PubMed Health⌕ Search

Biomedical subjects

R Peter

Publications and source records attributed to R Peter.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Acute compartment syndrome in the post-traumatic leg].

PURPOSE OF THE STUDY: Compartment syndrome represents a clinical entity, whose diagnosis depends both on clinical findings as well as on measurement of the intracompartmental pressure. Physiopathology and clinical aspects of diagnosis and treatment of the acute compartment syndrome are discussed, based on the literature review and personal clinical experience. MATERIAL AND METHODS: We have based our experience on a series of 100 consecutive fractures of the leg, in which we studied mechanism of trauma, fractures localization, timing of surgery for fasciotomy and wound closure. RESULTS: The incidence of compartment syndrome was 8 per cent. Younger age (< 30 years), high energy trauma, or trauma occurring during physical activity appeared to increase the risk of occurrence. Localization of the fracture on the proximal, mid or distal thirds of the leg did not. DISCUSSION: The following aspects are discussed: 1) The perfusion pressure of a compartment is defined as the difference between the diastolic blood pressure and the intracompartmental pressure. 2) Fasciotomy is indicated whenever this value is inferior to 30 mmHg. 3) Failure to measure the pressure within 5 cm from the fracture site may cause underestimation of the compartment pressure. 4) Intramedullary nailing does not seem to increase the risk of compartment syndrome.

Compartment Syndromes↗
PubMed1998

[Fractures of the sacrum and neurologic lesions. Apropos of a case].

Sacral fracture is a difficult diagnosis due to the lack of specific signs and the inaccuracy of conventional radiology. This kind of fracture affects either polytraumatised or aged patients, in whom the fracture can be diagnosed. However these fracture have to be recognized because of their potentially adverse consequences, particularly on neurological structures. The case of a 56 years old man who fell from his height is reported. Two weeks later, due to mild neurologic symptoms, an X-ray and CT of the pelvis were performed, showing a fracture of both sacral alae. A complex neurologic sensitive and motor impairement appeared involving S1 to S5 levels on the left side and L2 to S5 levels on the right side. Many investigations were done to rule out any other etiologic factor of this complex and progressive neurologic deficit. The probable cause was an iterative stretching of the lumbosacral roots ambulating with a floating sacrum fracture.

Humans↗
PubMed1998

[Traumatic lesions of the anorectum].

Injuries of the colon and rectum are common surgical problems. Lesions can be classified into four groups according to the site of damage and the presence of sphincter tears: 1. intraperitoneal perforation without sphincter damage 2. intraperitoneal perforation with sphincter damage 3. extraperitoneal perforation without sphincter damage 4. extraperitoneal perforation with sphincter damage From 1990 to 1998, 11 patients, 7 males and 4 females presenting an anal and/or rectal trauma were admitted in Geneva University Hospital. 8 patients were admitted as an emergency, the 3 others had been transferred to correct an incontinent post traumatic pathology. No mortality. A terminal colostomy was performed in all patients with intraperitoneal injury and in 5 patients with combined extraperitoneal and anal sphincter injury. All sphincter lesions were sutured as an emergency (6 cases). In 3 patients we performed an overlapping sphincteroplasty. 2 patients with persisting incontinence were cured by a dynamic stimulated graciloplasty. The choice of treatment of anorectal trauma includes broad spectrum antibiotherapy, cleaning of the rectum, sphincter repair. A terminal diverting colostomy and laparotomy must be achieved in case of intraperitoneal injury, large extraperitoneal lesion, severe perineal laceration with or without pelvic fracture.

Anal Canal↗
PubMed1997

Can we predict the outcome of a partial rupture of the anterior cruciate ligament? A prospective study of 43 cases.

The concept of partial rupture of the anterior cruciate ligament (ACL) has been confirmed by arthroscopic examination and palpation. We present a prospective study of 43 patients who were diagnosed arthroscopically as suffering from a partial rupture of the ACL by the same surgeon. The patients followed a rehabilitation protocol and were examined by an independent observer after 5 years. Twenty-five patients had a stable knee, whereas 18 eventually suffered a complete ACL rupture. ACL partial rupture is easily recognizable with arthroscopy, but the quantity and state of the still intact fibres is difficult to assess.

Adolescent↗
PubMed1997

Chronic work stress, sickness absence, and hypertension in middle managers: general or specific sociological explanations?

