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1.
A retrospective study is accomplished in Iceland to study whether mortality and cancer incidence among male physicians (1,210) were lower than those among men of the general population and lawyers (1,032). Overall mortality among lawyers was similar to that of the general male population, however, mortality among the physicians was lower than that of the general population and the lawyers, due to lower mortality for all cancers (SMR 0.73), cerebrovascular diseases (SMR 0.53) and respiratory diseases (SMR 0.54). The physicians had higher mortality for suicide committed by drugs, solid or liquid substances. Cancer was not as frequent among the physicians as among the lawyers, particularly for lung cancer, the SIR was 0.45, but the rates were higher for cancer of the colon and brain among the physicians than among others.  相似文献   

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3.
Vinyl fluoride (VF) is an inhalation carcinogen at concentrations of 25 ppm or greater in rats and mice. The main neoplastic lesion induced in rodents was hepatic hemangiosarcomas, and mice were more sensitive than rats. In a first set of experiments, groups of three rats or five mice were exposed to VF in a closed-chamber gas uptake system at starting concentrations ranging from 50 to 250 ppm. Chamber concentrations of VF were measured every 10-12 min by gas chromatography. Partition coefficients were determined by the vial equilibration technique and used as parameters for a physiologically based pharmacokinetic (PBPK) model. Mice showed a higher whole-body metabolic capacity compared to rats (Vmax = 0.3 vs 0.1 mg/hr-kg). Both species had an estimated Km of < or = 0.02 mg/liter. The specificity for the oxidation of VF in vivo was determined by selective inhibition or induction of CYP 2E1. Inhibition with 4-methylpyrazole completely impaired VF uptake in rats and mice, whereas induction with ethanol (rats only) increased the metabolic capacity by two- to threefold. The pharmacokinetics of VF were also investigated in vitro. Microsomes from rat and mouse liver were incubated in a sealed vial with VF and an NADPH-regenerating system. Headspace concentrations (10-300 ppm) were monitored over time by gas chromatography. Consistent with the in vivo data, VF was metabolized faster by mouse microsomes than by rat microsomes (Vmax = 3.5 and 1.1 nmol/hr-mg protein, respectively). The rates of metabolism by human liver microsomes were generally in the same range as those found with rat liver microsomes (Vmax = 0.5-1.3 nmol/hr-mg protein), but one sample was similar to mice (Vmax = 3.3 nmol/ hr-mg protein). Metabolic rates in human microsomes were found to correlate with the amount of CYP 2E1 as determined by Western blotting and by chlorzoxazone 6-hydroxylation. It is concluded that the greater metabolic capacity of mice for VF both in vivo and in vitro may contribute to their greater susceptibility to tumor formation. CYP 2E1 is clearly the main isozyme involved in the oxidation of VF in all species tested. VF pharmacokinetics and metabolism in humans may depend upon the interindividual variability in the expression level of CYP 2E1. The excellent correspondence between in vivo and in vitro kinetics in rodents improves. substantially the degree of confidence for human in vivo predictions from in vitro data.  相似文献   

