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PubMed1999

Evidence that the Igkappa gene MAR regulates the probability of premature V-J joining and somatic hypermutation.

The Igkappa gene contains an evolutionarily conserved nuclear matrix association region (MAR) adjacent to the intronic enhancer. To test for the function of this MAR, we created mouse lines with a targeted MAR deletion. In MAR knockout animals, the immune system was normal in nearly all respects, including the distributions of various B cell populations and Ab levels. However, in pro-B cells, enhanced rearrangement was noted on the MAR- allele in heterozygotes. In addition, the efficiencies for targeting and generating somatic mutations were reduced on MAR-deleted alleles. These results provide evidence for the MAR negatively regulating the probability of premature rearrangement and positively regulating the probability of somatic hypermutation.

Alleles↗

PubMed1999

Estimation of prostate cancer probability by logistic regression: free and total prostate-specific antigen, digital rectal examination, and heredity are significant variables.

BACKGROUND: Despite low specificity, serum prostate-specific antigen (PSA) is widely used in screening for prostate cancer. Specificity can be improved by measuring free and total PSA and by combining these results with clinical findings. Methods such as neural networks and logistic regression are alternatives to multistep algorithms for clinical use of the combined findings. METHODS: We compared multilayer perceptron (MLP) and logistic regression (LR) analysis for predicting prostate cancer in a screening population of 974 men, ages 55-66 years. The study sample comprised men with PSA values >3 microg/L. Explanatory variables considered were age, free and total PSA and their ratio, digital rectal examination (DRE), transrectal ultrasonography, and a family history of prostate cancer. RESULTS: When at least 90% sensitivity in the training sets was required, the mean sensitivity and specificity obtained were 87% and 41% with LR and 85% and 26% with MLP, respectively. The cancer specificity of an LR model comprising the proportion of free to total PSA, DRE, and heredity as explanatory variables was significantly better than that of total PSA and the proportion of free to total PSA (P <0.01, McNemar test). The proportion of free to total PSA, DRE, and heredity were used to prepare cancer probability curves. CONCLUSION: The probability calculated by logistic regression provides better diagnostic accuracy for prostate cancer than the presently used multistep algorithms for estimation of the need to perform biopsy.

Blood Proteins↗

PubMed2000

Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer.

We have previously demonstrated that a clinical model can be safely used in a management strategy in patients with suspected pulmonary embolism (PE). We sought to simplify the clinical model and determine a scoring system, that when combined with D-dimer results, would safely exclude PE without the need for other tests, in a large proportion of patients. We used a randomly selected sample of 80% of the patients that participated in a prospective cohort study of patients with suspected PE to perform a logistic regression analysis on 40 clinical variables to create a simple clinical prediction rule. Cut points on the new rule were determined to create two scoring systems. In the first scoring system patients were classified as having low, moderate and high probability of PE with the proportions being similar to those determined in our original study. The second system was designed to create two categories, PE likely and unlikely. The goal in the latter was that PE unlikely patients with a negative D-dimer result would have PE in less than 2% of cases. The proportion of patients with PE in each category was determined overall and according to a positive or negative SimpliRED D-dimer result. After these determinations we applied the models to the remaining 20% of patients as a validation of the results. The following seven variables and assigned scores (in brackets) were included in the clinical prediction rule: Clinical symptoms of DVT (3.0), no alternative diagnosis (3.0), heart rate >100 (1.5), immobilization or surgery in the previous four weeks (1.5), previous DVT/PE (1.5), hemoptysis (1.0) and malignancy (1.0). Patients were considered low probability if the score was <2.0, moderate of the score was 2.0 to 6.0 and high if the score was over 6.0. Pulmonary embolism unlikely was assigned to patients with scores < or =4.0 and PE likely if the score was >4.0. 7.8% of patients with scores of less than or equal to 4 had PE but if the D-dimer was negative in these patients the rate of PE was only 2.2% (95% CI = 1.0% to 4.0%) in the derivation set and 1.7% in the validation set. Importantly this combination occurred in 46% of our study patients. A score of <2.0 and a negative D-dimer results in a PE rate of 1.5% (95% CI = 0.4% to 3.7%) in the derivation set and 2.7% (95% CI = 0.3% to 9.0%) in the validation set and only occurred in 29% of patients. The combination of a score < or =4.0 by our simple clinical prediction rule and a negative SimpliRED D-Dimer result may safely exclude PE in a large proportion of patients with suspected PE.

