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Biomedical subjects

H R Schmid

Publications and source records attributed to H R Schmid.

17 recordsLinked to original sources
PubMed2005

Shorter PFA-100-closure times in laparoscopic versus conventional hysterectomy are not caused by increased vasopressin levels.

BACKGROUND/OBJECTIVES: Bleeding problems during laparoscopic surgery are infrequent. We hypothesised that increased abdominal pressure during the application of the pneumoperitoneum would lead to an increased release of endogenous vasopressin which could then contribute to the hemostasis by increasing platelet reactivity, FVIII and von Willebrand-factor. PATIENTS AND METHODS: We compared the vasopressin levels, the platelet function as measured by the PFA-100-test, aPTT and FVIII in 39 consecutive patients who underwent elective hysterectomy (20 with the laparoscopic and 19 with the conventional, "open" method). Blood was sampled the day before surgery and 2, 4 and 72 h after the induction of anaesthesia. RESULTS: After two hours, the PFA-100 closure times with collagen/ADP decreased to lower levels in the laparoscopic group (from 93 +/- 22 to 82 +/- 20, mean +/- SD) and even further down to 65 +/- 13 s (compared to 82 +/- 20 s) (p = 0.024)) four hours after the beginning of surgery. Vasopressin levels and F VIII increased in both groups but there was no significant difference between the groups (21 vs. 17.8 pmol/l for vasopressin, differences of the mean). Bleeding was minimal, with a trend to lower Hb-levels in the laparotomy group. CONCLUSIONS: The procedural difference of laparoscopic vs. open hysterectomy appears to enhance platelet reactivity by other mechanisms than increased vasopressin levels and may contribute to an enhanced hemostatic competence in laparoscopic surgery.

Adult↗
PubMed2001

Critical appraisal of the diagnostics of 270 consecutive cases of suspected venous thromboembolism and established consequences at a non-university center.

QUESTIONS UNDER STUDY: Diagnostic strategies in venous thromboembolism (VTE) are subject to controversy and rapid change and are dependent on the availability of the specific tests. The aim was to critically analyse the diagnostic procedures in patients with VTE at an intermediate size, non-university hospital. METHODS: The diagnostic work up of 270 consecutive patients with suspected VTE disorders was analysed prospectively and the therapeutic decisions were monitored and compared with the actually implemented new standard evaluation which consists of a sequential application of the diagnostic tools (clinical probability, D-dimer compression ultrasound V/Q lung scan or CT). The patients were followed clinically for at least three months. RESULTS: 50% of the 55 patients with suspected deep vein thrombosis (DVT) and 35% of the 215 patients with suspected pulmonary embolism (PE) were found positive and were anticoagulated. The overall number of patients being anticoagulated was not significantly changed by the new procedure but approximately 30% of the additional examinations inclusive V/Q-scans, spiral CT and compression ultrasound or phlebography could be saved. Our study and the follow up after the therapeutic decision indicate that 92% of the patients can be clearly and safely allocated, while the remainders are managed according to an essentially clinical decision. CONCLUSIONS: The vast majority (>90%) of the patients can be clearly diagnosed as positive or negative with the strategy presently used. A minority still requires an "overall decision". Our modified approach results in considerable cost savings.

Adult↗
PubMed2001

Prevention of blowfly strike on coarse and fine woolled sheep with the insect growth regulator dicyclanil.

OBJECTIVE: To assess a ready-to-use formulation of dicyclanil to prevent blowfly strike on coarse and fine woolled sheep under New Zealand conditions. DESIGN: Randomized clinical field trials. PROCEDURE: In a first field trial, coarse wooled sheep treated with a ready-to-use, 5% dicyclanil formulation were compared with untreated control sheep for up to 21 weeks. In a second field trial, fine woolled sheep, treated with the same dicyclanil formulation, were compared with untreated sheep for up to 19 weeks. Efficacy was assessed by calculating the aggregated cumulative strike rate. RESULTS: For trial 1 (coarse woolled sheep) the aggregated cumulative strike rate at the end of the trial at week 21 after treatment reached 3.9% and 19.1% for treated and untreated sheep, respectively. For the treated animals the aggregated cumulative strike rate reached the 1% and 2% benchmarks between weeks 11 and 12. For trial 2 (fine woolled sheep) the aggregated cumulative strike rate at the end of the trial at week 19 reached 0.6% and 7.5% for treated and untreated sheep, respectively. Wool length at the time of application did not substantially influence the efficacy of dicyclanil. CONCLUSION: Under New Zealand field conditions, a ready-to-use 5% spray-on formulation of dicyclanil protected coarse woolled sheep for at least 12 weeks and fine woolled sheep for at least 19 weeks.