The issue of differential prediction of health outcomes by sociological models of work stress has received little attention so far. This paper argues, both on theoretical and empirical grounds, that active coping with the experience of chronic work stress is more likely to be associated with physical health consequences of sustained autonomic arousal such as hypertension, whereas passive coping may predispose individuals to withdrawal behavior such as sickness absence from work. Based on data from a cross-sectional study on 189 male middle-aged (40-55, 48.3 +/- 4.6 years) middle managers in a car-producing company in Germany, this hypothesis is tested in the framework of the theoretical model of effort-reward imbalance at work. More specifically, the simultaneous manifestation of high effort and low reward at work, indicative of active coping, is expected to statistically predict the risk of being hypertensive. Conversely, suffering from low occupational rewards in the absence of signs of sustained effort, indicative of passive coping, is expected to predict sickness absence (SA) behavior. Multivariate odds ratios (OR) derived from logistic regression analysis and adjusted for important confounders indicate that three measures of low reward are associated with short-term SA (OR ranging from 3.30 to 9.15), that one measure of low reward is associated with long-term SA (OR: 2.67) and that two measures of low reward are associated with number of SA episodes (OR 4.05 and 6.33), whereas no indicator of high effort at work is significantly associated with SA. On the other hand, the OR of being hypertensive is 5.77 in middle managers who suffer from high effort and low reward simultaneously. In conclusion, a sociological model of work stress which allows for differential prediction of health outcomes according to the important notions of active versus passive coping with work demands finds preliminary empirical support.

Absenteeism↗
PubMed1997

Preclinical activity of trans-indazolium[tetrachlorobisindazoleruthenate(III)] (NSC 666158; IndCR; KP 1019) against tumour colony-forming units and haematopoietic progenitor cells.

Trans-indazolium[tetrachlorobisindazoleruthenate(III)] (KP 1019) is a new heavy metal complex with promising activity against tumour cell lines and in animal models. We studied the antineoplastic effects of KP 1019 (final concentrations: 1, 10, 100 micrograms/ml) on in vitro proliferation of clonogenic cells from freshly explanted human tumours in a capillary soft agar cloning system, and compared the activity of KP 1019 with conventional antineoplastic agents. 53 of 75 specimens (71%) showed adequate growth in controls. KP 1019 inhibited tumour colony formation in a concentration-dependent manner in both short- (1 h) and long-term (21 d) exposure experiments. KP 1019 at 100 micrograms/ml with 1 h exposure was as active as bleomycin, cisplatin, doxorubicin, etoposide, 5-fluorouracil, methotrexate, mitomycin-C and vinblastine, with only paclitaxel more active than KP 1019 (P = 0.002). The antitumour activity of KP 1019 was more pronounced after long-term exposure, indicating the potential schedule dependency of KP 1019. Activity was observed against non-small cell lung, breast and renal cancer. We conclude that if appropriate plasma levels can be achieved in patients, KP 1019 may have significant clinical activity against a variety of different tumour types.

Cell Division↗
PubMed1997

Chronic work stress is associated with atherogenic lipids and elevated fibrinogen in middle-aged men.

OBJECTIVES: To examine the association between a model of chronic work stress (high efforts in combination with low rewards) and two risk factors of coronary heart disease, low-density-lipoprotein (LDL)-cholesterol and fibrinogen. DESIGN: A cross-sectional study in a group of 179 healthy middle-aged (48.5 +/- 4.5) male middle managers. SETTING: A large car-producing enterprise in Germany. RESULTS: After adjustment for relevant covariates, logistic regression analysis showed independent effects of a composite measure of high effort and low reward at work on the prevalence of elevated (upper tertile, i.e. > or = 160 mg dL-1) LDL-cholesterol (prevalence odds ratio (POR) = 3.57; 95% confidence intervals (CI): 1.24-10.20) and on elevated (upper quintile, i.e. > or = 420 mg dL-1) plasma fibrinogen (POR = 6.71 (CI: 1.57-28.76). Apart from this core measure, cigarette smoking, overweight and alcohol consumption were the covariates with the relatively strongest contributions to the multivariate model. CONCLUSIONS: Results give preliminary evidence on an independent association of chronic work stress with atherogenic lipids and with elevated fibrinogen in an occupationally homogeneous group of healthy middle-aged men.

