Species differences in carcinogenesis

The prognosis for carcinoma of the oesophagus is generally dismal especially when patients present late. Any clues to early diagnosis and management and identification of rapidly progressive variants are therefore helpful. Reports and review of the literature are presented with respect to four unusual cases of oesophageal carcinoma treated in the University of Ilorin Teaching Hospital in 1985 and 1986. Four men aged 59, 60, 55 and 60 years respectively presented with multiple polypoid carcinoma of the oesophagus, malignant oesophago-bronchial fistula at the level of the left main stem bronchus, achalasia co-existing with oesophago-gastric carcinoma and a small focus of carcinoma of the distal thoracic oesophagus presenting with widespread thoracic metastases and malignant pleural effusion mimicking advanced bronchogenic carcinoma. The unusual clinico-pathological features with the autopsy findings in the last case can influence diagnosis, management and prognosis of oesophageal cancer in general and of such cancer associated with pre-malignant conditions like achalasia and oesophageal polyps in particular.     

Species differences in the physical and transport properties of airway secretions

Four cases of severe Lepiota poisoning, including three which developed toxic fulminant hepatitis treated by orthotopic hepatic transplantation, are reported here. The toxicity of the Lepiota is discussed as well as the indications for hepatic transplantation in poisonings due to amatoxin-containing mushrooms.     

Social isolation rearing: Species differences in behavior of macaque monkeys.

Social and nonsocial behaviors of 16 infant rhesus ( Macaca mulatta ) and 25 pigtail ( M. nemestrina ) monkeys reared in total social isolation were compared with those of 51 socialized controls. As a species, pigtail monkeys were more social, more passive, and less exploratory. Rhesus isolates exhibited a "typical" syndrome of abnormal behavior to a much greater extent than pigtail isolates. These results question the generality of rhesus total isolate behavior as a model for some human problems and illustrate the need to study many species, even among closely related nonhuman primates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Species differences in the metabolic activation of tamoxifen into genotoxic derivatives: risk assessment in women

A prospective study was conducted comparing the sensitivity of the pp65 antigenemia assay (AGA) to that of the shell-vial culture (SVC) inoculated with increasing quantities of polymorphonuclear leukocytes (PMNLs) in the detection of cytomegalovirus (CMV) in peripheral blood. From the cellular suspension, three SVCs were inoculated with 200,000, 400,000, and 800,000 PMNLs, respectively. Of the 201 patients studied, 67 (31.9%) had positive results in one of the two analytic tests (AGA or SVC). In this group, 13 (19.4%) presented a negative AGA assay; 13 (19.4%) an AGA of 1; 13 (19.4%) an AGA of between 2 and 5; and 28 (41.8%) an AGA with a value > 6 PMNL-positive x 100,000 PMNLs. The SVC inoculated with 200,000 PMNLs detected the presence of CMV in 42 cases (62.6%); 55 (82%) with 400,000; and 64 (95.5%) with 800,000. Statistically significant differences were observed between the isolation capacities of the SVC inoculated with 200,000 and 400,000, and the SVC inoculated with 800,000 PMNLs (p = 0.0001). In the comparison of the overall sensitivity of the AGA with that of the SVC with 200,000, the AGA was found to be significantly more sensitive (p = 0.0052). When comparing with the SVC with 400,000 PMNLs, the two techniques were found to be equally sensitive; and in the comparison with the SVC with 800,000, the culture displayed a greater detection sensitivity (p = 0.0023). According to these results, it seems evident that the increase in the absolute number of PMNLs inoculated in the SVC leads to a significant increase in the sensitivity of the SVC in the detection of low-level viremia by CMV.     

Species differences in executive function correlate with hippocampus volume and neocortex ratio across nonhuman primates.