Algorithms↗

PubMed2000

A probability model of vector behavior: effects of DDT repellency, irritancy, and toxicity in malaria control.

A probability model of how DDT residues may function within a malaria control program is described. A step-wise organization of endophagic behaviors culminates in a vector acquiring a human blood meal inside the house. Different vector behaviors are described, epidemiologically defined, temporally sequenced, and quantified with field data. Components of vector behavior and the repellent, irritant, and toxic actions of insecticide residues are then assembled into a probability model. The sequence of host-seeking behaviors is used to partition the total impact of sprayed walls according to the three chemical actions. Quantitatively, the combined effect of repellency and irritancy exert the dominant actions of DDT residues in reducing man-vector contact inside of houses. These relationships are demonstrated with published and unpublished data for two separate populations of Anopheles darlingi, for Anopheles gambiae and Anopheles funestus in Tanzania, and Anopheles punctulatus in New Guinea.

Animals↗

PubMed1975

[Theoretically probable assessment of the effectiveness of individualized combined antibiotic therapy of patients with suppurative inflammatory processes].

Efficiency of individual combined antibiotic therapy of patients was estimated in comparison to the use of single antibiotics of their fixed combinations without any special control group. Since the essence of the study was practically in successive appliance of the 2 methods of therapy to the same group of the patients, it was possible to carry out theoretically probable estimation of the final result as a summation effect of both methods and to define the probable result of the 2 nd method. The study of the results of the treatment of the patients with purulent-inflammatory processes showed significant advantages of the individual combined antibiotic therapy.

Animals↗

PubMed2000

Heterozygosity probabilities for normal relatives of isolated cases affected by incompletely penetrant conditions and the calculation of recurrence risks for their offspring. I. Autosomal dominant genes.

Heterozygosity probabilities P(het) for relatives of isolated cases produced by incompletely penetrant autosomal dominant genes and recurrence risks for their offspring, R = P(het).K/2, where K is the penetrance value, have been calculated in the literature for some simple particular situations. Bayes theorem and elements from the theory of finite difference equations enabled us to derive the heterozygosity probability for any individual belonging to a pedigree containing an isolated case affected with an incompletely penetrant autosomal dominant disorder. The generalized formula here derived is valid for most particular cases thus far studied in the literature.

Family Health↗

PubMed1975

Probability learning in retarded children with differing histories of success and failure in shcool.

The effects of school-induced success and failure experiences on the probability-learning performances of retarded children were investigated. In previous laboratory research, the hypotheses has been suggested that failure experiences would lead to greater maximization, less patterning, and less shifting of responses than success experiences. Fifteen retarded children exposed to repeated failure in the classroom, 15 retarded children exposed to a relatively high level of success in special-education classes, and 15 nonretarded children served as subjects. All subjects were matched for MA. The hypothesis suggesting that the laboratory findings generalized to the classroom was confirmed. In addition, it was found that locus of control and need for achievement were significant correlates of probability-learning performance. However, only locus of control differentiated the subject groups.

Achievement↗

PubMed2000

Probability to retrieve testicular spermatozoa in azoospermic patients.