Adult↗
PubMed1996

Efficacy of 5'-nor-anhydrovinblastine (vinorelbine), against freshly explanted clonogenic human tumor cells in vitro.

Vinorelbine (5'-nor-anhydrovinblastine) is a semisynthetic vinca alkaloid currently undergoing extensive clinical evaluation. We have studied the antitumor effect of vinorelbine (final concentrations: 8.4-1000.0 ng/ml) against freshly explanted clonogenic cells from 102 human tumors using a capillary soft agar cloning system and have compared the compound's activity with vinblastine, vincristine, vindesine, paclitaxel, docetaxel, and other clinically used anticancer agents. Four specimens were excluded from further analyses (3 bacterial or fungal contamination, 1 benign histology). Fifty-one of the remaining 98 (52%) specimens had adequate colony formation in control capillaries. Vinorelbine showed concentration-dependent antitumor activity against a variety of solid tumors. At clinically relevant concentrations (0.1 x peak plasma concentrations in humans) vinorelbine inhibited 21 of 49 specimens (43%) and was as active as vinblastine, vincristine, vindesine, bleomycin, doxorubicin, 5-fluorouracil, mitomycin-C, cisplatin, methotrexate, and etoposide. However, paclitaxel (71% inhibition, p = 0.006) and docetaxel (78% inhibition, p = 0.002) were significantly more active than vinorelbine. Moreover, vinorelbine showed antitumor activity against several tumor types and in particular against breast cancer but also in non-small cell lung cancer. We conclude that vinorelbine has a wide spectrum of in vitro activity against freshly explanted human tumors and that the clinical activity of this compound against breast cancer and non-small cell lung cancer is reflected in vitro.

Antineoplastic Agents, Phytogenic↗
PubMed1995

Investigation of the comparative effects of 2-chlorodeoxyadenosine on tumor colony forming units in vitro.

2-CdA is a deaminase-resistant purine analogue which has shown clinical activity against various hematological tumors, and is currently undergoing clinical phase II trials. The objectives of our study were to determine the activity of 2-CdA against freshly explanted clonogenic cells from non-hematological human tumors and compare this agent with other clinically useful anticancer agents. We also compared short-term (1 hour) and long-term (21-28 days) exposures. For short-term exposure (1-hour), final concentrations were 0.57, 5.7, 57, and 114 ng/ml. Inhibition of tumor specimens was concentration-dependent: 0.57 ng/ml: 1/51 (2%), 5.7 ng/ml: 4/52 (7%), 57 ng/ml: 11/52 (21%), 114 ng/ml: 27/50 (54%). At concentrations > or = 57 ng/ml, 2-CdA was as active as cisplatin, doxorubicin, 5-fluorouracil, mitomycin-C, vinblastine, and etoposide. For long-term exposures (21-28 days), final concentration of 2-CdA were 0.57, 5.7, and 57 ng/ml. At 0.57 ng/ml, 2-CdA was active in 4/54 (7%) specimens [5.7 ng/ml: 13/54 (24%), 57 ng/ml: 40/54 (74%)]. A head-to-head comparison with short-term exposures demonstrated greater activity if the drug exposure time was extended. Using the strategy for testing other standard agents (in vitro dose of 1/10th achievable peak plasma concentration), one would predict clinical response rates for single agent bolus or short-term administration of 2-CdA to be in the neighborhood of 7%. Longer durations of infusion or multiple doses might increase the response rate to about 24%. If higher peak plasma concentration could be achieved, dose-dependent increases in clinical responses might be achievable. We conclude that 2-CdA is active against clonogenic cells from freshly explanted non-hematological human tumor specimens at high concentrations.

Antineoplastic Agents↗
PubMed1994

D-dimer plasma measurement in patients undergoing major hip surgery: use in the prediction and diagnosis of postoperative proximal vein thrombosis.

Plasma D-Dimer (DD), a highly sensitive marker of venous thromboembolism, was measured with an ELISA assay preoperatively and on the 12th postoperative day in 173 patients undergoing major hip surgery (78 elective arthroplasties and 95 operations for fractures). Proximal deep venous thrombosis (DVT) was detected by systematic compression venous ultrasonography on the 12th postoperative day in 12 (7%) patients. In one additional case, proximal DVT was diagnosed by venography. Preoperative DD level was significantly higher in patients with fracture than in patients undergoing elective arthroplasty. At a cutoff of 500 micrograms/L as determined by ROC curve analysis, the sensitivity, specificity, positive and negative predictive values of the pre-operative DD concentration for the development of subsequent proximal DVT were 93%, 23%, 36% and 96%, respectively. The diagnostic exclusion value of the DD measurement on the 12th postoperative day was similar but for a cutoff of 2000 micrograms/L. These data suggest that plasma DD measurement might be useful to predict and diagnose proximal DVT following major hip surgery.