4.
Four types of high-flux hemodialyzers, Primus 2000 (high-flux polysulfone 2.0 m2), Altra-Flux 170 G (cellulose diacetate 1.7 m2), FLX-15 GW (polyester-polymer alloy 1.5 m2) and PAN-85 DX (polyacrylonitrile 1.7 m2) were evaluated in vivo. A total of 12 stable chronic hemodialysis patients participated in the study and each type of dialyzer was tested once in 9 of them. Blood samples for the measurement of BUN, creatinine, phosphate, uric acid, albumin and beta2-microglobulin (beta2M) were drawn before and 5 min after the end of the study dialysis. During dialysis, which was performed in all patients with a blood flow rate of 250 ml/min for 240 min, the dialysate (550-600 ml/min) was collected every hour and samples were drawn for the measurements of all the above substances. The mean total amount of low-molecular substances removed per session by each dialyzer was very close to 19.5 g for urea, 2.0 g for creatinine, 0.9 g for phosphate and 1 g for uric acid. The one-third (30-33%) of the above amounts were removed during the first hour of dialysis. Dialyzers' clearances for creatinine and uric acid were significantly higher in Primus dialyzer comparing to FLX-15 GW (p < 0.05) while the clearance for urea showed a borderline significance (p = 0.055). No difference was found either among Altra-Flux 170 G, FLX-15 GW and PAN-85 DX or between Primus and PAN-85 DX dialyzers. Phosphate clearance did not show any difference among the four dialyzers. The lowest amount of albumin removed per session was 0.75 g by PAN-85 DX and the highest 1.8 g by FLX-15 GW, while the equivalents for beta2M were 80 mg by Altra-Flux 170 G and 142 mg by PAN-85 DX. A significant adsorption of beta2M on these dialysis membranes was indicated by the combination of a satisfactory serum beta2M reduction ratio (post-/predialysis values = 0.52, 0.77, 0.60, 0.55) with a reduced beta2M clearance (23.9, 13.6, 20.2, 25.1 ml/min). During the first hour of dialysis, in comparison to the following time, the highest amounts of albumin and beta2M (expressed as percentage of total) were removed by the Primus 2000 dialyzer. Our results indicate that under conventional conditions small differences in the surface area of the high-flux dialyzers are unimportant regarding the removal of low molecules. However, the composition of the membrane seems to play an important role in the removal of high-molecular substances.  相似文献   

5.
It has been proposed that teenage girls often smoke cigarettes to protect themselves from the impulse to binge eat, with its feared weight-gain consequences, particularly when other measures such as greater dietary restraint have failed. The present study looked at the relationship between body mass index and standardised questionnaire responses concerning smoking, alcohol consumption, moods, weight changes, attitudes to body weight and shape, dietary patterns and menstruation in 1936 British (London) and 832 Canadian (Ottawa) schoolgirls. Data analysis revealed links between cigarette smoking and body weight/shape concerns, and awareness by subjects of these links; there was also a tendency for smokers in these two populations to be overweight but not grossly obese. Smoking was also related at all ages to being postmenarchal. The London population in particular revealed an association between smoking and a weight loss of 7 kg or more at some stage since puberty. Smoking was also linked, in a minority, with regular vomiting undertaken as a further defence against weight gain when overeating had occurred. These associations existed alongside the major and predictable association found between alcohol consumption and smoking. Similarities between the British and Canadian schoolgirls were striking in respect of rank order of reasons given for smoking and consequences of giving it up. Since smoking amongst older women is reportedly associated with below-average body weight it may indeed be effective in helping to curb weight gain. Our study provided little evidence of association between smoking and generalised anxiety or social anxiety (in either population), or depression (in the British cohort). We suggest that any preventive psychological approach to teenage female smoking should include attention to weight gain anxiety and consequent pursuit of thinness.  相似文献   

6.
The influence of sex, pregnancy and parturition of biological accumulation and metabolic fate was studied in Sherman rats. 3H-epinephrine was used as a tracer to determine differences in metabolite formation in normal males and females as well as pregnant rats from 18 days post coitum to the end of parturition. The disappearance of 3H-epinephrine and its metabolites was measured in blood, heart, kidney and brain at different intervals but 20 min after the injection of tracer was found the most appropriate time to find appreciable radioactivity in most of the organs studied. All the comparisons for 3H-epinephrine accumulation and its transformation to metabolites have been reported 20 min post-perfusion period. Marked changes of high statistical significance in 3H-epinephrine accumulation and its transformation to 3H-metanephrine and 3H-acid metabolities were observed between males and females. Heart, adrenals, and spleen showed lower rate of metabolism but higher rate of accumulation during pregnancy. Kidney, ovary, and uterus demonstrated higher rate of metabolism but lower rate of accumulation during gestation. In brain regions, hypophysis discriminated greatly between males and females for the three parameters studied. There were important alterations in metabolite formation during 18 and 21 days of pregnancy. The observed variations have been considered due to modified endocrine activity during pregnancy and parturition.  相似文献   

