Measurement of mRNA of 11 biomarkers by RT-PCR to detect lymph node involvement in cervical cancer

Lymph node metastases are a major prognostic factor in cervical carcinomas. The aim of this study was to characterize the expression of 11 markers in cervical tumors and negative lymph nodes and to determine which ones could be helpful for improving the specificity of molecular diagnosis of nodal involvement. Using TaqMan RT-PCR, we studied the expression of CK19, MUC1, HER1-HER4, VEGF, VEGF-C, uPA, MMP9, and PRAD1 in uterine cervical tumors and in histologically nonmetastatic lymph nodes of 8 patients diagnosed with locally advanced cervical cancer. We observed that CK19, MUC1, HER1-HER3, uPA, and VEGF had a significantly higher expression in cervical tumors than in the negative nodes, whereas VEGF-C expression level was higher in the negative nodes than in the tumors. PRAD1 harbored similar expression levels in the tumors and in the negative nodes. Interestingly, 1 of the 4 patients who presented a clinical recurrence, showed elevated HER1, HER2, uPA, and VEGF in the histologically negative nodes. Our results suggest that CK19, MUC1, HER1-3, uPA, and VEGF are biomarkers that have a higher expression in tumoral cervical tissues compared with the negative lymph nodes and could be useful to diagnose nodal involvement in uterine cervical carcinoma. Our results should encourage us in continue to investigate a greater number of patients, including patients with histologically involved nodes.     

Prognostic Factors of Melanoma Patients with Satellite or In-Transit Metastasis at the Time of Stage III Diagnosis

Background

Prognosis of patients with loco-regional skin metastases has not been analyzed in detail and the presence or absence of concurrent lymph node metastasis represents the only established prognostic factor thus far. Most studies were limited to patients already presenting with skin lesions at the time of initial diagnosis. We aimed to analyze the impact of a broad penal of prognostic factors in patients with skin metastases at the time of first metastatic spread, including patients with synchronous lesions already present at the time of initial diagnosis, stage I/II patients with loco-regional recurrence and patients initially presenting with skin metastasis but unknown primary melanoma.

Patients and Methods

We investigated disease-specific survival of 380 patients treated at our department between 1996 and 2010 using Kaplan Meier survival probabilities and Cox-proportional hazard analysis.

Results

Five-year survival probability was 60.1% for patients with skin metastases only and 36.3% for those with synchronous nodal metastases. The number of involved nodes and a tumor thickness of at least 3 mm had independent negative impact on prognosis. A strong relationship was identified between the risk of death and the number of involved nodes. Neither ulceration nor the timing of the first occurrence of metastases as either in stage I/II patients, at the time of excision of the primary melanoma or initially in patients with unknown primary tumor, had additional effects on survival.

Conclusion

Lymph node involvement was confirmed as the most important prognostic factor for melanoma patients with loco-regional skin metastasis including those with unknown primary tumor and stage I/II patients with skin recurrence. Consideration of the tumor thickness and of the number of involved lymph nodes instead of the exclusive differentiation into presence vs. absence of nodal disease may allow a more accurate prediction of prognosis for patients with satellite or in-transit metastases.     

Promotion time models with time-changing exposure and heterogeneity: application to infectious diseases

Promotion time models have been recently adapted to the context of infectious diseases to take into account discrete and multiple exposures. However, Poisson distribution of the number of pathogens transmitted at each exposure was a very strong assumption and did not allow for inter-individual heterogeneity. Bernoulli, the negative binomial, and the compound Poisson distributions were proposed as alternatives to Poisson distribution for the promotion time model with time-changing exposure. All were derived within the frailty model framework. All these distributions have a point mass at zero to take into account non-infected people. Bernoulli distribution, the two-component cure rate model, was extended to multiple exposures. Contrary to the negative binomial and the compound Poisson distributions, Bernoulli distribution did not enable to connect the number of pathogens transmitted to the delay between transmission and infection detection. Moreover, the two former distributions enable to account for inter-individual heterogeneity. The delay to surgical site infection was an example of single exposure. The probability of infection was very low; thus, estimation of the effect of selected risk factors on that probability obtained with Bernoulli and Poisson distributions were very close. The delay to nosocomial urinary tract infection was a multiple exposure example. The probabilities of pathogen transmission during catheter placement and catheter presence were estimated. Inter-individual heterogeneity was very high, and the fit was better with the compound Poisson and the negative binomial distributions. The proposed models proved to be also mechanistic. The negative binomial and the compound Poisson distributions were useful alternatives to account for inter-individual heterogeneity.     

