Repeated post trial administration of vasopressin impairs subsequent Differential Reinforcement of Low rates (DRL) performance

Twenty-six male rats, maintained on a 23-h food deprivation regime, were trained on a DRL learning schedule. During pretraining (CRF) rats were placed in two groups according to speed in obtaining the criterion (good and poor learners). The performance of good and poor learners, injected with lysine vasopressin (LVP) immediately after each training session, was compared with that of control good and poor learners injected with saline. During the first DRL 20 stage, injected rats had fewer reinforcements than control rats. Fifty-five days later, during reacquisition of DRL 20, LVP rats again had fewer reinforcements, especially those which were formerly good learners in the CRF stage. Nonetheless, treated rats were able to shift their rate of responding from high to low frequency. A reduction of the minimal interresponse time to 16 s showed that LVP rats were able to adapt to this condition and that, in a further DRL 20 stage, the difference between the two groups was no longer significant.The results are discussed in terms of a modification of the behavioral expression of a learned response, without a specific action on memory processes.     

Form and patterning of anterior tooth wear among aboriginal human groups

Form and severity of dental attrition was assessed in aboriginal human groups including hunter-gatherers (Eskimos, Australians) and those with dependence to a varying degree on food production (Southwest U.S. and Ohio American Indians). Wear on anterior teeth was both relatively and absolutely greater in the hunter-gatherers, as indicated by comparisons of wear on anterior and posterior teeth which come into occlusion at roughly the same time. Distinct differences in form of anterior wear were also apparent: The hunter-gatherers exhibited steadily increasing incidences of labially rounded wear with greater functional age, while the food-producing groups showed little or no rounding but instead high frequencies of heavily cupped wear (especially in those with premature loss of posterior teeth). These differences were attributed to nonmasticatory utilization of the front teeth in hunter-gatherers and to employment of the anterior teeth in masticatory (grinding) activities necessitated by large-scale molar loss in food producers.     

Retention improvement by topical application of uridine monophosphate into different brain areas

This study aimed to demonstrate the effect of uridine monophosphate (UMP) on the consolidation of a brightness-discrimination reaction after topical application of this RNA precursor into the hippocampus, the neocortex or the mesencephalic reticular formation (MRF). Thirty minutes before the rats started their training in a Y-chamber, UMP was injected into each animal through cannula implanted into the particular brain area. When injected into hippocampus or MRF UMP exerted no influence on acquisition, but after epidural UMP injection an impairment of acquisition was observed. After intrahippocampal or epidural UMP application the retention test carried out 48 hour after training showed a significant improvement in retention performance, whereas UMP injection into MRF showed no influence on retention. Consequently, the retention-improving effect of UMP is probably not induced by activation of ascending neuronal systems.     

NOD/SCID-GAMMA Mice Are an Ideal Strain to Assess the Efficacy of Therapeutic Agents Used in the Treatment of Myeloma Bone Disease

Animal models of multiple myeloma vary in terms of consistency of onset, degree of tumour burden and degree of myeloma bone disease. Here we describe five pre-clinical models of myeloma in NOD/SCID-GAMMA mice to specifically study the effects of therapeutic agents on myeloma bone disease. Groups of 7–8 week old female irradiated NOD/SCID-GAMMA mice were injected intravenously via the tail vein with either 1x10⁶ JJN3, U266, XG-1 or OPM-2 human myeloma cell lines or patient-derived myeloma cells. At the first signs of morbidity in each tumour group all animals were sacrificed. Tumour load was measured by histological analysis, and bone disease was assessed by micro-CT and standard histomorphometric methods. Mice injected with JJN3, U266 or OPM-2 cells showed high tumour bone marrow infiltration of the long bones with low variability, resulting in osteolytic lesions. In contrast, mice injected with XG-1 or patient-derived myeloma cells showed lower tumour bone marrow infiltration and less bone disease with high variability. Injection of JJN3 cells into NOD/SCID-GAMMA mice resulted in an aggressive, short-term model of myeloma with mice exhibiting signs of morbidity 3 weeks later. Treating these mice with zoledronic acid at the time of tumour cell injection or once tumour was established prevented JJN3-induced bone disease but did not reduce tumour burden, whereas, carfilzomib treatment given once tumour was established significantly reduced tumour burden. Injection of U266, XG-1, OPM-2 and patient-derived myeloma cells resulted in less aggressive longer-term models of myeloma with mice exhibiting signs of morbidity 8 weeks later. Treating U266-induced disease with zoledronic acid prevented the formation of osteolytic lesions and trabecular bone loss as well as reducing tumour burden whereas, carfilzomib treatment only reduced tumour burden. In summary, JJN3, U266 or OPM-2 cells injected into NOD/SCID-GAMMA mice provide robust models to study anti-myeloma therapies, particularly those targeting myeloma bone disease.     

