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Biomedical subjects

H A Bruining

Publications and source records attributed to H A Bruining.

At least 109 records · Page 6Linked to original sources
PubMed1995

Inhibition of nitric oxide synthesis causes myocardial ischemia in endotoxemic rats.

Inhibitors of nitric oxide (NO) synthesis have been used in the treatment of septic and endotoxic shock. However, several studies question the beneficial effect of inhibiting NO production in sepsis and endotoxemia. We have investigated the effect of inhibition of NO synthesis after endotoxemia in the isolated perfused rat heart. In hearts from endotoxin-treated animals, coronary flow was elevated 64% and oxygen consumption was elevated 20% compared with control hearts. NADH fluorescence imaging was used as an indicator of regional hypoperfusion. A homogeneous low-surface NADH fluorescence, indicative of adequate tissue perfusion, was observed in both control and endotoxin-treated hearts. The increase in coronary flow and oxygen consumption could only partially be prevented by pretreatment of the animals with dexamethasone. Addition of N omega-nitro-L-arginine (NNLA), an inhibitor of NO synthesis, to the perfusion medium eliminated differences in coronary flow and oxygen consumption between normal and endotoxin-treated hearts. However, NADH surface fluorescence images of endotoxin-treated hearts after NNLA revealed areas of high fluorescence, indicating local ischemia, whereas the control hearts remained without signs of ischemia. The ischemic areas were present at various perfusion pressures and disappeared after the infusion of L-arginine, the natural precursor of NO, or the exogenous NO donor sodium nitroprusside. Methylene blue (MB), an inhibitor of soluble guanylate cyclase, the effector enzyme of NO, also eliminated differences in coronary flow and produced similar areas of local myocardial ischemia in endotoxin-treated hearts but not in control hearts.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Oxidoreductases↗
PubMed1995

Differential adaptation of glucocorticoid sensitivity of peripheral blood mononuclear leukocytes in patients with sepsis or septic shock.

In view of the immunosuppressive action of glucocorticoids (GCs), the activation of the hypothalamo-pituitary-adrenal axis in patients with sepsis or septic shock is paradoxical. At the same time, administration of GCs to these patients is not clearly beneficial. We investigated the role of GCs in severe illness by measuring the sensitivity of peripheral blood mononuclear leukocytes to GCs in a mitogen-stimulated lymphocyte proliferation assay. In addition, we studied the role of interleukin-2 and several other cytokines in this system. Cells from patients with sepsis or septic shock (n = 15) were more sensitive to the antiproliferative action of GCs than were cells from normal controls (IC50 6.7 +/- 2.1 nmol/L for patients vs. 19.5 +/- 2.5 nmol/L for controls; P < 0.01). This increased sensitivity of the peripheral mononuclear cells to dexamethasone during the period of sepsis normalized during the ensuing period of clinical recovery of these patients. Dexamethasone inhibited the production of interleukin-2 in the mitogen-stimulated cells. Addition of interleukin-2 antagonized the suppressive effects of dexamethasone in a dose-dependent manner, both in cells from controls and in cells from patients with sepsis. To a lesser extent, the combination of interleukin-1, interleukin-6, and tumor necrosis factor-alpha also counteracted the effects of dexamethasone. In conclusion, our results suggest that not only the activity of the hypothalamo-pituitary-adrenal axis but also the sensitivity to GCs is regulated during sepsis and septic shock. Generally there is an increased sensitivity to GCs, which might help to protect the organism as a whole through supportive effects on metabolism and vasculature. This hypersensitivity is counteracted, possibly at the site of inflammation, by high local concentrations of cytokines. This would enable an adequate local response of the immune system in the presence of elevated cortisol levels. In view of the increased sensitivity of peripheral leukocytes to GCs, treatment of these patients with high doses of GCs may not be beneficial or may even be harmful.

Adult↗
PubMed1995

Use of APACHE II classification to evaluate outcome and response to therapy in acute renal failure patients in a surgical intensive care unit.

