Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Probability Theory”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,063 records · Page 59Linked to original sources
PubMed2002

An evaluation of the effectiveness of extended lymph node dissection in patients with gastric cancer: a retrospective study of 1403 cases at a single institution.

BACKGROUND: Many investigators have reported that extended lymph node dissection (D2 dissection) is probably an effective procedure. However, the theory that D2 dissection leads to an improvement in survival has not been confirmed in randomized trials. We attempted to confirm the effectiveness of D2 dissection with gastrectomy for gastric cancer. MATERIALS AND METHODS: Gastric cancer patients (1403) underwent curative resection by D1 (991 patients) or D2 (412 patients) dissection with gastrectomy. Survival rates calculated for all patients and subdivided for stage, depth of invasion, and lymph node metastasis were compared between the two groups. The diagnosis of lymph node metastasis was compared between macroscopic and histological findings. RESULTS: There was no significant difference in the survival of patients overall. However, in the patients with stage II, T1 or T2, or N1 disease, the survival of the D2 group was significantly better than that of the D1 group. The false positive rates of lymph node metastasis were 53.3% in the N1 group, 26.2% in the N2 group, and 9.2% in the N3 group. In a considerable proportion of the N1 and N2 patients, histological findings proved more or fewer metastases than macroscopic diagnosis. CONCLUSIONS: Metastatic lymph nodes should be resected as far as possible. D2 dissection with gastrectomy is recommended for T1, N1 or T2, N1 disease, particularly in younger patients.

False Positive Reactions↗
PubMed1985

Platelet sensitivity in vitro to adenosine-5'-diphosphate and prostacyclin and diabetic retinopathy.

Platelet sensitivity to adenosine diphosphate and prostacyclin in diabetes has been assessed using collision theory and the concept of 'sticking probability' (the probability of particle union). Twenty Type 1 (insulin-dependent) diabetic men (10 with no or minimal retinopathy and a matched group of 10 with proliferative retinopathy) and 10 age-matched nondiabetic men were studied. Platelets from the 20 diabetic patients required, on average, 37% less adenosine diphosphate to achieve a sticking probability of 0.5 (ED50) compared with platelets from the non-diabetic subjects (medians 1.50 and 0.95 mumol/l, respectively; p less than 0.01). The platelet prostacyclin response was assessed by the dissociation constant (Ki) for inhibition of adenosine diphosphate-induced aggregation. Platelets from the diabetic patients had similar prostacyclin sensitivity to those from the non-diabetic subjects (medians 0.42 and 0.42 respectively). Diabetic patients with and without retinopathy had similar platelet sensitivity to both adenosine diphosphate and prostacyclin.

Adenosine Diphosphate↗
PubMed1987

Limit theorems for the population size of a birth and death process allowing catastrophes.

The linear birth and death process with catastrophes is formulated as a right continuous random walk on the non-negative integers which evolves in continuous time with an instantaneous jump rate proportional to the current value of the process. It is shown that distributions of the population size can be represented in terms of those of a certain Markov branching process. The ergodic theory of Markov branching process transition probabilities is then used to develop a fairly complete understanding of the behaviour of the population size of the birth-death-catastrophe process.

Animals↗
PubMedDate not supplied

Noncompartmental models of whole-body clearance of tracers: a review.

Noncompartmental models are defined as models that allow for transport of material through regions of the body that are not necessarily well-mixed or of uniform concentration. The clearance of a substance of interest (metabolite or drug) from a noncompartmental system will not necessarily be governed by a sum of exponentials or even be describable by a set of ordinary differential equations. The model may involve diffusion or other random walk processes, leading to the solution in terms of the partial differential equation of diffusion or in terms of probability distributions. It may use the theory of linear systems to obviate the need for defining any precise anatomical structure. A number of the models reviewed deal with plasma clearance curves that are best described by power functions of time. Circulatory models are reviewed from their inception to the present. Recent studies on clearance as a fractal process are introduced.

Animals↗