1983

[Standardized 15N-tracer method for the assessment of protein metabolism in clinical practice].

A standardized 15N tracer method is described for the assessment of the nitrogen and protein metabolism in healthy and pathological changed organism. The method represents an isotope technical procedure for the application in the clinical research and practice. The single parts of this routine method are: --the clinical preparation of the patient/proband by means of a standardized nutritional regime, --the tracer administration (single dose) and the sampling (urine, blood), --the 15N-tracer technique (sample chemistry, emissions-spectrometric isotope analysis), --the mathematical evaluation of 15N tracer data.

Blood Proteins↗