The study objective was to determine the applicability of the acute physiology and chronic health evaluation (APACHE) II score in surgical patients with acute renal failure (ARF) requiring dialytic support, and to assess its utility in evaluating data from this specific disease group. This was a retrospective, partly prospective follow-up study of patients who developed ARF during their course of stay on the surgical intensive care unit (ICU) of a Dutch university hospital from January 1, 1986, to January 31, 1994. A total of 111 patients were identified, of whom 104 patients were considered eligible for this study. Data for the individual APACHE II scores were calculated from the most deranged values during the initial 24 h of ICU admission (APACHE II1) and on the day dialytic support was instituted (APACHE II2). The ratio between the two APACHE II scores was also calculated for each patient (AP2/AP1 ratio). Receiver operating characteristic curves (ROC) were constructed. Other variables evaluated included age, sex, serum creatinine, diagnostic category, time from ICU admission to start of dialytic support, and the type of dialytic support. Of these 104 patients (median age 64; range 23-85 years), 51 (50%) survived to leave the ICU, of whom 47 (46%) survived to leave hospital. The APACHE II2 score (27.0 +/- 4.4 vs. 22.4 +/- 3.5; p < 0.001) and AP2/AP1 ratio (1.12 +/- 0.09 vs. 0.97 +/- 0.06; p < 0.001) were significantly higher for nonsurvivors as compared to survivors. The ROC curve was most discriminative for the AP2/AP1 ratio (area under the curve 0.92) and to a lesser extent for the APACHE II2 score (area under the curve 0.78). Estimated risk of death with the APACHE II equation did not improve predictive power. Multivariate analysis of various variables revealed the AP2/AP1 ratio as the single most important factor predicting death (odds ratio 13.8, p < 0.001). Adjusting for the AP2/AP1 ratio, no impact on outcome was observed for age, diagnostic category, time from ICU admission to start of dialytic support, and the type of dialytic support. Above a value of 1.0 of the AP2/AP1 ratio, logistic regression revealed a sharp increase in death probability with increasing AP2/AP1 ratio. APACHE II, when used at the time of initiation of dialytic support, proved to be a valid way in our surgical ICU to stratify ARF patients by the severity of their illness. Moreover, use of the AP2/AP1 ratio further improved the usefulness of this severity index and may help to identify patients who have little chance of survival. Predicting death with the APACHE II equation did not improve predictive power.

APACHE↗
PubMed1994

[Dutch results of the European study of the prevalence of infections during intensive care (EPIIC). I. Who is at risk?].

OBJECTIVE: Evaluation of the point prevalence of infections acquired in an intensive care unit (ICU) and determination of risk factors for ICU patients. DESIGN: Descriptive study. SETTING: 78 Dutch ICUs. METHOD: Collecting data by detailed questionnaires for each patient admitted to one of the participating ICUs, on one specified day: April 29th, 1992. Follow-up lasted 6 weeks. RESULTS: Included in the study were 472 patients; 176 (37%) suffered from an infection, of which 74 (16%) was ICU-acquired. The most important risk factors were: a longer ICU stay (relative risk (RR) 4.23 (95% confidence interval: 3.32-5.40), 99.37 (22.26-434.50) and 146.79 (32.83-656.30) for ICU stays of 3-4 days, 1-2 and more than 3 weeks respectively, in comparison with 0-2 days), correlated with severity of disease (organ dysfunction) and more medical interventions (intubation, urine catheter). The ICU infection risk was lower after elective surgery than after ICU admission without surgery; after emergency surgery the ICU infection risk was higher. During follow-up 63 (14%) patients died. Patients suffering from an ICU infection had a higher mortality risk; the strongest prognostic factor in determining the mortality risk was the APACHE II score (RR: 13 (3.89-42.69) with a score between 16-26 and RR > 100 (7.67-1377.93) with score > 31). CONCLUSION: ICU-acquired infections are a serious problem. Programmes for infection prevention and control need to be adjusted.

APACHE↗
PubMed1994

[Dutch results of the European study of prevalence of infection during intensive care (EPIIC). II. Nature of the infections].

OBJECTIVE: Evaluation of the point prevalence of ICU-acquired infections, the type of infection, the bacteriological cultures and the antibiotics used. DESIGN: Point prevalence study. SETTING: 78 Dutch ICUs, as part of ICUs in 17 West-European countries. METHOD: Collecting data by detailed questionnaires for each patient admitted to one of the participating ICUs, on one specified day: April 29th, 1992. Follow-up lasted 6 weeks. RESULTS: The most frequently diagnosed ICU-acquired infections were pneumonia and infections of the lower respiratory tract (together 63%), followed by urinary tract infections (16%), sepsis (16%) and wound infections (11%). The most frequently cultured pathogens were Gram-negative bacteria (92%), especially Enterobacteriaceae (34%) and Pseudomonas aeruginosa (30%), followed by Staphylococcus (37%), Enterococcus (20%) and surprisingly: 10% fungi. The most-prescribed antibiotics were the cephalosporins (30%), followed by broad-spectrum penicillins (17%), metronidazole (17%) and aminoglycosides (13%). On the day of this survey there was in the Netherlands no infection with MRSA (Methicillin Resistant Staphylococcus aureus), although gentamicin resistant coagulase-negative Staphylococcus and ciprofloxacin-resistant P. aeruginosa were present. In most of the hospitals in the Netherlands, microbiologists, infectious disease specialists (84%) and infection control nurses (51%) take part in the ICU team. Half of the hospitals use selective decontamination. CONCLUSION: ICU-acquired infections are a real threat to the ICU patient. Despite a cautious antibiotics management in the Netherlands, resistance remains a serious problem.