A persistent debate in behavioral research is whether brain size or architecture relates to cognitive performance. A growing body of evidence has demonstrated correlations between brain size and ecological and behavioral tasks. These studies are premised on a causal link between brain size and cognitive function, although this association has little empirical backing. We show, for a set of 46 species from 17 primate genera, that competence on a series of eight executive function cognitive tasks both correlate across tasks and with brain size and architecture across species. Our model selection approach showed that, although several measures of brain component volumes are significantly associated with performance, hippocampus size is the best predictor of overall performance. The best performing model also includes total brain size and relative neocortex size. Additionally, absolute measures are much more predictive of performance than relative measures of brain and brain component size. These results are consistent with the hippocampus' role in learning, and the executive brain (neocortex) being important for problem solving and consolidation. Our findings challenge and extend those of previous analyses by clarifying the relationship between overall brain size and specific regional volumes. They also suggest that commonly used indices of encephalization, such as residuals of brain volume regressed on body size, may confound rather than clarify matters. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Species differences in V?a receptor gene expression in monogamous and nonmonogamous voles: Behavioral consequences.

Arginine vasopressin modulates a number of species-typical social behaviors, including social memory in rats, scent marking and aggressive behavior in hamsters, and partner preference formation and paternal behavior in monogamous rodents. The distribution of V?a receptor binding sites in the brain varies greatly among species. Using in situ hybridization in 2 species of voles with strikingly different patterns of V?a binding sites and social behaviors, the authors demonstrate that differences in V?a receptor binding sites are due to species differences in regional V?a receptor gene expression. It is then demonstrated that the differences in receptor gene expression are associated with species differences in behavioral response to centrally administered vasopressin. Together, these data suggest that the phylogenetic plasticity of central neurohypophyseal peptide receptor expression may contribute to the evolution of species-typical social behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory frequency discrimination in primates: Species differences (Cercopithecus, Macaca, Homo).

Auditory frequency difference limens (DLs) at 2 kHz were measured in Old World monkeys (Cercopithecus, Macaca) and humans using a go/no-go repeating standard procedure and positive reinforcement operant conditioning techniques. Quantitative and qualitative differences occurred between monkey and human sensitivity. Best DLs for monkeys were 20–60 Hz, and for humans they were 3–4 Hz. Monkey sensitivity decreased as sensation level increased from 30 to 70 dB, whereas human sensitivity increased. Sensitivity differences also occurred in the various monkey species. Cercopithecus monkeys were generally more sensitive to frequency decrements, whereas Japanese macaques were more sensitive to frequency increments, as were humans. Results are related to other comparative psychoacoustic data and primate vocal communication, including human speech. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Species differences in brain adenosine A1 receptor pharmacology revealed by use of xanthine and pyrazolopyridine based antagonists