7.
The binding characteristics of saxitoxin (STX), a known voltage-gated sodium channel blocker, and its analog saxitoxinol (STXOL), were studied in neuroblastoma, peritoneal macrophage, hepatocytes and PC-12 cell lines. 3H-STXOL bound to the cell-surface sites which appear to be the same as those occupied by 3H-STX and which can, therefore, be identified as STX receptors. The relative agreement of respective Kd obtained by saturation, competition, association and dissociation kinetics for STX and STXOL suggest the absence of any artifact in binding measurements. Unlike STX, STXOL was non-toxic to mice by intratracheal instillation. The major advantage of using 3H-STXOL is that the tritium label is not exchangeable. Data from this study suggest that 3H-STXOL can be used to identify STX receptors at 37 degrees C.  相似文献   

8.
The response of P. falciparum to chloroquine and pyrimethamine-sulfadoxine in vivo and chloroquine and amodiaquine in vitro was investigated in parasitaemic school children from six locations. Mean parasite sensitivity to chloroquine at day 7 was 74% (range 61-97) with parasite clearance rates between 2-3 days and complete defervescence in 85% of febrile children. Sensitivity declined in the four sites followed up to day 14 to 45% (range 37-53). Parasites were significantly more sensitive to pyrimethamine/sulfadoxine at 5/6 sites (100% day 7) but 5% of subjects became parasitaemic by day 14. In vitro isolates were significantly less sensitive to chloroquine than to amodiaquine with a mean 99% effective concentration of 348 mumol/L compared to 6.44 mumol/L. Clearly the role of chloroquine as the primary therapy for uncomplicated P. falciparum malaria should be reconsidered especially in the light of increasing disease severity and resurgence. Amodiaquine may be suitable alternative with pyrimethamine/sulfadoxine as second line and for more severe malaria prior to referral. The cost of alternative antimalarials and the dynamic and deteriorating pattern of resistance are powerful arguments for more objective slide diagnosis to minimise drug pressure and a regular drug sensitivity surveillance system. We believe that the latter should concentrate on measuring clinical drug efficacy in symptomatic outpatients rather than in asymptomatic children while the former needs more pragmatic and economical strategies possibly centred on seasonality and risk.  相似文献   

9.
Methods were developed for the demonstration and determination of perchlorethylene and petrol in rendered fats and meals for feeding purposes. The methods are based on the collection and the vapours of extracting media over samples of rendering-plant products and on their identification and determination by gas chromatography. Under the conditions of the method, the limit of perchlorethylene extractibility is 0.05% and the limit of petrol extractibility is 0.01% (weight). Under adapted conditions the two limits can be reduced. The reproducibility of the results at practically occuring concentrations of residues in products is characterized by the value of the variation coefficient which reaches 2.79 in perchlorethylene and 6.05 in petrol. The maximum duration of the analysis of one sample is five minutes. In all media have been demonstrated to be present. Their content was high and considerably variable in the fats from rendering plants; in meat-bone meals from petrol extraction the content of residues reached only trace values. It is recommended to use the presented analytic methods for thorough and regular objective control of the residues of extracting media in the products of rendering plants for feeding purposes.  相似文献   

10.
The benefit to the antenatal care from using estriol and human placental lactogen (hPL) determinations is emphasized and likewise that special attention must be paid to values below the reference intervals. Referring to biosynthesis and place of production, a survey is given of the various causes of low estriol and/or low hPL values, and a number of clinical cases illustrate the matter. A follow-up study of children from pregnancies with low estriol values has disclosed an alarming number of cases of severe handicaps.  相似文献   

11.
The question of whether thread- and tangle-like inclusions of the choroid plexus (known as Biondi inclusions) are related to the cortical lesions in Alzheimer disease (AD) has been debated for almost a century, yet remains unanswered. Recently beta-amyloid protein was biochemically isolated from the plexus, indicating a possible pathogenetic relationship between the degenerative changes of the cerebral cortex and those of the plexus. The goal of the present study was to analyze whether or not a significant correlation exists between the occurrence of the cortical AD-type changes and those in the ependyma and choroid plexus. In 292 consecutive autopsy cases several cortical areas, the ependyma, and the choroid plexus were analyzed to look for AD-type changes and Biondi inclusions using histochemical staining techniques and immunohistochemistry. A semiquantitative analysis of the density of cortical AD-type changes showed that of the 292 cases, 63 had severe cortical changes, 23 moderate changes, and 142 discrete changes. In 64 cases no plaques or neurofibrillary tangles were found. The number of cases with thread- and tangle-like elements in the plexus and ependyma was more than 96% in the 3 groups with cortical AD-type lesions, but low in the group without AD-type cortical changes (19%). The pathological argyrophilic filaments accumulating in the ependymal layer and plexus had histochemical properties of amyloid and were immunoreactive with antibodies to P component, ubiquitin, fibronectin and Tau protein. They did not react with antibodies to neurofilament proteins. Ultrastructurally, they consisted of densely packed straight and paired helical filaments and closely resembled neurofibrillary tangles and neuropil threads. The highly significant correlation (chi2, p = 0.001; R = 0.85) between the occurrence of AD-type changes in the cortex and those in ependyma and plexus suggests a pathogenetic relationship.  相似文献   