Adult↗
PubMed1994

Screening for proximal deep venous thrombosis using B-mode venous ultrasonography following major hip surgery: implications for clinical management.

Despite antithrombotic prophylaxis, deep vein thrombosis (DVT) remains a frequent complication following major hip surgery. Most of the postoperative DVTs are asymptomatic but may result in fatal pulmonary embolism. Thus, detection of these events remains a clinical challenge. The present study evaluated prospectively the clinical usefulness of a systematic screening for proximal DVT in 173 consecutive patients undergoing major hip surgery and given systematic antithrombotic prophylaxis. On the 12th postoperative day, real-time B-mode ultrasonography of lower limbs veins detected 12 patients (7%) with proximal DVT. None of the individual or surgical characteristics of the patients could help to predict postoperative DVT. Because the sensitivity of ultrasonography for diagnosing DVT in asymptomatic patients may be low and because we did not screen for distal DVT, it was speculated that up to half proximal DVT and up to 75% of all DVT might have been missed by the screening. Therefore, low-dose oral anticoagulation with an INR 1.5-2.0 might be the most cost-effective modality in the postoperative period after the initial perioperative prophylaxis with low-dose heparin, low-molecular-weight heparins or intermittent pneumatic compression boots. Oral anticoagulant treatment might be continued for a total duration of 6 weeks, thereby also providing efficient therapy of undiagnosed distal DVT and prolonged for 3 months in patients with proximal DVT proven by systematic ultrasonographic screening at the time of discharge. The benefit-to-risk ratio of this management strategy deserves further evaluation in a specially designed, prospective trial.

Adult↗
PubMed1993

Sudden unconsciousness during local anesthesia.

This case demonstrates the necessity of adequate emergency management during dental treatment. A 57-year-old man loses consciousness immediately after the injection of a dental local anesthetic. For medical assistance, a neighboring general practitioner is first telephoned without success. After approximately 15 minutes, an ambulance is telephoned, but the caller gave no indication of the situation being life threatening. Finally, an emergency doctor is dispatched and arrives approximately 35 minutes after the emergency situation began. The electrocardiogram shows a supraventricular tachycardia which, after an immediate cardioversion, converts to a sinus rhythm connected with a restoration of the circulatory function. This case exemplifies the consequences of an inadequate response to a sudden emergency.

Anesthesia, Dental↗
PubMed1993

Treating tibial fractures with a modified Sarmiento method.

There is still no unanimous agreement on the appropriate primary treatment of tibial fractures. One fraction advocates conservative treatment, and another advocates open reduction and internal fixation. Between these extremes is the functional treatment developed by Augusto Sarmiento. The authors adopted Sarmiento's method in 1976 and present a prospective study of 317 cases treated between 1976 and 1988 in which the union rate was 98.7%. They describe the Sarmiento method as ideal for closed, spiroid (whether comminuted or not) tibial fractures resulting from low-energy forces.

Adolescent↗
PubMed1992

The role of hypertension, left ventricular hypertrophy and psychosocial risks in cardiovascular disease: prospective evidence from blue-collar men.

Epidemiological studies have demonstrated that, compared with the population as a whole, there is increased cardiovascular morbidity and mortality among lower socio-economic groups. To explore determinants of the increased risk within this group, a prospective 6.5 year investigation of a cohort of 416 middle-aged (40.8 +/- 9.6 years) male blue-collar workers was undertaken. In addition to established somatic and behavioural risk factors, psychosocial influences that measured chronic occupational stress in terms of an imbalance between high effort and low reward were assessed. Multivariate logistic regression analysis shows that hypertension (odds ratio (o.r.) 3.85; 95% CI 1.59-9.34), left ventricular hypertrophy (o.r. 3.62; 95% CI 1.06-12.37), hyperlipidaemia (o.r. 2.55; 95% CI 1.08-6.00), status inconsistency (measuring low reward at work) (o.r. 2.86; 95% CI 1.04-7.80) and 'immersion' (measuring high intrinsic effort at work) (o.r. 3.57; 95% CI 1.22-10.47) independently contribute to the prediction of fatal or non-fatal cardiovascular events (acute myocardial infarction, stroke). Expected probabilities of cardiovascular events are clearly elevated if the combined effects of left ventricular hypertrophy and psychosocial risks are analysed. In conclusion, increased incidence of cardiovascular disease among lower socio-economic groups is explained by a co-manifestation of established risk factors including left ventricular hypertrophy (by ECG) and psychosocial factors measuring chronic stress at work.