1. The pharmacological profile of adenosine A1 receptors in human, guinea-pig, rat and mouse brain membranes was characterized in a radioligand binding assay by use of the receptor selective antagonist, [3H]-8-cyclopentyl-1,3-dipropylxanthine ([3H]-DPCPX). 2. The affinity of [3H]-DPCPX binding sites in rat cortical and hippocampal membranes was similar. Binding site affinity was higher in rat cortical membranes than in membranes prepared from guinea-pig cortex and hippocampus, mouse cortex and human cortex. pKD values (M) were 9.55, 9.44, 8.85, 8.94, 8.67, 9.39 and 8.67, respectively. The binding site density (Bmax) was lower in rat cortical membranes than in guinea-pig or human cortical membranes. 3. The rank order of potency of seven adenosine receptor agonists was identical in each species. With the exception of 5'-N-ethylcarboxamidoadenosine (NECA), agonist affinity was 3.5-26.2 fold higher in rat cortical membranes than in human and guinea-pig brain membranes; affinity in rat and mouse brain membranes was similar. While NECA exhibited 9.3 fold higher affinity in rat compared to human cortical membranes, affinity in other species was comparable. The stable GTP analogue, Gpp(NH)p (100 microM) reduced 2-chloro-N6-cyclopentyladenosine (CCPA) affinity 7-13.9 fold, whereas the affinity of DPCPX was unaffected. 4. The affinity of six xanthine-based adenosine receptor antagonists was 2.2-15.9 fold higher in rat cortical membranes compared with human or guinea-pig membranes. The rank order of potency was species-independent. In contrast, three pyrazolopyridine derivatives, (R)-1-[(E)-3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl) acryloyl]-2-piperidine ethanol (FK453), (R)-1-[(E)-3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl) acryloyl]-piperidin-2-yl acetic acid (FK352) and 6-oxo-3-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)-1(6H)-pyridazinebutyric acid (FK838) exhibited similar affinity in human, guinea-pig, rat and mouse brain membranes. pKi values (M) for [3H]-DPCPX binding sites in human cortical membranes were 9.31, 7.52 and 7.92, respectively. 5. Drug affinity for adenosine A2A receptors was determined in a [3H]-2-[4-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamido ade nosine ([3H]-CGS 21680) binding assay in rat striatal membranes. The pyrazolopyridine derivatives, FK453, FK838 and FK352 exhibited pKi values (M) of 5.90, 5.92 and 4.31, respectively, compared with pKi values of 9.31, 8.18 and 7.57 determined in the [3H]-DPCPX binding assay in rat cortical membranes. These novel pyrazolopyridine derivatives therefore represent high affinity, adenosine A1 receptor selective drugs that, in contrast to xanthine based antagonists, exhibit similar affinity for [3H]-DPCPX binding sites in human, rat, mouse and guinea-pig brain membranes.     

Species differences in ontogeny of memory: Indirect support for neural maturation as a determinant of forgetting.

Studied the development of long-term memory in 150 Sprague-Dawley rats and 80 male Hartley guinea pigs as a function of age, using active escape and passive avoidance tasks. Memory increased with age in the rats but did not change in the guinea pigs. It is concluded that neurological maturity at the time of original learning appears to be a major determinant of long-term memory. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Species differences in vasopressin receptor binding are evident early in development: comparative anatomic studies in prairie and montane voles

Monogamous prairie voles (Microtus ochrogaster) and promiscuous montane voles (Microtus montanus) exhibit remarkable differences in the distribution of vasopressin (AVP) receptors in the adult brain. This difference in receptor distribution is associated with species differences in the behaviors, including pair bond formation and paternal care, found selectively in the monogamous vole. To investigate a potential mechanism for this species difference in AVP receptors, the present study examined the ontogeny of receptor binding in the two species to determine whether the adult maps arose from a shared pattern in development. By using 125I-linear-AVP, which is a selective high-affinity ligand for the V1a receptor, we found early appearance and transient expression of AVP receptor binding during postnatal development in both species. However, the ontogenetic patterns of regional AVP receptor binding were species specific. In the diagonal band, the bed nucleus of the stria terminalis, and the central nucleus of the amygdala, prairie voles had higher AVP receptor binding at birth than montane voles, and this difference persisted with little variation into adulthood. In these areas, therefore, species differences in AVP receptor binding appeared to be determined primarily by genetic or prenatal factors. In the lateral septum, both species had low levels of AVP receptor binding at birth. Thereafter, the binding increased rapidly in montane voles, but it remained unchanged in prairie voles. In the cingulate cortex, AVP receptor binding in prairie voles showed a peak in early development with a subsequent decline and reached the adult level at weaning, whereas the binding in montane voles remained unchanged into adulthood. A similar but opposite pattern was found in the frontoparietal cortex, in which AVP receptor binding showed an early peak in montane voles but did not change significantly in prairie voles. These results demonstrate that 1) species differences in regional AVP receptor binding are evident in the early postnatal period and, in several areas, may be determined by genetic or prenatal factors, and 2) AVP may target brain areas differently in infant and adult prairie and montane voles and, thus, could exert differential effects on the organization of the central nervous system in the two species of voles.     

