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1.
A methyl methacrylate casting technique was used to make detailed casts of the intracerebral venous system of four human cadaver specimens. Seven of the eight petrous apices studied were diploeic (n = 5), or pneumatic (n = 2) and had venules coursing in the anterior petrous apex. These venules form conduits connecting the cavernous to the inferior petrosal sinus or the jugular bulb and have not been previously described. In addition to the air cell system of the petrous apex, these venules may represent pathways for the spread of infection and the development of petrous apicitis, Gradenigo's syndrome, and the rare otogenic cavernous sinus thrombophlebitis. Their presence also may help explain the location of cholesterol granulomas, which afflict this area of the skull base.  相似文献   

2.
Factors associated with preweaning mortality in lambs were identified by developing risk profiles with logistic regressions for perinatal and postnatal mortality. Compared with heavy lambs, lambs of low birth weight had almost twice the risk of perinatal mortality (odds ratio [OR] = 1.9) and lambs of average weight had a slightly lower risk (OR = 0.7). Two of four lambing location categories affected perinatal mortality, with lambs born at unmonitored areas at greatest risk (OR = 2.7). Multiple births increased the risk of perinatal mortality (OR = 1.5), especially among Targhee lambs (OR = 4.0). Breed variations in perinatal mortality were significant in Suffolk lambs (OR = 1.9) and Booroola Rambouillet lambs (OR = 2.1). Lambs born weak had an increased risk of postnatal mortality while strong lambs had a decreased risk (OR = 3.7 and 0.6, respectively) if the dam had an adequate milk supply. Poor milk supply increased the risk of postnatal mortality for lambs of average vigour (OR = 3.3), but did not change the risk for weak or strong lambs. Male lambs castrated at 30 days of age were at less risk of postnatal mortality (OR = 0.3) than females. There were slight increases in the risk of postnatal mortality for intact males (OR = 1.3), low birth weight lambs (OR = 1.6), and lambs born in sheds (OR = 1.3). Suffolk lambs (OR = 1.8) and Targhee lambs (OR = 1.6) had a higher risk of postweaning mortality.  相似文献   

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4.
Abnormal interaction between low density lipoprotein receptors (LDLR) and their ligands, apolipoprotein E and B, causes decreased catabolism of lipoproteins which carry these apolipoproteins (VLDL, IDL and/or LDL) and thereby increased plasma concentrations of these. In familial hypercholesterolemia (FH), abnormal interaction is due to mutations in the LDLR gene, and in type III hyperlipidemia due to mutations in the apo E gene. A few mutations in the apolipoprotein B (apo B) gene have been described, of which the apo B-3,500Arg-Gln seems by far the most frequent, that causes defective binding to normal LDLR. The metabolic disorder associated with these mutations has been named familial defective apolipoprotein B-100 (FDB). The frequency of the apo B-3,500Arg-Gln mutation is particularly high in Central Europe (Switzerland) with lower frequencies south of the Alpes, in Russia and in Scandinavia. We found an incidence of 1/1250 of the mutation in Denmark (III), employing a DNA based assay optimized to allow detection of the mutation in very small amounts of DNA (I). Since other mutations in the receptor binding domain of the apo B-100 have been described, we developed another DNA based assay, employing DGGE technique, to screen for other mutations in the region of amino acid 3,456 to 3,553 (II). However, no other mutations but the apo B-3,500Arg-Gln have so far been detected in Danish hypercholesterolemic patients. In a study of 5 Danish families with FDB (46 heterozygous FDB patients and 57 unaffected relatives) we found that FDB patients had significantly increased mean cholesterol and LDL cholesterol concentrations, but with a wide range of variation and with approximately 30% having cholesterol concentrations below the 95th percentile for the general population (IV). This was confirmed in a compilation of data on 205 FDB patients from the Netherlands, Germany and Denmark (V). In this study we also compared the biochemical and clinical features of FDB with those of 101 Danish FH patients in whome FDB had been ruled out. Our data support, that the LDL cholesterol elevation is less pronounced in FDB than in FH and that the age-specific prevalence of atherosclerotic cardiovascular disease (CVD) is lower in FDB than in FH. In the compiled study of 205 FDB heterozygotes (V), we found that age, gender and genetic variation in the LDLR gene explained a considerable part of the between-individual variation in total and LDL cholesterol. We conducted a prospective study of the lipid lowering effect of pravastatin and gemfibrozil in 30 Danish FDB patients (VI). Together with other, retrospective, studies, we conclude that the cholesterol lowering effect of HMG-coA-reductase inhibitors, anion binding resins and nicotinic acid is fully comparable to that observed when treating FH patients and type IIa hypercholesterolemic patients, without clinical signs of FH.  相似文献   