Oviposition pattern of phytophagous insects: on the importance of host population heterogeneity

Frequency distributions of insect immatures per host are often fitted to contagious distributions, such as the negative binomial, to deduce oviposition pattern. However, different mechanisms can be involved for each theoretical distribution and additional biological information is needed to correctly interpret the fits. We chose the chestnut weevil Curculio elephas, a pest of the European chestnut Castanea sativa, as a model to illustrate the difficulties of inferring oviposition pattern from fits to theoretical distributions and from the variance/mean ratio. From field studies over 13–16 years, we show that 20 out of the 31 yearly distributions available fit a negative binomial and 25 a zero-inflated Poisson (ZIP). No distribution fits a Poisson distribution. The ZIP distribution assumes heterogeneity within the fruit population. There are two categories of host: the first comprises chestnuts unsuitable for weevil oviposition or in excess relative to the number of weevil females, and the second comprises suitable fruits in which oviposition behavior is random. Our results confirm this host heterogeneity. According to the ZIP distribution, the first category of hosts includes on average 74% of the chestnuts. A negative binomial distribution may be generated by either true or false contagion. We show that neither interference between weevil females, nor spatial variation in the infestation rate exist. Consequently, the observed distributions of immatures are not the result of false contagion. Nevertheless, we cannot totally exlude true contagion of immatures. In this paper we discuss the difficulty of testing true contagion in natural conditions. These results show that we cannot systematically conclude in favour of contagion when fitting a distribution such as the negative binomial or when a variance/mean ratio is higher than unity. Received: 22 September 1997 / Accepted: 15 December 1997     

Bacterial Density in Water Determined by Poisson or Negative Binomial Distributions

The question of how to characterize the bacterial density in a body of water when data are available as counts from a number of small-volume samples was examined for cases where either the Poisson or negative binomial probability distributions could be used to describe the bacteriological data. The suitability of the Poisson distribution when replicate analyses were performed under carefully controlled conditions and of the negative binomial distribution for samples collected from different locations and over time were illustrated by two examples. In cases where the negative binomial distribution was appropriate, a procedure was given for characterizing the variability by dividing the bacterial counts into homogeneous groups. The usefulness of this procedure was illustrated for the second example based on survey data for Lake Erie. A further illustration of the difference between results based on the Poisson and negative binomial distributions was given by calculating the probability of obtaining all samples sterile, assuming various bacterial densities and sample sizes.     

A frequency distribution for the number of hematogenous organ metastases

The number of metastases associated with a primary tumor can be a major determinant for the chance of cure. A model is proposed here where the frequency distribution of the number of experimental organ metastases is affected by Poisson statistics, and by stochastic variations in regional blood flow. The model predicts that the mean E (X) and variance var (X) of the number of metastases per organ should relate according to a power function,var (X)= E (X)(p)+E (X), where and p are the constants, and that the actual distribution has a Poisson-negative binomial form. This model was found consistent with the data derived from a meta-analysis of over 47 000 murine experimental metastases. This frequency distribution (together with knowledge of the size distribution for metastases and the fraction of clonogenic cells) could permit more accurate assessments for tumor control probabilities with adjuvant therapies.     

Analysis of heterogeneity in nonspecific PEGylation reactions of biomolecules

The compositional heterogeneity associated with polymer conjugation reactions of biomolecules is analyzed for the particular case of nonspecific PEGylation reactions. It is shown that the distribution of the number of PEG moieties grafted to biomolecules such as proteins is a binomial‐type function of two parameters—the reaction efficiency as well as the number of binding sites per biomolecule. The nature of this distribution implies that uniform compositions are favored for increasing number of coupling sites per biomolecule as well as for increasing efficiency of the modification process. Therefore, the binomial distribution provides a rationale for the pronounced heterogeneity that is observed for PEGylated small enzyme systems even at high coupling efficiencies. For the particular case of PEGylated trypsin it is shown that the heterogeneity results in a broad distribution of deactivation times that is captured by a stretched exponential decay model. The presented analysis is expected to apply to general modification processes of compounds in which partial functionalization of a fixed number of reactive sites is achieved by means of a nonspecific coupling reaction. © 2012 Wiley Periodicals, Inc. Biopolymers 99: 427–435, 2013.     