Species differences in regional patterns of 3H-8-OH-DPAT and 3H-zolpidem binding in the rat and human brain

A series of brief office counseling interventions for the prevention and treatment of violence is reviewed in this article. Primary prevention strategies throughout the pediatric age span cover topics from gun storage to nonviolent handling of a potential street fight. Secondary prevention strategies deal with patients who have been injured by violence or patients who engage in street violence, weapon carrying, or dating violence.     

Species differences in size discrimination in the paracellular pathway reflected by oral bioavailability of poly(ethylene glycol) and D-peptides

Animal models are frequently used to aid prediction of intestinal absorption in humans. However, there is little comparative quantitative information on species differences in paracellular permeation, which is an important route for oral absorption of small to medium-sized hydrophilic drug molecules. This study addresses this issue by comparing the molecular mass (MM) dependency in oral bioavailability between rat and dog of poly(ethylene glycol) (PEG), a polydispersed model mixture commonly used to characterize paracellular absorption, and of a series of eight D-peptides (based on D-phenylalanine). Fasted rats and dogs received PEG (400/900) and the D-peptides (MM 236-406 Da), orally and intravenously, with total 24-48 h urine collection to estimate oral bioavailability. After HPLC separation, the individual PEG oligomers and D-peptides were determined using radiometric detection, for radiolabeled material, and LC-MS, for unlabeled (PEG) material. All compounds were predominantly excreted unchanged following intravenous administration. After oral administration, the predominant peak in the radiochromatogram was unchanged material, indicating stability of the compounds in the gastrointestinal tract. A clear molecular mass dependency in oral bioavailability was seen with both series, but with absorption much greater in dog than rat. Thus, for PEG in rat, bioavailability decreased sharply from 79 to around 2% with increasing MM between 282 and 591 Da, and then tapered to around 1. 5% up to 1295 Da. Whereas in dog, bioavailability remained around 100% for oligomers up to 600 Da and then decreased quite sharply with increasing MM, tending to plateau around 13% beyond 900 Da. Likewise, for the d-peptides in rat, bioavailability decreased from 30 to 1% with increasing MM between 236 and 406 Da, whereas in dog it was 100%, declining to 16% over the same molecular range. This species difference appears to be due to a larger pore size and greater frequency of pores in the paracellular pathway of dog compared to rat. Furthermore, on the basis of comparison with literature data for PEG and selected drugs, rat would appear to be a better predictor than dog of absorption of hydrophilic compounds in human.     

Species differences in the expression of major histocompatibility complex class II antigens on coronary artery endothelium: implications for cell-mediated xenoreactivity

BACKGROUND: There is controversy in the literature as to whether swine coronary endothelium expresses major histocompatibility complex (MHC) class II antigens constitutively. METHODS: Because this issue has implications for cell-mediated human anti-swine xenogeneic responses, we stained tissue sections from human, pig, rat, and mouse hearts with the anti-class II monoclonal antibody ISCR3, which has a similar specificity and titer when binding to human, porcine, and rodent class II molecules. RESULTS: Immunoperoxidase staining of human and porcine hearts with ISCR3 resulted in a dense reaction on the coronary endothelium of epicardial arteries, intramuscular arterioles, and capillaries. In contrast, the coronary endothelium of rat and mouse hearts did not stain with ISCR3. When freshly harvested porcine aortic endothelial cells were placed in culture, class II MHC antigen expression was lost within three to four passages. CONCLUSIONS: Thus, using a single antibody with cross-species reactivities, we demonstrate that swine coronary endothelium, unlike rodent coronary arteries, expresses similar basal amounts of class II MHC antigens to human coronary vessels. The constitutive expression of class II MHC antigens on swine coronary artery endothelium may contribute to host T cell-mediated xenogeneic responses in clinical pig-to-human cardiac xenotransplantation and thus become a target for therapeutic intervention.     