5.
Aspirin (O-acetylsalicylic acid) has been used to synthesize prodrugs of 3'-azido-3'-deoxythymidine (AZT) and 3'-deoxy-3'-fluorothymidine (FLT). The mixed anhydride between aspirin and trifluoroacetic acid was synthesized and reacted with AZT and FLT to give the blocked nucleosides attached through the 5'-O position to the 2-position of 2-methyl-4H-1,3-benzodioxin-4-one. The prodrugs showed the same activities against HIV-1 in MT-4 cells as the original drugs. Hydrolysis of the synthesized prodrugs in the growth medium, used for anti-HIV investigations, resulted in formation of 5-O acetylated drugs which were subsequently hydrolyzed into the original drugs.  相似文献   

6.
Association of personal health practices with mortality from all causes was studied. In 1988, 4,318 residents aged 40 years and over in a rural town of Miyagi Prefecture, north-eastern part of Japan, completed a self-administered questionnaire including items on smoking, alcohol consumption, physical activity, sleeping patterns, and weight status. During the four year follow-up, 207 subjects had died. Relative risks (95 percent confidence intervals) of death from all causes adjusted for age, sex, and other confounding variables were 0.62 (0.39-0.98) for never smoking, 0.51 (0.34-0.78) for no or moderate alcohol consumption, 0.66 (0.42-1.04) for exercising physical activity, 0.78 (0.56-1.10) for 7-8 hours of sleep, and 0.75 (0.52-1.07) for not being underweight. Compared with performing only 0-1 of the five low-risk practices concerning the items mentioned above, relative risks (95 percent confidence intervals) of all-cause mortality for performing 3, or all 5 practices were, 0.49 (0.30-0.80) and 0.14 (0.03-0.61), respectively (trend p = 0.0001). The results remained unchanged even after excluding early death occurring within the first year of the follow-up, or excluding the subjects with past history of diseases. Further research is required to explore the combined effects of the practices on mortality for longer observational period.  相似文献   

7.
We wished to ascertain whether the measurement of maternal serum human chorionic gonadotropin (MShCG) in the serum of pregnant women with unexplained elevations of maternal serum alpha-fetoprotein (MSAFP) would more precisely define those women at risk of adverse pregnancy outcomes. MShCG was measured in samples of serum obtained from women in the second trimester of pregnancy who had elevated MSAFP, normal Level II ultrasounds, and normal fetal karyotypes. Based on the characteristics of a receiver-operator curve for MShCG and birth weight, patients were divided into two groups and pregnancy outcomes were compared. Pregnant women with an unexplained elevation in MSAFP, who also had an abnormal MShCG (< or = 0.5 MoM > or = 2.5) were at significantly greater risk of delivering a low-birth-weight infant compared to women with a normal MShCG (43% and 15%, respectively; P = 0.013). They were also more likely to deliver a preterm infant (48% and 11.9%), respectively; P = 0.001). In the prediction of low birth weight, an abnormal MShCG had a sensitivity of 50%, a specificity of 81%, and a positive predictive value of 43%; in the detection of preterm delivery the values were 59%, 88%, and 48%, respectively. These findings suggest that in pregnant women with a second trimester unexplained elevation in MSAFP, abnormal MShCG levels may identify a group of women at high risk of preterm delivery or delivery of a low-birth-weight infant.  相似文献   

8.
Oral liposome drug delivery has been the subject of much cynicism. Results have been quite variable and, for the most part, have not been predicated on specific objectives that would lead to success. Prerequisites are stability in the gastrointestinal environment and binding to specific sites. Transport via paracellular and transcellular routes from normal epithelial tissue or Peyer's patches leads to different outcomes of drug delivery and immunization, respectively. Polymerized, microencapsulated, and polymer-coated liposomes have all increased the potential of oral liposomes. Using targeted liposomes and a greater understanding of their cellular processing will ultimately lead to effective therapies from oral liposomes.  相似文献   