Adult↗
PubMed1991

Identification and determination of the two principal metabolites of minocycline in humans.

A chromatographic method has been developed for the quantification of minocycline in human serum and urine. The chromatographically determined concentration of minocycline correlated well with the microbiologically active concentration in serum. Two metabolites, 9-hydroxyminocycline and N-demethylated minocycline, could be isolated and identified as the principal metabolites of this tetracycline antibiotic. The structure of the 9-hydroxy compound was proved by nuclear magnetic resonance analysis for the first time. About 15% of the drug was actively converted in the body into a substance less microbiologically active than the parent compound and excreted in the urine within 96 h after the application.

Adult↗
PubMed1991

Phase I/pharmacokinetic reevaluation of thioTEPA.

Because the initial evaluation of N,N',N''-triethylenethiophosphoramide (thioTEPA) preceded the standardized approach to the Phase I trials, uncertainty surrounds the recommended dose. Since it has recently been demonstrated that an almost 100-fold increase in dose can be administered in bone marrow transplant regimens, we conducted a Phase I reevaluation of thioTEPA. ThioTEPA was administered i.v. in 50 ml 5% dextrose in water over 10 min. Twenty-seven patients were entered at doses ranging from 30 to 75 mg/m2. The major toxic effect was myelosuppression; thrombocytopenia greater than or equal to grade 3 occurred in four of seven patients, and leukopenia greater than or equal to grade 3 in two of seven patients at 75 mg/m2. Among eight patients at 65 mg/m2 only two had greater than or equal to grade 3 myelosuppression making this the recommended new phase II dose for the majority of patients. Moderate (grade 2) easily controlled nausea and vomiting was the only other major side effect. There was no alopecia or mucosal or neurological toxicity. Three partial remissions were observed among nine previously treated ovarian cancer patients. Plasma concentrations of thioTEPA and its major active metabolite triethylenephosphoramide (TEPA) were measured by gas chromatography. The half-life of thioTEPA ranged from 51.6 to 211.8 min, and its pharmacokinetics was dose dependent; total body thioTEPA clearance decreased with increasing dose. The half-life of TEPA was considerably longer than that of the parent compound (3.0 to 21.1 h); as a result, the area under the plasma concentration-time curve (AUC) of TEPA was severalfold greater than that of the parent compound. The ratio of TEPA AUC to thioTEPA AUC decreased with increasing dose, suggesting that formation of TEPA is a saturable step in elimination. The AUC and total body clearance of thioTEPA, but not of TEPA, were closely correlated with neutrophil but not platelet toxicity.

Dose-Response Relationship, Drug↗
PubMed1991

[Cigarette smoking and psychosocial work stress in middle-management employees].

The association between psychosocial work stress and cigarette smoking is analyzed in a socioeconomically and professionally homogeneous group of 163 middle managers (40-55 years; 48.4 +/- 4.5) in a large industrial company. Psychosocial stress is defined in terms of an imbalance between effort spent and reward obtained at work. The relative risk of regular smoking is 4.34 (odds ratio after controlling for age; 95% CI 1.50-12.54) in those middle managers who suffer from a marked imbalance between effort and reward, compared to those who are free from this type of psychosocial stress at work. This effect persists in the older age group although the proportion of smokers decreases with age. Within the group of regular smokers, every second middle manager suffering from a marked imbalance between effort and reward is a heavy smoker (greater than or equal to 20 cigarettes/day) whereas in the group experiencing less stress at work, only 28% heavy smokers are found. However, due to small numbers this difference is not statistically significant. In conclusion, the data reported in this study demonstrate an association between psychosocial stress at work in terms of high effort and low reward and the risk of regular smoking. This association is not confounded by age, socio-economic status or type of occupation.

Administrative Personnel↗