AIM: The degree of probability to retrieve spermatozoa from testicular tissue for intracytoplasmic sperm injection into oocytes is of interest for counselling of infertility patients. We investigated the relation of sperm retrieval to clinical data and histological pattern in testicular biopsies from azoospermic patients. METHODS: In 264 testicular biopsies from 142 azoospermic patients, the testicular tissue was shredded to separate the spermatozoa, histological semi-thin sections of which were then evaluated using Johnsen score. RESULTS: The retrieval of spermatozoa correlated significantly ( P < 0.001) with the testicular volume ( r = 0.49), the FSH concentration ( r = -0.66), the maximum score (r = 0.85) and the mean Johnsen score (r = 0.81). In the multivariate regression analysis the successful testicular sperm extraction showed the closest relationship to the maximum score. The testicular volume correlated significantly with the mean Johnsen score ( r = 0. 64, P < 0. 001), and the basal serum FSH concentration mainly with the maximum score ( r = - 0.77; P < 0.001). Patients with a history cryptorchidism showed a significantly lower Johnsen score compared to the patients who did not have any testicular disease in the past (3.7 +/- 2.4 vs. 5.9 +/- 2.5; P < 0. 01). CONCLUSION: In a limited range, the testicular volume and the FSH concentration in serum were related to the Johnsen score which correlated significantly with the sperm retrieval. The successful sperm retrieval can be expected in all azoospermic patients irrespective of the results of clinical examination. However, the probability of retrieval of spermatozoa decreased significantly in patients with a FSH level > 18 U/L, testicular volume < 5 mL, mean Johnsen score <5, and maximum Johnsen score <7.

Adult↗

PubMed2001

Coherent probability from incoherent judgment.

People often have knowledge about the chances of events but are unable to express their knowledge in the form of coherent probabilities. This study proposed to correct incoherent judgment via an optimization procedure that seeks the (coherent) probability distribution nearest to a judge's estimates of chance. This method was applied to the chances of simple and complex meteorological events, as estimated by college undergraduates. No judge responded coherently, but the optimization method found close (coherent) approximations to their estimates. Moreover, the approximations were reliably more accurate than the original estimates, as measured by the quadratic scoring rule. Methods for correcting incoherence facilitate the analysis of expected utility and allow human judgment to be more easily exploited in the construction of expert systems.

Adult↗

PubMed1993

[The calculation of probabilities as a basis for certainty in medicine].

Medicine underwent a serious crisis in the changeover from the 18th to the 19th century. Resorting to the calculation or probabilities as a means to providing Medicine with the desired precision and certainty was one of the most notable features of the remedies taken by doctors to emerge from this crisis. This resorting to the calculation of probabilities was very controversial and hotly debated at that time and we hope to show that this was indeed the case in France.

France↗

PubMed2002

Estimating the probability of bird mortality from pesticide sprays on the basis of the field study record.

The outcome of avian field studies was examined to model the likelihood of mortality. The data were divided into clusters reflecting the type of pesticide application and bird guilds present on site. Logistic regression was used to model the probability of a bird kill. Four independent variables were tested for their explanatory power: a variable reflecting acute oral toxicity and application rate; a variable reflecting the relative oral to dermal toxicity of the pesticides; Henry's law constant; and a variable reflecting possible avoidance of contaminated food items, the hazard factor (HF). All variables except for HF significantly improved model prediction. The relative dermal to oral toxicity, especially, was shown to have a major influence on field outcome and clearly must be incorporated into future avian risk assessments. The probability of avian mortality could be calculated from a number of current pesticide applications and the conclusion was made that avian mortality occurs regularly and frequently in agricultural fields.

Animals↗

PubMed1986

[The net probability of occurrence of demographic events and type of distribution].

"In this paper two methods of calculation of the net probability were analysed thoroughly--[the] Schwartz-Lazar method and [the] Chiang method--in consideration of [the inherent assumptions] in these methods...in reference to examined distributions, and [the] effect of these assumptions on calculated net probability...." (SUMMARY IN ENG AND RUS)

Demography↗

PubMedDate not supplied

Major hepatic resection reduces the probability of intrahepatic recurrences following resection of colorectal carcinoma liver metastases.

BACKGROUND/AIMS: The use of major versus limited hepatic resection for colorectal carcinoma liver metastases remains controversial. We evaluated the role of major hepatic resection in managing patients with colorectal carcinoma liver metastases. METHODOLOGY: We performed a retrospective analysis of 102 patients undergoing either major (n = 61) or limited (n = 41) hepatic resection for colorectal carcinoma metastases. Major hepatic resection was defined as segmentectomy or more extensive hepatic resection; limited hepatic resection was defined as non-anatomic removal of the liver tumor plus a rim of normal parenchyma. The median follow-up period was 94 months. RESULTS: Patients undergoing major hepatic resection had larger hepatic tumors than those undergoing limited hepatic resection (p < 0.001, Fisher's exact test). The cumulative probability of intrahepatic recurrences after major hepatic resection was significantly lower than that after limited hepatic resection (p = 0.010, log-rank test). Major hepatic resection independently reduced the probability of intrahepatic recurrences (p = 0.043, Cox's proportional hazards model). Limited hepatic resection frequently resulted in recurrences within the same segment or the same lobe of the remnant liver. CONCLUSIONS: Major hepatic resection is more effective in reducing the risk of intrahepatic recurrences than limited hepatic resection in patients with resectable colorectal carcinoma liver metastases.

