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Biomedical subjects

A Paul

Publications and source records attributed to A Paul.

At least 145 records · Page 8Linked to original sources
PubMed1997

Bile acid metabolism by colonic bacteria in continuous culture: effects of starch and pH.

Secondary bile acids (BA) have been shown to be involved as a promoting agent in the adenoma-carcinoma sequence of colorectal cancer. In previous studies, fermentation of starch has been shown to inhibit the degradation of primary to secondary BA by the colonic microflora. This study was designed to investigate BA metabolism in continuous cultures of mixed fecal bacteria to get further insights into the mechanisms of this inhibition. Fermentation vessels were fed with media containing cholic (0.6 g/l) and chenodeoxycholic acid (0.4 g/l). Cultures were either starch-free or enriched with starch (10 g/l). pH was controlled and adjusted to 7.0 or 6.0. Total culture duration was 28 days and concentrations of BA, short-chain fatty acids (SCFA), and starch were measured periodically. At pH 6, significantly more primary BA remained in the media and less secondary BA were produced. Total BA concentrations were lower at pH7. SCFA concentrations were higher in the vessels supplemented with starch. Starch was completely fermented and not present in significant amounts in any fermentation vial after the first week. These data indicate that bacterial breakdown of primary to secondary BA is inhibited when starch is simultaneously fermented. This effect can be explained by the reduction of pH resulting from SCFA production. Considering these findings, resistant starch which escapes assimilation in the small bowel may be a protective factor against colorectal cancer.

Acetates↗
PubMed1997

Waste abatement: recycling, disposal practices can cut costs.

On average, most healthcare facilities are doing less than they should in the areas of source reduction and recycling, and will likely do so until mandated by law. The main reasons for this are ever-tightening healthcare budgets, limited staffing, and the cost of operating recycling programs compared to the cost of general solid waste disposal. Poor record keeping also may also be hampering the final decision to recycle. This article, Part II on waste abatement practices in healthcare organizations, examines what factors facilities should consider in establishing a recycling program, and analyzes cost-effective collection and disposal practices.

Conservation of Natural Resources↗
PubMed1997

[Stomach volume reduction balloon for weight loss: what is the justification for this controversial method?].

UNLABELLED: Overweight and extreme morbid obesity are a common problem in our society. There are many therapeutic options currently available, but none of them can be considered as being ideal. One of these therapeutic interventions is the implantation of an intragastric balloon under endoscopic guidance. PURPOSE: Investigation of the effect of intragastric balloon Implantation on weight reduction. PATIENTS AND METHODS: In a prospective (and in part blinded) study 4 groups of patients (n = 10 each) were evaluated. In group I and II an intragastric balloon was implanted under endoscopic guidance. Group II had an intensive additional therapy by a dietition. Group I was advised to restrict themselves to a 1500 kcal diet. Group III did receive a sham implantation and the same additional therapy as group II. Group IV served as a control group and did not receive any type of treatment except the advice to restrict themselves to a diet. All balloons were explanted after 6 months. The overall follow-up rate was 18 months with a regular control of patients body weight. RESULTS: Patient inclusion criteria were comparable in all 4 groups. After 6 and 12 months a marked weight reduction was observed in group I and II when compared with group III and IV. This weight reduction was stable over time and reached statistical significance after 18 months. Additionally the results of group II (intensive additional therapy by a dietition) were better than in group I. Patients of group IV gained weight. No major complications due to the im- and explantation of the balloon were observed. CONCLUSIONS: The application of an intragastric balloon seems to be effective with regard of weight loss. The patient gets the chance to learn a more effective diet regimen which in our study population had a long lasting effect. Implantation of an intragastric balloon seems to be effective for a selective and highly motivated subpopulation of obese patients.

Adolescent↗
PubMed1997

[Abdominal wall hernias: epidemiology, economics and surgical technique--an overview].

Surgery of the abdominal wall is a chronically neglected field in general surgery. In fact subcutaneous wound infections and incisional hernias are the most frequent events while wound rupture and laparostomy are the most dangerous complications in abdominal surgery. Based on epidemiological data, a classification of adverse events for the abdominal wall is presented. The various currently used techniques for the treatment of incisional hernias are discussed. The described enormous economic consequences of surgical trauma to the abdominal wall alone are already a good reason to improve this kind of surgery in the near future.

Abdominal Muscles↗
PubMed1997

[Current practice of incisional hernia reconstruction in Germany].