9.
PROBLEM: Mother-to-child transmission is a major route for the spread of human immunodeficiency virus (HIV) worldwide. Our understanding of its mechanisms and parameters is still limited. Among the factors possibly involved in virus passage determination are the level and quality of antiviral humoral response. METHOD OF STUDY: Anti-HIV-1/Lai neutralizing activity in sera from 35 mother-infant pairs (in which 13 transmission cases occurred) was investigated, as was the complement-mediated antibody-dependent enhancement capacity of the same sera. RESULTS: Neutralization titers of 640 or more were found only in four mothers of uninfected children, but this result was not significant. No significant link was obtained with the occurrence of complement-mediated, antibody-dependent enhancement. CONCLUSIONS: As suggested by a synthesis of the literature, vertical transmission of HIV is probably the result of multiple active and/or stochastic parameters in the mother, the fetal structures, and the viral population. The precise definition of cellular mechanisms involved in in utero infection would help to better define which immune activity in the mother should be more carefully considered.  相似文献   

10.
Genetic variation can influence the effects of hypocholesterolemic dietary interventions on lipoproteins involved in coronary artery disease (CAD). Individuals with the E4 allelic variant of the apo E gene exhibit greater low-density lipoprotein (LDL) cholesterol reductions on low-fat, low-cholesterol diets than subjects with other alleles. Another apolipoprotein structural variant, apo A-IV-2, attenuates the response of LDL cholesterol to dietary cholesterol. Other studies have associated lipoprotein response to dietary modifications with DNA polymorphisms in the genes for apo B and the LDL receptor, and in the promoter region of the apo A-I gene. Studies in our laboratory involving variation in dietary fat and carbohydrate intake have demonstrated that alleles at the apo E gene locus are associated with changes in large, buoyant but not smaller, denser LDL subclasses. On the other hand, a low-fat diet induces a reduction in small, dense LDL in individuals with a genetically influenced metabolic profile characterized by a predominance of these particles. Moreover, reductions in LDL cholesterol and apo B in these subjects are greater than in the majority of subjects with larger LDL. Since in humans a predominance of small LDL signifies a higher risk for coronary artery disease than that associated with larger LDL, metabolic and genetic factors contributing to the small LDL trait may account for a substantial portion of the coronary risk benefit attributed to reduced-fat diets. Studies in large population groups or in suitable animal models will be necessary to determine the impact of genetic influences on dietary response affecting lipoprotein metabolism and their interactions with other environmental and hormonal factors.  相似文献   

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12.
A high frequency of meningeal lesions was found at autopsy in foals dying perinatally. Such lesions are considered an index of injury to the fetal central nervous system, from trauma and/or hypoxia during birth. Their incidence in the sample examined (26 foals) is similar to that observed in the perinatal mortality of lambs and calves.  相似文献   

13.
An epidemiologic study of malignant tumors was carried out in a cohort of population of a district in Moscow. The district is situated on the leeward side of a cluster of factories which discharge 270 cu tons of pollutants per year. Nine of the eleven apartment houses under study were put up in the 60-70 ies when the factories were in operation. The cohort included 1,095 males and females who had lived in that district at least 5 years until the start of the investigation. The tumor morbidity and mortality in this cohort were evaluated for the period of 1988-1992. Morbidity of virtually all known tumors and mortality proved to be in excess of all expectations. However, significant differences between the actual and expected levels were obtained in the total number of tumors, in females, only (actual number-24; expected number-13.76), and for breast tumors (7 and 2.82, respectively).  相似文献   

14.
Subdividing the age group 65 and over into finer age groups unmasks race differentials in mortality and morbidity that often favor blacks in the older age groups. This article describes the unusual phenomena; proposes a systematic research program to explain them; and discusses existing data sets for their analysis.  相似文献   

15.
Priming and recollection are expressions of human memory mediated by different brain events. These brain events were monitored while people discriminated words from nonwords. Mean response latencies were shorter for words that appeared in an earlier study phase than for new words. This priming effect was reduced when the letters of words in study-phase presentations were presented individually in succession as opposed to together as complete words. Based on this outcome, visual word-form priming was linked to a brain potential recorded from the scalp over the occipital lobe about 450 ms after word onset. This potential differed from another potential previously associated with recollection, suggesting that distinct operations associated with these two types of memory can be monitored at the precise time that they occur in the human brain.  相似文献   