Adenocarcinoma↗

PubMed1992

Exclusion probabilities of red cell antigen systems for Chinese.

Little data are available in the literature for Chinese people, regarding genotype frequencies of red cell antigen systems. Furthermore, no recommendations for proper selection of red cell antigen systems for paternity testing have been established for a Chinese population. Consequently, calculating a paternity index is impossible. Blood typing of 336-1919 samples of Taiwanese Chinese was undertaken to determine various red blood cell antigens. Gene frequencies and probabilities of exclusion (PE) for the red cell antigen systems were then analyzed. The distributions of the red cell antigens were quite homogeneous. The incidence of D, s, k, Fya and Lub antigens was high, 99.6%, 99.7%, 100%, 99.8% and 99.4%, respectively. On the contrary, that for the K antigen was very low. The PE for the ABO, Rh, MNSs, Kell, Duffy, Kidd, P, and Lutheran systems was 0.1910, 0.1961, 0.2237, 0.0003, 0.0444, 0.1870, 0.0806, and 0, respectively. The cumulative PE (CPE) using ABO, Rh, MNSs, Kell, Duffy, Kidd, P and Lutheran systems was 0.6394, while CPE for ABO, Rh, MNSs, Duffy, Kidd, and P systems was 0.6394. Thus, it appears that the Kell and Lutheran systems are not suitable for paternity testing because of their low probability of exclusions. Duffy system may also be excluded for its low PE. The CPE for ABO, Rh, MNSs, Kidd and P systems was 0.6226.

Asian People↗

PubMedDate not supplied

Probabilities of developing cancer over the life span of a Japanese--update.

In a previous study, we investigated the probability of developing cancer in the entire life span of a Japanese using population-based cancer incidence data from 1994, to obtain a relevant index of the impact of cancer occurrence on the Japanese population (APJCP, 1: 333-336, 2000). In the present paper, we have updated the information using the latest reports on cancer incidence in Japan in 1998. A method based on the cumulative risk of cancer was employed to estimate the probability of developing cancer up to 84 years of age, the average life expectancy of a Japanese female, and 79 years of age, the average life expectancy of a Japanese male. The time trend was also analyzed from 1975-1998. The cumulative risk of developing cancer in any site up to 84 and 79 years of age was 45% and 36% for males, 27% and 21% for females, and 35% and 28% for both genders, respectively. The cumulative risk showed an increasing time trend before leveling-off after 1985. From our results, it is expected that nearly one-third of Japanese males and one-fourth of Japanese females will develop cancer by the time they reach the average life expectancy.

Adult↗

PubMed2003

[Quantification of the probability of milk contamination by Listeria monocytogenes during manufacture of hard cheese].

BACKGROUND: The present work is concerned with the probability of contamination by Listeria monocytogenes in the artisanal manufacture of Swiss Emmental hard cheese made from raw milk. The simulation model follows the evolution of the contaminant flora from raw milk at the farm to milk mixing, storage at the cheese factory and to the cheese manufacturing process. METHODS: The simulations are based on models of predictive microbiology, namely the exponential growth model of bacteria including the lag-time, a cardinal growth model and a Log-linear model of thermal deactivation of bacteria. RESULTS: The results of the actual simulation indicate that the contamination of milk at the farm is a rare event (P=0.0036), but the mixing of milk at the cheese factory leads to a higher probability of contamination of cheese milk (P=0.07). Elevated bacterial concentrations are mainly due to cases of mastitis involving Listeria monocytogenes. The decline in bacterial counts during cheese manufacture depends on the curing temperature (52-54 degrees C) and varies between 1.5 and 3.2 Log cfu/ml. Freshly manufactured Emmental-cheese made from contaminated raw milk is expected to have only 4.6 cfu of heat injured Listeria monocytogenes /kg cheese mass in the press. CONCLUSION: Depending on listeria evolution, from the press to the product consumption, consumer exposure has been evaluated and might result in 1 to 10 Listeria monocytogenes per portion of cheese. The bacterial presence could be due to recontamination during packaging, distribution and cheese preparation by the consumer. Based on the presented data and estimations, it is concluded that the consumption of traditionally/artisanal manufactured Swiss Emmental hard cheese presents an extremely low, but existent risk, especially for people with a deficient or diminished immune system.