Species differences in the glutathione transferase GSTT1-1 activity towards the model substrates methyl chloride and dichloromethane in liver and kidney

Glutathione transferase (GST) GSTT1-1 is involved in the biotransformation of several chemicals widely used in industry, such as butadiene and dichloro methane DCM. The polymorphic hGSTT1-1 may well play a role in the development of kidney tumours after high and long-term occupational exposure against trichloroethylene. Although several studies have investigated the association of this polymorphism with malignant diseases little is known about its enzyme activity in potential extrahepatic target tissues. The known theta-specific substrates methyl chloride (MC) dichloromethane and 1,2-epoxy-3-(p-nitrophenoxy)propane (EPNP) were used to assay GSTT1-1 activity in liver and kidney of rats, mice, hamsters and humans differentiating the three phenotypes (non-conjugators, low conjugators, high conjugators) seen in humans. In addition GSTT1-1 activity towards MC and DCM was determined in human erythrocytes. No GSTT1-1 activity was found in any tissue of non-conjugators (NC). In all organs high conjugators (HC) showed twofold higher activity towards MC and DCM than low conjugators (LC). The activity in human samples towards EPNP was too close to the detection limit to differentiate between the three conjugator phenotypes. GSTT1-1 activity towards MC was two to seven-times higher in liver cytosol than in kidney cytosol. The relation for MC between species was identical in both organs: mouse > HC > rat > LC > hamster > NC. In rats, mice and hamsters GSTT1-1 activity in liver cytosol towards DCM was also two to seven-times higher than in the kidney cytosol. In humans this activity was twice as high in kidney cytosol than in liver cytosol. The relation between species was mouse > rat > HC > LC > hamster > NC for liver, but mouse > HC > LC/rat > hamster/NC for kidney cytosol. The importance to heed the specific environment at potential target sites in risk assessment is emphasized by these results.     

Species and sex differences in substrate preference and tongue flick rate in three sympatric species of water snakes (Nerodia).

Tested isolation-reared sympatric water snakes (Nerodia r. rhombifera, N. c. cyclopion, and N. fasciata confluens) in a balanced 2-choice design to determine preference between clean and same-sex conspecific-soiled gravel substrates. Ss included 8 snakes (4 of each sex) of each species. Time spent on each substrate, types of tongue flicking behavior, tail vibration, defecation, and head rubbing were recorded. Species and sex differences were found in the relative time spent on the 2 substrates. Both sexes of N. rhombifera preferred the clean substrate, whereas both sexes of N. cyclopion preferred the soiled substrate, although the difference in time spent on the substrates was small for males. N. fasciata sexes differed in their preference, with the females preferring the soiled substrate and the males preferring, but not so strongly, the clean substrate. The frequencies of the 4 types of tongue extensions differed across species and sexes, with "air" tongue flicks accounting for the most variance. A lower total rate of tongue flicking occurred when the snakes were on the preferred substrate. These species and sex differences may help minimize competition due to dietary overlap between N. rhombifera and N. cyclopion, and between male and female N. fasciata. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determinants of individual differences and gender differences in knowledge.

The authors investigated the abilities, self-concept, personality, interest, motivational traits, and other determinants of knowledge across physical sciences/technology, biology/psychology, humanities, and civics domains. Tests and self-report measures were administered to 320 university freshmen. Crystallized intelligence was a better predictor than was fluid intelligence for most knowledge domains. Gender differences favoring men were found for most knowledge domains. Accounting for intelligence reduced the gender influence in predicting knowledge differences. Inclusion of notability predictors further reduced the variance accounted for by gender. Analysis of Advanced Placement test scores largely supported the results of the knowledge tests. Results are consistent with theoretical predictions that development of intellect as knowledge results from investment of cognitive resources, which, in turn, is affected by a small set of trait complexes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

物种多样性的研究进展

在总结物种多样性与群落结构、群落生境因子及群落生产力的关系基础上,进一步综述了物种多样性在植被恢复和重金属污染治理中的应用.