16.
The activity of N-acetyltransferase (NAT) and catalase was measured in the tissues of placenta, full venous blood and full umbilical cord blood in 141 complicated pregnancies. The control group consisted of 34 physiological pregnancies. The enzymes activity was marked by use of biochemical methods. It has been shown that NAT and catalase is the most active in the group of physiological pregnancies. The decrease of NAT and catalase in venous and umbilical cord blood is correlated with the decrease of the activity these enzymes in placenta.  相似文献   

17.
CONTEXT: Early risk stratification of patients with myocardial infarction is critical to determine optimum treatment strategies and enhance outcomes, but knowledge of the prognostic importance of the initial electrocardiogram (ECG) is limited. OBJECTIVE: To assess the independent value of the initial ECG for short-term risk stratification after acute myocardial infarction. DESIGN: Retrospective analysis of the Global Utilization of Streptokinase and t-PA (alteplase) for Occluded Coronary Arteries (GUSTO-I) clinical trial database. SETTING: A total of 1081 hospitals in 15 countries. PATIENTS: From the 41 021 patients enrolled in the overall study, we selected those who presented within 6 hours of chest pain onset with ST-segment elevation and no confounding factors (paced rhythms, ventricular rhythms, or left bundle-branch block) on the ECG performed before thrombolysis was administered (n=34 166). MAIN OUTCOME MEASURE: Ability of initial ECG to predict all-cause mortality at 30 days. RESULTS: Most ECG variables were associated with 30-day mortality in a univariable analysis. In a multivariable analysis combining the initial ECG variables and clinical predictors of mortality, the sum of the absolute ST-segment deviation (both ST elevation and ST depression: odds ratio [OR], 1.53; 95% confidence interval [CI], 1.38-1.69), ECG, heart rate (OR, 1.49; 95% CI, 1.41-1.59), QRS duration (for anterior infarct: OR, 1.55; 95% CI, 1.43-1.68), and ECG evidence of prior infarction (for new inferior infarct: OR, 2.47; 95% CI, 2.02-3.00) were the strongest ECG predictors of mortality. A nomogram based on the multivariable model produced excellent discrimination of 30-day mortality (C-index, 0.830). CONCLUSIONS: In patients presenting with myocardial infarction accompanied by ST-segment elevation, components of the initial ECG help predict 30-day mortality. This information should be valuable in early risk stratification, when the opportunity to reduce mortality is greatest, and may help in assessing outcomes adjusted for patient risk.  相似文献   

18.
PURPOSE: This study analyzed the findings in a large series of adenomatoid odontogenic tumors (AOT) in Nigerians. PATIENTS AND METHODS: Hospital records of all cases of AOT diagnosed at three teaching hospitals were reviewed and analyzed. RESULTS: Most of the tumors were intraosseous (central) (98.3%) and of the follicular type (75%). Females were more frequently affected than males (1.4:1), and patients in their second decade of life were most frequently affected (75%). Patients with follicular AOT were relatively younger (15.2 +/- 5.6 years) than those with extrafollicular tumors (20.9 +/- 13.8 years). However, males who presented with extrafollicular tumors (14.6 +/- 3.9 years) were relatively younger than their female counterparts (24.9 +/- 16 years). The maxilla was affected nearly twice as often as the mandible (1.8:1), and the canine tooth was frequently embedded in the tumor (76.9%). Although follicular tumors were most frequently located in the maxilla (76.3%), extrafollicular tumors were more commonly found in the mandible (69.2%). CONCLUSION: The distribution of this tumor in black Africans does not appear to be substantially different from that reported in caucasians.  相似文献   

19.
Asymptomatic gonorrhea: prevalence in a population of urban adolescents   总被引:1,自引:0,他引:1  
During a 12-month period, 2,672 sexually active youths, 12 to 16 years of age, had genital bacteriologic cultures for Neisseria gonorrhoeae. Anterior urethral cultures were obtained from 2,098 males of whom 2,064 had no symptoms or signs of genitourinary disease. Forty cultures (1.9%) were positive for gonorrhea. Of 574 females, 374 were asymptomatic and 26 (7.0%) had positive gonorrhea cultures from the cervix. Since adolescent boys are more likely to be sexual adventurers, the 1.9% carrier rate represents an important reservoir of gonorrhea and equal in importance to that found in the asymptomatic adolescent girl.  相似文献   

20.
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