Adolescent↗
PubMed1994

[Preoperative noninvasive tests for localization of enlarged parathyroid glands in 115 patients with hyperparathyroidism].

OBJECTIVE: To evaluate results of preoperative localisation techniques in patients operated for hyperparathyroidism (HPT). SETTING: Rotterdam University Hospital. DESIGN: Retrospective study. METHOD: Results of 4 non-invasive preoperative localisation techniques in 115 patients with HPT were compared with operative findings of 116 explorations. Sensitivity and specificity were calculated for single versus multiple gland disease, primary exploration versus re-explorations and anatomical versus ectopic localisation. RESULTS: Sensitivity of preoperative ultrasound, thallium-technetium subtraction scintigraphy, computed tomography and 99mTc-sestamibi (MIBI) scanning in patients with single gland disease was 56%, 65%, 67% and 83% respectively. In multiple gland disease preoperative localisation techniques were much less successful. For MIBI scintiscanning this question remains unanswered. Specificity of all techniques was high. Success rates of preoperative localisation studies for primary operations and re-explorations were similar. Mean weight of parathyroid tumours that were missed preoperatively was lower than of successfully localised tumours. Only computed tomography and thallium-technetium scintigraphy were able to localise retrosternal parathyroid tumours. CONCLUSION: Review of the literature reveals that there is additional benefit of the preoperative localisation studies in re-exploration for HPT, in contrast to primary exploration. By combining localisation techniques more tumours are visualised. Preliminary results of MIBI scanning are favourable.

Adult↗
PubMed1994

Current role of extracorporeal shockwave therapy in surgery.

In urology the introduction of extracorporeal shockwave therapy brought a revolutionary change to the management of urinary calculi. This inspired the introduction of shockwave therapy in several fields of surgery; it has been applied as a potential alternative to several operative procedures but is still experimental. So far, the major application of shockwave therapy has been lithotripsy of stones in the gallbladder, common bile duct, pancreatic duct and salivary gland ducts. Other applications are in the non-operative management of bone healing disturbances and in the inhibition of tumour growth. Steps towards selective thrombus ablation and pretreatment of heavily calcified arteries have also been made. In this review, the applications of extracorporeal shockwave therapy in several areas of surgery are discussed. It is concluded that, for selected patients, shockwave treatment may serve as a useful addition to the surgical armamentarium.

Calculi↗
PubMed1994

Liver fibrosis after extracorporeal shock-wave lithotripsy of gallbladder stones. A case report.

We encountered significant liver fibrosis in a healthy young patient undergoing laparoscopic cholecystectomy for symptomatic gallstone disease. Twelve months prior to cholecystectomy the patient underwent multiple extracorporeal shock-wave lithotripsy (ESWL) sessions with adjuvant oral bile-acid therapy. Since the site of fibrosis corresponded clearly to the shock-wave transmission path, which was in accordance with animal studies, it was concluded that this liver fibrosis was a side effect of biliary ESWL. Based on these findings and the literature, we conclude that further assessment of the long-term safety of ESWL is still warranted, especially in patients undergoing multiple ESWL sessions.

Adult↗
PubMed1994

Somatostatin receptor scintigraphy: its value in tumor localization in patients with Cushing's syndrome caused by ectopic corticotropin or corticotropin-releasing hormone secretion.

PURPOSE: To assess the feasibility of somatostatin receptor scintigraphy for patients with Cushing's syndrome caused by tumors secreting ectopic corticotropin or corticotropin-releasing hormone (CRH). PATIENTS AND METHODS: Ten patients with Cushing's syndrome, nine with ectopic corticotropin-secreting tumors and one with a CRH-secreting tumor, were consecutively studied. For comparison purposes, eight patients with corticotropin-secreting pituitary tumors and one patient with an autonomous adrenal adenoma were investigated. In vivo tumor localization was performed for all patients using a radionuclide-coupled somatostatin analog. The results obtained with this technique were compared with those obtained with conventional imaging techniques. For some patients, the clinical effects of octreotide therapy were evaluated. RESULTS: Somatostatin analog scintigraphy successfully identified the primary ectopic corticotropin-secreting and CRH-secreting tumors or their metastases, or both, in 8 of 10 patients; in 2 patients with corticotropin-secreting bronchial carcinoids, the tumors could not be visualized. Normal scans were obtained for the 8 patients with corticotropin-secreting pituitary tumors and the one patient with an adrenal adenoma. CONCLUSION: Somatostatin analog scintigraphy can be included as a diagnostic step in the workup of Cushing's syndrome patients with a suspected ectopic corticotropin-secreting tumor or a CRH-secreting tumor.