The results of a nationwide survey regarding the treatment of incisional hernias following open laparotomy revealed that the Mayo-duplication is the surgical technique preferred by the majority of surgeons. However, in exceptional situations alloplastic material is implanted by up to 50% of the surgeons asked. More than one forth of the departments performed more than 30 incisional hernia repairs per year. Even for complicated cases the surgeons' own estimation of their recurrence rates was 11.7%. Compared with the data (recurrence rate of the Mayo-duplication of 30%-50%) published in the literature there seems to be a quantitative and qualitative underestimation of the treatment of incisional hernias.

Germany↗
PubMed1997

[Mayo duplication in treatment of incisional hernia of the abdominal wall after conventional laparotomy. Results of a retrospective analysis and comparison with the literature].

About 10% of patients undergoing conventional laparotomy will develop incisional hernias. Traditionally these hernias are in this country most often repaired by a Mayo-duplication. In this retrospective analysis we investigated a consecutive series of 114 patients (mean age: 53 (11-87) years, gender ratio m:f 1.2:1.97% electively operated) with 135 hernias, operated between 1/1985 and 12/1992 by a standard Mayo-procedure. Recurrence-rates and quality of life were evaluated by clinical examination. The mean follow-up time was 5.7 (2.5-10.2) years with a follow-up rate of 84.4%. The overall recurrence rate was 53.5%. Further uni- and multi-variate analysis was unable to find any clinically relevant risk factors for hernia development. Health related quality of life was evaluated with a validated index at the time of their follow-up visit. There were no differences in patients without a hernia recurrence (n = 52) when compared to those with an actually present recurrence (n = 36). However, physical function of all patients was significantly impaired when compared to healthy individuals. According to our results and those reported by others the Mayo-duplication when applied to all patients leads to non-acceptable results and implantation of auto- or alloplastic material should be considered more frequently.

Abdominal Muscles↗
PubMed1997

[Auto-dermal hernioplasty--a rare and unknown technique].

The recurrence rates following the "simple" incisional hernia repair procedures (Mayo-procedure or direct adaptation) are unacceptably high, in literature up to 50%. In order to reduce the recurrence rates alternative procedures are necessary, e.g. the additional support of the anterior abdominal wall by implantation of a non resorbable mesh or autodermal plasty. Our national inquiry of 669 hospitals showed that the technique of autodermal hernioplasty is almost unknown among the German surgeons. In this article a comparison of the history, morphology, healing process and possibilities of cutis implantation as well as technical aspects of different types of autodermal hernioplasty (cutis lacing plasty, onlay and sublay corium mesh plasty) are described. By literature analysis the results of autodermal hernioplasty are compared with the results of mesh implantation. The autodermal hernioplasty is discussed as an alternative operative procedure to the implantation of artificial meshs.

Animals↗
PubMed1996

Efficacy of moxidectin 0.5% pour-on against naturally acquired nematode infections in cattle.

The efficacy of 0.5% moxidectin pour-on at two dosages was evaluated in 30 cattle with naturally acquired gastrointestinal nematode infections. The cattle were ranked according to pretreatment fecal egg counts and body weights, and were randomly assigned from replicates to three treatment groups. The mean number of trichostrongyle eggs in pretreatment fecal samples did not differ among the groups. Groups I and II received 0.5% moxidectin pour-on at dosages of 0.25 mg moxidectin per kg body weight and 0.5 mg moxidectin per kg body weight, respectively, and Group III cattle received moxidectin-free vehicle (control cattle). The cattle were euthanized by complete replicate 14 or 15 days posttreatment for recovery of nematodes and examination of the pour-on sites. Treatment with moxidectin was associated with a significant reduction in fecal trichostrongyle egg counts compared with the control cattle; efficacy was 99.7% and > 99.9% for cattle in Groups I and II, respectively. Eleven species of adult nematodes (Haemonchus contortus, Haemonchus placei, Ostertagia ostertagi, Trichostrongylus axei, Trichostrongylus colubriformis, Bunostomum phlebotomum, Cooperia oncophora, Cooperia punctata, Nematodirus helvetianus, Oesophagostomum radiatum and Trichuris ovis) and 4th stage larvae of Ostertagia spp. and Trichostrongylus spp. were present in sufficient numbers in control cattle to evaluate the efficacy of moxidectin 0.5% pour-on. In all cases, treatment was associated with a significant reduction in the number of nematodes recovered at necropsy, with the efficacy of both dosages exceeding 99.9%. There were no significant differences in mean worm burdens or fecal egg counts between the two treated groups, and no adverse reactions were observed.