12.
叙述了日本镁工业的发展,日本向国外投资进口镁的情况,统计分析了日本及世界近几年的镁供需状况、消费结构和今后的镁供需预测。调查分析了今后几年世界汽车用镁的发展。  相似文献   

13.
BACKGROUND: The treatment of cholecystolithiasis has changed fundamentally in recent years due to the development of non-surgical techniques (extracorporeal shockwave lithotripsy [ESWL], oral litholysis) and the implementation of laparoscopic cholecystectomy. PATIENTS AND RESULTS: Retrospective analysis of 2270 patients (1649 women, 621 men; age: 47.2 +/- 14 years) presenting with gallstone disorders in a university medical outpatients department between 1988 and 1992 in order to be instructed as to the most suitable therapy method bear witness to the rapid change in therapeutic procedure. Laparoscopic removal of the gallbladder has virtually supplanted conventional cholecystectomy, and within 5 years the proportionate role of ESWL has declined from 21 to 12%. Over the years, the proportion of patients requiring no therapeutic intervention remained constant (at about 20%). The therapeutic recommendations of the "experts" were implemented in almost 80% of cases. The majority of patients were satisfied with the chosen therapeutic approach (surgery: 93.0%, ESWL: 77.6%), although 44% of ESWL-patients and 36% of surgically managed patients reported complaints which persisted even after completion of therapy. Despite unsuccessful ESWL (residual fragments or recurrent stones) 58/95 (61%) of interviewed patients would again give preference to this non-invasive modality in the event of a renewed therapeutic decision. CONCLUSION: Only a few years after its introduction, laparoscopic cholecystectomy has asserted itself as the predominant treatment option. But as far as acceptance and preference by the patient are concerned extracorporeal shockwave lithotripsy--as a non-invasive treatment modality--also enjoys high popularity and can be recommended as an alternative to surgery in suitable patients chosen according to the currently established stringent selection criteria.  相似文献   

14.
Efficiency of organisation of management of the injured and diseased in combat operations in 1991/2 and results of hospital treatment are studied. The questionnaire was established for collection of data about stationary treatment of the wounded and diseased in 7 military and 15 civilian medical institutions. Data about 9.243 injured of whom only 5.57% were civilians are especially analysed. In most cases injuries were inflicted by mine-explosive devices (48.77% in combat and 6.27% in non-combat operations), then those inflicted by bullets (38.58% in combat and 8.02% in non-combat operations). Self-inflicted injuries occurred in 5.79% in combat and 10.32% in non-combat operations. Injuries inflicted in non-combat operations were found in a high percentage (46.60). They mostly occurred in the open air (41.26%). Injuries of extremities are predominant (64.70%), then injuries of the head and neck (17.90%), thorax (9.90%), abdomen and pelvis (7.50%). Young men (20-24 years old) were commonly injured but the older ones (over 40 years) have been also frequently injured (18.30%). Evacuation of the wounded and diseased was performed mainly by ambulances (about 60%) or helicopters (16%), especially to the medical institutions far in the country (to M.M.A. up to 60%). The first aid was given within the first ten minutes after injury in 55.00% and within 30 minutes in 65.58% of cases. Mutual aid was most frequently applied (33.12%) and then first aid given by general practitioners (32.12%). Surgical treatment was provided one hour after injury to every fourth wounded (24.08%) and after six hours to more than one third of the wounded (31.88%).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