Sentinel node biopsy should be supplemented by axillary sampling in patients with small breast cancers

Axillary clearance provides important prognostic information but is associated with significant morbidity. Sentinel node biopsy can provide staging .141 patients with node negative early breast cancers-tumour size less than 1.5 cm measured clinically or by imaging had guided axillary sampling (sentinel lymph node biopsy in combination with axillary sampling). Four node axillary sampling improved the detection rate of axillary node metastases by 13.6% as compared to blue dye sentinel node biopsy alone. Positive sampled nodes strongly indicated the likelihood of further metastatic being revealed by axillary dissection (67%). Negative sampled nodes in combination with a positive sentinel node biopsy were associated with a much lower rate of further nodal involvement in the axillary clearance (8%).     

Measurement of primary tumor volume by PET–CT to evaluate risk of mediastinal nodal involvement in NSCLC patients with clinically negative N2 lymph nodes

Aim

The study aimed to determine a prognostic value of primary tumor volume measured on the basis of integrated positron emission tomography–computerized tomography (PET–CT) in terms of mediastinal nodal metastases (N2) prediction in non-small-cell lung cancer (NSCLC) patients with PET–CT N2 negative lymph nodes.

Methods

The records of 70 potentially operable NSCLC patients treated with surgical resection were analyzed. All patients underwent diagnostic, preoperative PET–CT, which was the basis for tumor volume calculations as well as the evaluation of N2 nodes status. The logistic regression analysis was employed to determine correlation between mediastinal nodal involvement and volume of primary tumor (izoSUV2.5 volume), that is the volume of primary tumor inside SUV 2.5 line, tumor histology, location (peripheral vs. central), hilar node status.

Results

A statistically significant correlation between mediastinal node involvement and izoSUV2.5 volume, tumor histology, locations peripheral vs. central and hilar node status was found. The risk of mediastinal lymph node metastasis is 24% for tumor volume of 100 cm³ and increases up to 40% for tumor volume of 360 cm³. An increase of tumor volume by 1 cm³ increases the risk of lymph node disease by 0.3%. Tumor histology adenocarcinoma vs. squamous cell carcinoma increases the risk of mediastinal lymph node involvement by 195%, location central vs. peripheral by 68% and hilar node involvement by 166%.

Conclusions

The study demonstrates that izoSUV2.5 volume of primary tumor may be considered as a prognostic factor in NSCLC patients, since it strongly correlates with mediastinal lymph node pathological status. This correlation is modified by primary tumor location, histology and hilar node involvement.     

Influence of parental density on the distribution pattern of eggs in the common cabbage butterfly,Pieris rapae crucivora

To investigate the relation between the distribution pattern of eggs and the parental density in the common cabbage butterfly, Pieris rapae crucivora, the countings of egg number per plant were made on both cabbage plants cultivated in the farm and planted in the net house in which the female butterflies were released at various densities. The frequency distribution of eggs fits well to the negative binomial excepting the cases where they agree withPoisson series, and the degree of aggregation expressed as the reciprocal of the parameter, 1/k, tends to decrease as the egg or parental density increases. At the same parental density, however, the distribution of eggs can be described by the negative binomial with a common parameter, k_c, regardless of the difference in the density of laid eggs. In the case where a single female butterfly lays eggs, the spatial pattern of egg distribution is always lean, while its frequencies conform toPoisson or the negative binomial series. This lean changes toward patchy with increasing the parental density. From these results, it is concluded that the degree of aggregation in the distribution of eggs decreases with the increase of the parental density.     