Animals↗

PubMed2004

[Self-rated health and probability of death among middle-aged Kaunas population (20-year follow-up)].

The aim of this study was to examine the self-rated health differences in relation with risk factors among middle-aged men and women and to assess the probability of death from all causes, from cardiovascular diseases and from ischemic heart disease in the self-rated health groups during the 20-year follow-up. In the framework of the World Health Organization MONICA-1 survey (1983-1984) random samples of Kaunas men and women aged 35-64 and stratified by age and gender (response rate 70.2%) were examined using standard epidemiological methods. Self-rated health was divided into five levels based on information from questionnaire: excellent, very good, good, fair, or ill. The participants of the survey were followed-up in terms of the end points reached, from the beginning of each study until December 31, 2001. The study population was followed-up through the death register: among women there were 197 deaths (94 deaths from cardiovascular diseases and 44 deaths from ischemic heart disease) and among men there were 303 deaths (154 deaths from cardiovascular diseases and 98 from ischemic heart disease). Among dead men and women the prevalence of fair and ill self-rated health was higher as compared to alive ones (respectively, 71.0% and 54.9%, p<0.001; 84.3% and 76.7%, p<0.05). Among dead women with hypercholesterolemia (> or =5.0 mmol/l), overweight (body mass index > or =25.0 kg/m2), nonsmoking and sufficient physical activity the prevalence of "fair and ill" self-rated health was higher as compared to alive; the prevalence of "fair and ill" self-rated health in men with hypercholesterolemia (> or =5.0 mmol/l) and sufficient physical activity was higher among dead as compared to alive. During the 20 year follow-up the probability of death from all causes, cardiovascular and ischemic heart disease among men with self-rated health as "ill and fair" as compared to "excellent and very good", showed statistically significant difference (log rank=18.5, p<0.001, log rank=10.8 p<0.01, log rank=8.9, p<0.01, respectively); among women there were no significant differences. The results of this study suggest that special attention and care should be directed to persons with reporting self-rated health as "fair and ill".

Adult↗

PubMed2005

The probability of blindness in patients treated for glaucoma.

BACKGROUND: To investigate the risk factors and probability of blindness in patients treated for glaucoma. METHODS: The study design was a retrospective, hospital-based, clinical chart, review study. Medical records were reviewed from patients seen between January 2003 and December 2003 at the Kaohsiung Chang Gung Memorial Hospital eye clinic, who had been diagnosed with glaucoma in 1986 or later and who had been treated for at least 2 years for glaucoma. RESULTS: A total of 186 charts were reviewed, which included 66 patients who were blind in at least one eye from glaucoma on presentation. A total of 172 patients and 290 eyes were followed-up for a mean duration of 10.6 +/- 4.67 years. Twenty seven patients and 31 eyes developed blindness from glaucoma during follow-up. The Kaplan-Meier survival estimate at 16 years was 28.6% for glaucoma-related blindness in at least one eye. A worse visual field on presentation, older age, and poor compliance during therapy were significantly associated with the development of blindness. Glaucoma type, a gender difference, systemic disease, greater intraocular pressure fluctuation in the last year of therapy and blindness in one eye on presentation did not show a significant relationship with the rate of development of blindness. CONCLUSION: Blindness from treated glaucoma is considerable. Our results gave a 28.6% probability of blindness at 16 years in at least one eye. An older age, poor compliance and a worse visual field on presentation were significant risk factors.

Adult↗