Abomasum↗
PubMed1996

On the mechanism of the post-activation depression of the H-reflex in human subjects.

It was demonstrated that the soleus H-reflex was depressed for more than 10 s following a preceding passive dorsiflexion of the ankle joint. This depression was caused by activation of large-diameter afferents with receptors located in the leg muscles, as an ischaemic block of large-diameter fibres just below the knee joint abolished the depression, whereas a similar block just proximal to the ankle joint was ineffective. The depression of the H-reflex was not caused by changes in motoneuronal excitability, as motor-evoked potentials by magnetic brain stimulation were not depressed by the same passive dorsiflexion. Therefore it was concluded that the long-lasting depression is due to mechanisms acting at presynaptic level. The transmission of the monosynaptic Ia excitation from the femoral nerve to soleus motoneurones was not depressed by the ankle dorsiflexion. The depression thus seems to be confined to those afferents that were activated by the conditioning dorsiflexion. In parallel experiments on decerebrate cats, more invasive methods have complemented the indirect techniques used in the experiments on human subjects. A similar long-lasting depression of triceps surae monosynaptic reflexes was evoked by a preceding conditioning stimulation of the triceps surae Ia afferents. This depression was accompanied by a reduction of the monosynaptic Ia excitatory postsynaptic potential recorded intracellularly in triceps surae motoneurones, but not by changes in the input resistance or membrane potential in the motoneurones. Stimulation of separate branches within the triceps surae nerve demonstrated that the depression is confined to those afferents that were activated by the conditioning stimulus. This long-lasting depression was not accompanied by a dorsal root potential. It is concluded that the long-lasting depression is probably caused by a presynaptic effect, but different from the "classical" GABAergic presynaptic inhibition which is widely distributed among afferent fibres and accompanied by dorsal root potentials. It is more probably related to the phenomenon of a reduced transmitter release from previously activated fibres, i.e. a homosynaptic post-activation depression. The consequences of this post-activation depression for the interpretation of results on spinal mechanisms during voluntary movements in man are discussed.

Adult↗
PubMed1996

Laparoscopic cholecystectomy for acute cholecystitis: is it really safe?

The prospectively collected data from 530 cholecystectomies performed in a university clinic from October 1989 to March 1991 were analyzed after 1 to 3 years of follow-up. The aim of this study was to compare the results of laparoscopic cholecystectomy (LC) for acute cholecystitis with that for routine symptomatic gallbladders. The preoperative, intraoperative, and postoperative parameters of 424 routine (noninflamed) LCs and 54 LCs for acutely inflamed gallbladders were compared under the "intention to treat" principle. Operating time was longer in the inflamed group (median 97 minutes versus 75 minutes; p < 0.0001). Significantly more adhesions (20% versus 8%), more blood loss (48% versus 19%), a higher incidence of bile spillage (28% versus 12%), and lost stones (19% versus 8%) were encountered in patients with acute cholecystitis. Common bile duct (CBD) injuries were also more frequent in that group (5.5% versus 0.2%; p = 0.005). The rate of conversion to open surgery was higher than with routine LCs (13% versus 4%). There were two deaths in the routine LC group and none in the acutely inflamed group. There was no difference in postoperative pain intensity or postoperative fatigue according to visual analog scale measurements. Patients with acute cholecystitis stayed only 1 day longer (median 4 days versus 3 days) in hospital. The quality of life scores indicate return to almost normal values by the 14th postoperative day. Long-term follow-up (1-3 years) did not reveal any delayed clinical adverse effects. In summary, LC for inflamed gallbladders has a higher conversion rate than LC for routine symptomatic gallbladders. If successfully performed, it has definite benefit for the patient in terms of better postoperative recovery. The trade-off is that the risk of CBD injury is significantly higher.

Acute Disease↗
PubMed1996

The role of protein kinase C in activation and termination of mitogen-activated protein kinase activity in angiotensin II-stimulated rat aortic smooth-muscle cells.