Spatial Analysis of Heterodera glycines Populations in Field Plots

Spatial heterogeneity in nematode population densities presents an obstacle to the precise determination of infestation levels. Three field plots were intensively sampled for soybean cyst nematode (Heterodera glycines Ich.) cysts before and after spring cultivation to quantify the spatial attributes of the population. Population density strata were detected running parallel to plant rows. Highest population densities before cultivation were found in the plant row and the middle furrow, Population density in the plant row averaged 26% higher and 4% lower than the whole-plot mean before and after cultivation, respectively. Cysts containing fewer than 25 eggs were not stratified, indicating that most were produced before the previous season. Sample population counts were fit to the negative binomial distribution model before cultivation, but distributions differed among plots. The Neyman type A and negative binomial distributions both fit the data after cultivation disturbed the soil. Population clusters 1-3 m long were detected in plant beds before cultivation. Heterogeneity in population density increased with plant row length after cultivation. Optimum plot length for minimal spatial heterogeneity in four-row mechanically tended field plots was estimated at 6 m after trimming plot ends.     

Radiation therapy for seminoma of the testis: results in British Columbia.

Between 1942 and 1978 radiation therapy was given to 362 patients with seminoma of the testis, 40 (11%) of whom had a history of maldescent of either testis. The disease was classified retrospectively according to the extent of the primary tumor, the involvement of the regional lymph nodes and the presence of distant metastases (the TNM system), and the results of treatment were analysed according to the classifications. Among the 275 patients referred for treatment at least 5 years before this analysis the 5-year survival rates were 87% overall, 96% for those with a T1 or T2 (relatively localized) tumour but no evidence of nodal involvement or distant metastases and 62% for the 24 with palpable or distant metastases at the time of clinical presentation. Of the 28 patients in whom the disease recurred 15 were successfully treated. A second primary testicular tumour developed in the contralateral testis of eight patients. The incidence of other cancers was not increased over the expected rate in the general male population of the same age.     

One‐inflation and unobserved heterogeneity in population size estimation

We present the one‐inflated zero‐truncated negative binomial (OIZTNB) model, and propose its use as the truncated count distribution in Horvitz–Thompson estimation of an unknown population size. In the presence of unobserved heterogeneity, the zero‐truncated negative binomial (ZTNB) model is a natural choice over the positive Poisson (PP) model; however, when one‐inflation is present the ZTNB model either suffers from a boundary problem, or provides extremely biased population size estimates. Monte Carlo evidence suggests that in the presence of one‐inflation, the Horvitz–Thompson estimator under the ZTNB model can converge in probability to infinity. The OIZTNB model gives markedly different population size estimates compared to some existing truncated count distributions, when applied to several capture–recapture data that exhibit both one‐inflation and unobserved heterogeneity.     

Adenovirus-mediated gene expression imaging to directly detect sentinel lymph node metastasis of prostate cancer

The accurate assessment of nodal involvement in prostate cancer is crucial to planning treatment, yet there is a shortage of noninvasive imaging techniques capable of visualizing nodal lesions directly. This study demonstrates the feasibility of using recombinant human adenoviral vectors to detect nodal metastases in a human prostate cancer model. This was achieved by the prostate-restricted expression of optical and positron emission tomography (PET) imaging reporter genes by the viral vector coupled with the innate lymphotropic properties of adenovirus. We show that peritumoral administration of these vectors results in the direct detection of reporter gene expression in metastatic lesions within sentinel lymph nodes. Notably, this approach parallels the current lymphoscintigraphy method but enables the direct PET visualization of sentinel lymph node metastases, eliminating the need for invasive lymphadenectomy. These findings may lead to more effective diagnostic and therapeutic strategies for individuals with advanced-stage prostate cancer.     

A comparative analysis on the distribution of nymphal populations of some leaf- and planthoppers on rice plant

The frequency distribution of the number of nymphs per hill of rice plant were analyzed for three species of rice leaf- and planthoppers, Nilaparvata lugens, Delphacodes striatella and Nephotettix cincticeps, based on the sampling data obtained during their last generations in the paddy field. For every species concerned, individual distributions were proved to be contagious and to fit well to the negative binomial distribution. Further, it was found that the value of negative binomial parameter k is so stable for same species that a single value of k is applicable for a series of counts with different means, whereas that k differs remarkably among different species: if the reciprocal of the weighted estimate of common k which is an adequate index measuring degree of contagiousness of the distribution, is compared among different species, it is higher in the order of Nilaparvata, Delphacodes and Nephotettix. The ecological and practical implication of constancy and heterogeneity within and among species was discussed respectively as to the value of parameter k.     