Animals↗
PubMed2000

Prevention of blowfly strike on lambs with the insect growth regulator dicyclanil.

In three multicentered field trials run during 1995 to 1997, involving a total of 12,928 lambs, the preventive effects on blowfly strike of a ready-to-use 5 per cent dicyclanil pour-on formulation and of a ready-to-use 6 per cent cyromazine pour-on formulation were compared with untreated controls for periods of up to 22 weeks. Their efficacy was assessed by calculating the consolidated cumulative strike rate for each treatment group and the consolidated percentage reduction of flystrike achieved by the two formulations. The consolidated cumulative strike rate for all three years together reached 29.2 per cent for the untreated control lambs at week 22, 2.8 per cent for the dicyclanil-treated lambs at week 22, and 6.9 per cent for the cyromazine-treated lambs at week 20. The consolidated cumulative percentage reduction of blowfly strike remained above 89 per cent for the dicyclanil-treated lambs. For the cyromazine-treated lambs the consolidated cumulative percentage reduction of blowfly strike reached 90 per cent during weeks 9 to 10, and 80 per cent during weeks 11 to 12.

Animals↗
PubMed2000

Excretion pattern investigation of urinary normal and modified nucleosides of breast cancer patients by RP-HPLC and factor analysis method.

Modified nucleosides, formed post-transcriptionally in RNA by a number of modification enzymes, are excreted in abnormal levels in the urine of patients with malignant tumors. To test their usefulness as tumor markers, and to compare them with the conventional tumor markers, a reversed-phase high-performance liquid chromatographic (RP-HPLC) method and a factor analysis method have been used to study the excretion pattern of nucleosides of breast cancer patients. A clear cut differentiation of the breast cancer group and the healthy individuals in two clusters without overlapping was obtained.

Adult↗
PubMed2000

Flystrike prevention on Merino lambs with the insect growth regulator dicyclanil.

The efficacy of a ready-to-use 5% dicyclanil pour-on formulation as a preventative of natural flystrike on Merino lambs was investigated in a field trial involving 5 sites in the southern Cape Province. A total of 1,804 lambs treated with dicyclanil were compared with 882 untreated control lambs for up to 25 weeks after treatment. Efficacy was assessed by calculating the weekly cumulative strike rate at each site and aggregated for all sites, as well as by calculating the percentage reduction achieved in treated lambs. Cumulative strike rates for the untreated controls aggregated for all sites at Weeks 9,14 and 19 after treatment reached 6.2, 12.8 and 17.8%, respectively, compared with 0.4, 1.7 and 3.6% for the dicyclanil treated lambs. Percentage control aggregated for all sites at Weeks 9,14 and 19 after treatment was 93, 87 and 80%, respectively. Heavy rains during the 1st half of the trial did not substantially reduce the efficacy of the product.

Administration, Topical↗
PubMed1999

Field efficacy of the insect growth regulator dicyclanil for flystrike prevention on lambs.

A multi-centered field trial was carried out in the Netherlands to evaluate the efficacy of a ready-to-use 5% dicyclanil formulation as a preventative of natural flystrike on lambs. In four different sites a total of 1215 lambs treated with dicyclanil were compared with 431 untreated lambs during periods of 15 to 16 weeks. Efficacy was assessed by calculating the weekly cumulative strike rate for each site and treatment group and the percentage reduction achieved by dicyclanil. In two of the four sites untreated controls did not receive enough fly challenge and were not considered for efficacy assessment. At the other two sites untreated controls reached cumulative strike rates of 10.5 and 19.5% 15 and 16 weeks after treatment, respectively. None of the 549 lambs treated with dicyclanil at these two sites were struck, resulting in a 100% reduction of flystrike during the whole length of the trial.

Administration, Topical↗
PubMed1999

Long-lasting prevention against blowfly strike using the insect growth regulator dicyclanil.

OBJECTIVE: To assess a ready-to-use formulation of dicyclanil to prevent blowfly strike on Merino sheep under Australian conditions. DESIGN: Randomised clinical trials conducted in an environment house and in the field. PROCEDURE: Two environment house trials were used to measure the protection against flystrike provide by a jetting or a ready-to-use 5% spray-on formulation of dicyclanil over 22 and 31 weeks respectively. Oviposition and strikes were recorded weekly for each sheep. In two field trials the occurrence of strike in Merino sheep treated off-shears or in long wool with dicyclanil or with cyromazine was compared for up to 38 weeks after treatment. Efficacy was assessed by calculating the cumulative percentage of sheep struck. RESULTS: Under environment house conditions, sheep jetted with dicyclanil at 1.50, 0.75 and 0.30 g per sheep developed 0, 8 and 9 strikes respectively during the 22 weeks of the trial, whereas there were 358 strikes present in the placebo group. Sheep sprayed with dicyclanil at 2.25, 1.50 and 0.75 g per sheep developed 5, 11 and 29 strikes respectively between weeks 15 and 31 after treatment, whereas there were 185 strikes present in the untreated controls. In field trials the cumulative percentage of sheep struck reached 1% between weeks 12 to 13 after sheep had been treated with cyromazine. Sheep treated with dicyclanil reached the 1% limit at week 21 after treatment. CONCLUSION: Under Australian field conditions, a ready-to-use 5% spray-on formulation of dicyclanil applied off-shears or to long wool protected Merino sheep from blowfly strike for a period of at least 20 weeks.