Mitogen-activated protein (MAP) kinases are a family of serine/threonine kinases activated by both tyrosine kinase and G-protein-linked receptor agonists. In rat aorta vascular smooth-muscle cells (VSMC), vasoconstrictors, angiotension II (AII), and alpha-thrombin (alpha-thr), as well as platelet-derived growth factor beta beta (PDGF) stimulated the tyrosine phosphorylation and activation of MAP kinase in a time- and concentration-dependent manner. Pre-treatment of cells with the protein kinase C (PKC) inhibitor Ro-318220, inhibited the initial increase in tyrosine phosphorylation of MAP kinase in response to vasoconstrictors, suggesting the involvement of PKC. Four isoforms of PKC were identified in VSMC by western blotting: alpha, beta, epsilon, and zeta. Downregulation of PKC alpha and PKC epsilon isoforms following chronic phorbol myristate 12, 13-acetate (PMA) pre-treatment resulted in the abolition of AII-stimulated MAP kinase activation. Selective downregulation of PKC alpha following pre-treatment with bryostatin 1 did not affect AII-stimulated MAP kinase. Preincubation of cells with Ro-318220 enhanced the activation of MAP kinase at later time points. In addition, Ro-318220 pre-treatment inhibited the induction by AII of a novel transcriptionally regulated phosphatase, MAP kinase phosphatase-1 (MKP-1). However, AII-mediated activation of MAP kinase was not prolonged by cycloheximide pre-treatment and was not maintained indefinitely by Ro-318220. These results demonstrate a specific role for the Ca(2+)-independent PKC isoform, PKC epsilon, in the activation of MAP kinase in response to vasoconstrictors, and suggest that PKC-mediated induction of MKP-1 plays no role in the termination of transiently activated MAP kinase.

Angiotensin II↗
PubMed1996

Quantitative comparison of excited state properties and intensity- dependent photosensitization by rose bengal.

A quantitative (multistep) excitation-deactivation model of rose bengal (RB) has been developed which includes energy and electron transfer to oxygen and the possibility of photoproduct formation via higher excited triplet-singlet states. The model is based on previous measurements of non-linear absorption (NLA) and emission of RB with picosecond pulses at 532 nm and on NLA measurements with nanosecond pulses. A coupled rate equation and photon transport equation approach for non-linear light-matter interaction is used. The resulting term scheme with all relevant excited state parameters confirms that (i) in the first excited state of RB, relevant absorption at 532 nm takes place only in the triplet, and (ii) the previously reported intensity dependence of RB-sensitized enzyme inhibition is well modelled by the intensity-dependent RB-T1 population and (as the main process) subsequent energy transfer to form singlet oxygen.

Lasers↗
PubMed1996

Effects of L-canavanine, an inhibitor of inducible nitric oxide synthase, on endotoxin mediated shock in rats.

The effects of L-canavanine, an inhibitor of nitric oxide synthase, on endotoxin-induced shock was investigated in the pentobarbitone anesthetized rat. Endotoxin infusion (2.5 mg kg-1 h-1 over 6 h) produced progressive and marked hypotension and hypoglycemia. Electron microscopy showed marked changes in the kidney, comprising severe endothelial cell disruption and the accumulation of platelets in the blood vessels. In the lung, there was marked accumulation of polymorphonuclear leukocytes in small blood vessels and endothelial disruption. Treatment with L-canavanine (10 mg kg-1 by bolus injection each hour starting 70 min after endotoxin or saline infusion) significantly reduced endotoxin-induced hypotension, without any effect on the hypoglycemia. This treatment markedly reduced the endotoxin-induced electron microscopical changes in the kidneys and lungs. Although L-canavanine, like L-NAME, inhibited both cerebellar constitute and splenic inducible nitric oxide synthase in vitro, in contrast to L-NAME it did not modify either arterial blood pressure or carotid artery blood flow in control rats. The data are consistent with L-canavanine being a selective inhibitor of inducible nitric oxide synthase, at least in vivo, and suggest that inhibitors of this enzyme may be beneficial in endotoxin-induced shock.

Animals↗
PubMed1995

Transdermal immunization with large proteins by means of ultradeformable drug carriers.

By means of novel, ultradeformable and self-optimizing agent carriers called transfersomes, large molecules can be brought into the body through intact permeability barriers. This permits non-invasive immunization through normal skin and gives rise to a similar or even slightly higher antibody titer than subcutaneous injections of the same immunogen formulation. The former type of immunization also results in a higher IgA/IgG ratio in the blood than the repeated immunogen injections, as shown here for a soluble protein, human serum albumin, as well as for an integral membrane protein, gap junction protein, in mice.

Administration, Cutaneous↗