ACTH Syndrome, Ectopic↗
PubMed1994

Radiographic features of oral cholecystograms of 448 symptomatic gallstone patients: implications for nonsurgical therapy.

Since radiographic findings on oral cholecystography (OCG) have implications for the eligibility for nonsurgical therapy of elderly patients, we investigated the OCGs of 448 symptomatic gallstone patients (109 male, 339 female; mean age, 49.8 +/- 14 (range, 21-88)). Opacification of the gallbladder was found in 323 cases (72.1%). Calcifications of gallstones were found in 85 opacified gallbladders (26.3%). Solitary and multiple stones were calcified in 35.3% and 18.2%, respectively (P < 0.0005). When divided into two groups (< or = 40 years and > 40 years), there was a significant increase in calcifications (P < 0.02) and a non-significant increase in opacification with increasing age. It is concluded that age is a determinant for calcification of gallstones and not opacification of the gallbladder. Since multiple stones are proportionately observed more in clinical studies than in epidemiologic studies, it is suggested that multiplicity of stones predisposes to biliary complaints. That solitary stones are more likely to be calcified than multiple stones, adds to the hypothesis that solitary and multiple stones have a different pathogenesis. Elderly patients, in whom non-surgical therapy is most likely to be indicated and cost-effective, are less likely to be suitable for this form of treatment, since age is a determinant for stone calcification.

Administration, Oral↗
PubMed1994

Bacteriology of selective decontamination: efficacy and rebound colonization.

In earlier studies concerning the use of selective decontamination (SD) we recognized some patients to have an incomplete or failed decontamination which had negative consequences for their outcome. We also experienced patients to have a rebound colonization with potentially pathogenic microorganisms (PPM) after the withdrawal of SD medication, thereby endangering the hospital environment as sources of possibly resistant microorganisms. In a prospective observational cohort-study, we have studied 135 patients on a surgical ICU in a University hospital. On admission 51% of all patients harboured PPM, of which 64% and 79% were eliminated form the oropharynx and gut, respectively. A total of 49 episodes of SD (32%) had to be defined as ineffective, partly due to late or inadequate administration of medication. Rebound colonization with nosocomial aerobic PPM was seen in 20 of 90 successfully decontaminated episodes, but there were no infections. Eighty-four of 123 surveillance cultures (68%) revealed a complete recolonization with flora in a composition not different from the pre-admission flora. Withdrawal of SD medication 5 days after extubation proved satisfactory because no infections ensued. Surveillance cultures are obligatory to determine whether SD is effective as one third of patients receiving SD experienced bacterial colonization with PPM and therefore had no benefit from this prophylaxis. In addition, these results indicate that an intact and functional colonization resistance develops in patients after cessation of effective SD medication, but only when physiological defence mechanisms are presumably restored. In the seven years of experience with SD, increasing antibiotic resistance has not been in the study hospital.

Adolescent↗
PubMed1994

Quality of life after treatment of gallstones: results of a randomised study of lithotripsy and open cholecystectomy.

OBJECTIVE: To compare quality of life after extracorporeal shock wave lithotripsy (ESWL) and open cholecystectomy for symptomatic gallstones. DESIGN: Randomised study. SETTING: University hospital, The Netherlands. SUBJECTS: 49 Patients, 23 of whom were randomized to undergo ESWL and 26 to undergo open cholecystectomy. INTERVENTIONS: Health questionnaires were filled out before, and at 3, 6 and 12 months after treatment. MAIN OUTCOME MEASURE: Improvements of quality of life after one year. RESULTS: Both treatments improved quality of life. Open cholecystectomy improved quality of life significantly better than ESWL (median percentage gains in Nottingham Health Profile scores at 1 year 17.1 and 10.5, respectively, p = 0.003). CONCLUSION: Open cholecystectomy is superior to ESWL in improving quality of life, so cholecystectomy remains the treatment of choice for symptomatic gallstones. For patients who are unfit or unwilling to undergo operation, however, ESWL is adequate because most patients have some benefit from it in terms of quality of life.

Activities of Daily Living↗