Microspatial heterogeneity in the distribution of ciliates in a small pond

Five transects of contiguous samples from the surface of a small pond and one transect from its bottom were collected in order to quantify microspatial heterogeneity in the distribution of ciliated protozoa. Examination of the frequency-abundance relations for these transects suggests that they can be approximated by negative binomial distributions with a commonk of 1.87. Contagiousness or crowding increases with population density.Mean patch size and mean interpatch distance were measured for 4 transects as 1.5 to 2 cm and 3 to 4 cm, respectively. This heterogeneity is suggested to arise from behavioral aggregation about discrete food sources and be very ephemeral.Blocking of adjacent contiguous samples was used to investigate the effect of sample size on the apparent correlation between the numbers of pairs of taxa. In all cases examined, taxa were relatively independent in their distribution at small sample sizes and became more negatively or positively associated as samples were combined. This may reflect that the small scale patches are essentially monospecific.     

科尔沁沙地草地植被恢复演替进程中群落优势种群空间分布格局研究

通过对处于流动沙地、半固定沙地和固定沙地等不同恢复演替阶段的群落的取样调查 ,研究了科尔沁沙地草地植被恢复进程中群落优势种群的空间分布格局及其动态变化。运用扩散系数、聚集指数、平均拥挤度、聚块性指数、Green指数、聚集强度、Poisson分布和负二项分布的 χ2 拟合检验等 7项指标 ,对群落优势种群的分布格局的研究结果基本一致 ,大多数物种的空间分布呈显著的聚集分布。在演替进程中种群格局强度的变化和群落总体聚集程度的变化与种群动态和群落结构的空间异质性相对应 ,较高的聚集程度是种群分布斑块化和群落结构的空间异质性的反映 ,随着演替进展 ,优势种的种群数量扩展 ,但种群分布的聚集强度下降 ,群落结构的空间异质性降低。在 7种测定分布格局的指标中 ,聚块性指数、Green指数和聚集强度是无量纲的指标 ,其大小不受种群大小的影响 ,其变化可以较好地指示格局强度本身的变化 ,并与种群动态和群落结构变化相联系     

Myosin types and fiber types in cardiac muscle. III. Nodal conduction tissue

The sinoatrial (SA) and atrioventricular (AV) nodes are specialized centers of the heart conduction system and are composed of muscle cells with distinctive morphological and electrophysiological properties. We report here results of immunofluorescence and immunoperoxidase studies on the bovine heart showing that a large number of SA and AV nodal cells share a distinct type of myosin heavy chain (MHC) which is not found in other myocardial cells and can thus be used as a cell-type-specific marker. The antibody used in this study was raised against fetal skeletal myosin and reacted with fetal skeletal but not with adult skeletal MHCs. Both atrial and ventricular fibers, as well as fibers of the ventricular conduction tissue were unlabeled by this antibody. Specific reactivity was exclusively seen in most cells in the central portions of the SA and AV nodes and rare cells in perinodal areas. However, a number of nodal cells, particularly those located in the peripheral nodal regions, were unreactive with this antibody. The myosin composition of nodal tissues was also explored using two antibodies reacting specifically with alpha-MHC, the predominant atrial isoform, and beta-MHC, the predominant ventricular isoform. Most nodal cells were reactive for alpha-MHC and a number of them also for beta-MHC. Variation in reactivity with the two antibodies was also observed in perinodal areas: at these sites a population of large fibers reacted exclusively for beta-MHC. These findings point to the existence of muscle cell heterogeneity with respect to myosin composition both in nodal and perinodal tissues.     

Inverse Sampling in Case Control Studies Involving a Rare Exposure

In case-control studies where the outcome is not uncommon but the exposure is rare, inverse sampling may be used to reduce the total number of subjects required to find a fixed number of exposed cases and controls. The sampling distribution is negative binomial rather than binomial. Logistic regression for adjustment of covariates may be implemented on the computer program GLIM by the appropriate use of macros. An example is given.