15.
The Rorschach protocols of 62 eating-disordered women were analyzed for content expressing symbiotic, separation, and counter-symbiotic strivings. Subjects were grouped into three symptom pattern groups and into borderline and nonborderline groups as measured by Gunderson's Diagnostic Interview for Borderlines (DIB). Very few differences in this content were found among the three symptom-based groups. Consistent and significant differences were found among these groups in the relation between overall Rorschach response productivity and the production of responses with this content. This suggests that the symptom patterns may reflect differing modes of self-regulation. Consistent and significant differences in the production of this content were also found between borderline and nonborderline groups, supporting clinically based claims that symbiotic Rorschach responses are diagnostic of borderline functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

16.
OBJECTIVE: To investigate side effects of methylphenidate and desipramine alone and in combination in hospitalized children with symptoms of attention-deficit hyperactivity disorder and depression. METHOD: A double-blind placebo controlled crossover design was used to investigate each medication alone and in combination. Side effect ratings and EKGs were done weekly. Pulse and blood pressure were monitored daily. RESULTS: Nausea, dry mouth, and tremor were present in at least twice as many children on combined methylphenidate and desipramine compared with any other condition. Nausea/vomiting, headaches, other aches, refusal of food, and feeling "tired" were significantly more frequent during the combined methylphenidate plus desipramine condition when compared with either methylphenidate alone or with baseline. Significantly higher ventricular heart rate was found on combined methylphenidate plus desipramine compared with desipramine alone, methylphenidate alone, and baseline. Prolonged PR interval and significantly higher heart rate occurred during desipramine alone compared with baseline. CONCLUSIONS: During the several-month duration of the study, there were more frequent side effects during combined methylphenidate plus desipramine treatment than with either medication alone. Clinically, side effects present during combined medication appeared to be similar to and no more serious than those associated with desipramine alone.  相似文献   

17.
For comparison with previous data on iron-carbon alloys, steady-state electrotransport experiments were performed on three alloys: Nickel-0.15 wt pct carbon, nickel-20 copper-0.13 carbon, and iron-7.2 copper-0.10 carbon. The current density was 2.20 to 2.85 × 107 AJm2 and the temperature was 1300 K (and also 1200 K for the nickel-carbon alloy). The Z* values obtained were +5.7, +5.7, and +4.5 respectively, for the three alloys. Present theory appears to be unable to explain the relation of these data to similar data on iron-carbon alloys. Formerly Postdoctoral Fellow, Department of Metallurgical and Materials Engineering, University of Florida, Gainesville, Florida  相似文献   

18.
For comparison with previous data on iron-carbon alloys, steady-state electrotransport experiments were performed on three alloys: Nickel-0.15 wt pct carbon, nickel-20 copper-0.13 carbon, and iron-7.2 copper-0.10 carbon. The current density was 2.20 to 2.85 × 107 AJm2 and the temperature was 1300 K (and also 1200 K for the nickel-carbon alloy). The Z* values obtained were +5.7, +5.7, and +4.5 respectively, for the three alloys. Present theory appears to be unable to explain the relation of these data to similar data on iron-carbon alloys.  相似文献   

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20.
The efficacies of meropenem (MPM) and cloxacillin (CLC) against two Staphylococcus aureus strains were established in vitro. A pharmacodynamic model equation, based on the concept that the killing rate depends on concentration and time, was fitted to the numbers of CFU. The parameters of the equation are maximum killing rate, time point of maximum killing, and 50% effective concentration (EC50). The EC50s for the two strains were 0.047 and 0.040 mg/liter, respectively, for MPM and 0.105 and 0.121 mg/liter, respectively, for CLC. Calculated values of the parameters were used to predict the numbers of CFU at exponentially decreasing concentrations in vitro as well as in an experimental infection model. The prediction for in vitro conditions gave a satisfactory fit (R2, between 0.862 and 0.894). In vivo the numbers were predicted with the assumption that killing rate in vivo is proportional to that in vitro (R2, between 0.731 and 0.973). The proportionality factor ranged between 0.23 and 0.42; this variation was due mainly to covariation with growth rates in control animals, without other significant differences between antibiotics or strains.  相似文献   

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