Administration, Cutaneous↗
PubMed1997

Quantitation of urinary nucleosides by high-performance liquid chromatography.

It is known that some modified, especially methylated, nucleosides originating from RNA degradation are excreted in abnormal levels in the urine of patients with malignant tumours and they have been proposed as tumour markers. Their measurement could provide a non-invasive diagnostic method, be helpful in the identification of different cancers and in the monitoring of therapeutic effects. In this study, we developed and optimized an analytical procedure to isolate and quantify normal and modified ribonucleosides. The extraction of urinary nucleosides was performed by affinity chromatography on a phenylboronic acid column prior to separation. The reversed-phase high-performance liquid chromatography method allowed a complete separation of sixteen urinary ribonucleosides. The recoveries for the different nucleosides ranged from 83 to 100%, except for xanthosine (66%) and pseudouridine (74%). In normal 24 h urine, the mean levels of thirteen nucleosides (in nmol of nucleoside/mumol of creatinine) were found to be as follows: dihydrouridine (6.37), pseudouridine (25.52), cytidine (0.07), uridine (0.21), 1-methyladenosine (2.19), inosine (0.30), guanosine (0.06), xanthosine (0.59), 3-methyluridine (0.11), 1-methylinosine (1.13). 1-methylguanosine (0.74), adenosine (0.21) and 5'-deoxy-5'-methylthioadenosine (0.12). The first results concerning two kinds of tumours, i.e. breast and floor of mouth tumours, showed some abnormal levels of ribonucleosides. Further experiments are now in progress to measure the modified nucleosides in urine of patients with different forms of cancer.

Adenosine↗
PubMed1996

Predictors of the presence and extent of peripheral arterial occlusive disease.

BACKGROUND: Data relating lipids to the angiographic presence and extent of atherosclerosis, as reported for the coronary circulation, are lacking for the peripheral site. METHODS AND RESULTS: This study comprised 102 patients with peripheral arterial occlusive disease (PAOD) referred for elective percutaneous transluminal angioplasty and 100 age-matched control subjects with normal coronary and peripheral angiograms. The presence of PAOD was defined as > or = 1 stenosis with > or = 50% narrowing, and the extent was defined as the total of > or = 50% lesions in the iliac, femoral, popliteal, and crural beds. The relation of lipids and nonlipid risk factors to the presence of PAOD was tested by stepwise logistic regression analysis; their relation to the extent of disease was analyzed by simple regression and stepwise discriminant analysis. The presence of PAOD was significantly and positively associated with LDL cholesterol (P = .0003), triglycerides (P = .0001), apolipoprotein B (P = .0073), and smoking (P = .005) and was significantly and negatively associated with HDL2 cholesterol (P = .0085) and apolipoprotein A-I (P = .021). In the logistic model, LDL cholesterol, triglycerides, smoking, and systolic blood pressure were selected as independent predictors of PAOD presence. The extent of PAOD was significantly and negatively correlated with HDL3 cholesterol (P = .005), HDL cholesterol (P = .013), and apolipoprotein A-I (P = .021) and was significantly and positively associated with smoking and fasting blood glucose. Age, smoking, and blood glucose were selected by the discriminant analysis as independent predictors of the extent of PAOD. CONCLUSIONS: From this large case-control study, it is concluded that the presence of PAOD is predicted by parameters of LDL, triglyceride, and HDL2 metabolism, whereas the extent of PAOD is related to HDL3 and nonlipid risk factors.

Adult↗
PubMed1995

Lung tumor cells: a multivariate approach to cell classification using two-dimensional protein pattern.

High resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) is a powerful research tool for the analytical separation of cellular proteins. The qualitative and quantitative pattern of polypeptides synthesized by a cell represents its phenotype and thus defines characteristics such as the morphology and the biological behavior of the cell. By analyzing and comparing the protein patterns of different cells it is possible to recognize the cell type and also to identify the most typical features of these cells. In applied pathology it is often difficult to identify the tissue of origin and the stage or grade of a neoplasia by cellular morphology analyzed by classical or immunostaining procedures. The protein pattern itself is the most characteristic feature of a cell and should therefore contribute to the identification of the cell type. For this reason we separated protein fractions originating from different lung tumor cell lines using 2-D PAGE and we compared the resulting patterns on a multivariate statistical level using correspondence analysis (CA) and ascendant hierarchical clustering (AHC). The results indicate that (i) protein patterns are highly typical for cells and that (ii) the comparison of the protein patterns of a set of interesting cell types allows the identification of potentially new marker proteins. 2-D PAGE is thus a unique and powerful tool for molecular cytology or histopathology, unveiling the protein expression level of tissues or cells.

Adenocarcinoma↗
PubMed1993

Effects of enteral infusion of hypertonic saline and nutrients on canine jejunal motor patterns.

The aim of the study was to clarify the effects of hypertonic solutions on jejunal motility. The study focused on differential effects of hypertonic saline and nutrients. Motility of the canine proximal jejunum was recorded with closely spaced strain-gauge transducers. During fasting, hyperosmotic solutions (up to 1520 mosmol/liter) of saline or nutrients (1 kcal/ml) were infused into the proximal jejunum (0.5-1.5 ml/min) up to 6 hr. The hyperosmotic solutions stimulated jejunal motility. With both increasing osmolarity of saline or increasing energy load of nutrients, jejunal motility linearly declined. The reduction of motility was associated with a change in motor pattern from a propulsive to a more segmenting one. Hypertonic glucose evoked a significantly smaller level of motor activity compared with both saline (at given osmolarities) and an elemental diet (at given energy loads). Motility parameters were not different between glucose and maltose, although osmolarity of maltose was less than half (760 vs 1520 mosmol/liter). In contrast, a mixture of glucose-fructose exerted a smaller inhibition of jejunal motility than glucose. The hypertonic solutions of saline or nutrients were tolerated over 2 hr; with hypertonic saline retrograde power contractions with or without vomiting occurred, whereas with hypertonic nutrients vomiting was preceded by strong inhibition of jejunal motility. Three conclusions can be derived from the present results: (1) The behavior of jejunal motility suggested that the motor activity was the result of both a local stimulation and an inhibitory feedback mechanism. (2) The different degree of inhibition between glucose and saline indicated that the nutrient itself played a major role in the inhibitory feedback regulation, whereas osmolarity was of minor importance. (3) Comparisons between different nutrients suggested a linkage between inhibitory control of motility and the absorptive capacity of the gut for the single nutrient.

Analysis of Variance↗
PubMed1990

Propagation velocities and frequencies of contractions along canine small intestine.

This study was performed to clarify in detail the behavior of the propagation velocities and frequencies of contractions along the canine small intestine. In conscious dogs, duodenal, jejunal, and ileal contractions were recorded by multiple, closely spaced strain gauges and analyzed by a computerized method. During both the interdigestive and postprandial states, the propagation velocity increased from the duodenal bulb to the distal duodenum and declined aborally within the jejunum, reaching rather constant values in the ileum. The decrease was steepest in the proximal part of the jejunum. In contrast to the propagation velocities, the contraction frequencies were almost constant in the upper small intestine. In the ileum, the contraction frequencies were markedly lower than in the upper small intestine, indicating that the aboral decrease in frequency occurred in the distal parts of the jejunum. We conclude that both the propagation velocities and the frequencies of contractions decline aborally in a nonlinear fashion. However, the nonlinear patterns of the frequency and the propagation velocity gradients are different.

Animals↗
PubMed1990

Effects of ileal infusions of nutrients on motor patterns of canine small intestine.

In the present study, effects of ileal infusions of nutrients on motor patterns of the proximal small intestine and on gastric emptying were investigated in dogs. An acaloric meal was administered orally, and equicaloric loads of amino acids, oleate, and glucose were infused into the ileum at different doses (0.3, 0.6, and 0.9 kJ/min). The computerized analysis of motor patterns was focused on the differentiation between stationary and propagated contractions recorded by closely spaced extraluminal strain gauges. All three nutrients exerted inhibitory effects on gastric emptying and on contraction force and frequency of the proximal small intestine. Additionally, the propulsive motor pattern induced by the acaloric meal was modulated by reducing the number of contraction waves and their length of spread. All the effects were dose dependent. Among the three nutrients, glucose significantly changed motility at lower doses compared with amino acids and oleate. We conclude that in dogs the ileal brake mechanism is induced by all three nutrients and that it influences not only contraction force and frequency but also the motor patterns of the proximal small intestine.

Amino Acids↗