Erectile Function Restoration After Repair of Resected Cavernous Nerves by Adipose-Derived Stem Cells Combined with Autologous Vein Graft in Rats

Cavernous nerve (CN) injury is the main cause of erectile dysfunction (ED) following radical prostatectomy. The recovery of erectile function following this procedure remains challenging. Here, we investigated the ability of adipose-derived stem cells (ADSCs) combined with autologous vein graft to improve erectile function in a rat model of bilateral long CN resection. Sprague–Dawley rats (n = 36) were randomized into four groups. Group A underwent sham operation. In Groups B, C, and D, an 8-mm segment of CN was excised bilaterally. In Group B and C, a 10-mm segment of autologous saphenous vein was interposed bilaterally at the site of injury, and the two nerve stumps were inserted into the vein lumen. 50 μL ADSCs were injected into each vein in Group B, and 50 μL of phosphate-buffered saline was injected in Group C. Group D underwent no repair. Erectile function assessed after 3 months by measuring intracavernosal pressure demonstrated significant recovery in erectile function in Group B with minimal recovery in Group C or D. Immunohistochemical staining showed that the nNOS-positive area was significantly larger in Group B than in Group D. ADSCs combined with autologous vein graft treatment had beneficial effects on the smooth muscle/collagen ratio in the corpus cavernosum. This procedure, therefore, provided a means of regenerating CN tissue and restoring autonomic erectile function after long bilateral CN resection (0.8 cm) in rats.     

The effects of pressure on yeast cytochrome c peroxidase

The effects of pressure on cytochrome c peroxidase [CcP(FeIII)], its cyano derivative (CcP X CN) and its enzyme-substrate complex (ES) have been studied. The effects of pressure on the binding of the substrate analog porphyrin cytochrome c (porphyrin c) to CcP X CN and ES have also been studied. High pressure causes CcP(FeIII) to undergo a high-spin to low-spin transition but has no detectable effect on either CcP X CN, which is already low spin, or on ES. The low-spin CcP(FeIII) structure at pressure is similar to the low-spin form at low temperature and the low-spin form of horseradish peroxidase at high pressure. delta V degree associated with the spin equilibrium is about 30 ml/mol and is independent of temperature. delta G degree is small, 4.7 kJ/mol at 0 degree C, while delta H degree is 14.2 kJ/mol at 1 bar (100 kPa). Pressure has no detectable effect on the binding equilibria of mixtures of CcP X CN plus porphyrin c or ES plus porphyrin c. This indicates that the interaction of CcP and porphyrin c results in little or no volume change; the same is true in the case of cytochrome c oxidase and porphyrin c.     

INJECTION OF 6-HYDROXYDOPAMINE AND HYDROGEN PEROXIDE INTO THE SUBSTANTIA NIGRA AND LATERAL VENTRICLE OF THE CAT: SPECIFIC AND NONSPECIFIC EFFECTS ON STRIATAL BIOGENIC AMINES1

Attempting to clarify the mechanism by which intracerabral injection of 6-hydroxydopamine (60HDA) reduces catecholamines in the caudate nucleus (CN), we have tested two hypotheses: (1) 60HDA specifically attacks catecholaminergic neurons; (2) 60HDA liberates hydrogen peroxide (H₂O₂) which destroys neurons indiscriminately. To this end, we have injected high or low doses of 60HDA or equimolar amounts of H₂O₂ stereotaxically into the substantia nigra (SN) or the lateral ventricle of cats and have placed electrocoagulative lesions in the SN. We determined the CN levels of dopamine (DA), norepinephrine (NE) and serotonin (5HT) 7-10 days later. Nigral injections of high doses (8 μ mol) of either agent or low doses (80 nmol) of 60HDA decreased both DA and NE and induced similar histologic damage in the SN with neuronal drop-out at the periphery of the lesions. Injection of 80 nmol of H₂O₂ into the SN did not decrease CN amine levels and did not produce histologic damage in the SN. Electrocoagulation of the SN decreased CN DA and NE, but the histologic lesions failed to show any peripheral neuronal drop-out. Ventricular injections of high doses (16 μmol) of 60HDA or H₂O₂ reduced not only DA and NE but also 5HT levels in the ipsilateral CN. Low intraventricular doses (0-16 μmol) of 60HDA decreased only DA and NE without affecting 5HT levels in the CN whereas 0.16 μmol of H₂O₂ had no effect on any of the CN amines. The catecholamine-depleting effects of low doses (80 nmol) of 60HDA were significantly potentiated by inhibiting brain monoamine oxidase by 90 percent or more at the time and site of injection of 60HDA. These results suggest that the extracellular liberation of H₂O₂ from 60HDA could explain some possibly nonspecific effects of high doses of 60HDA; at lower doses, however, 60HDA may act via selective uptake into catecholaminergic neurons with subsequent intracellular release of H₂O₂.     

An in situ assessment of the routes and extents of colonisation of the mouse embryo by embryonic stem cells and their descendants

An embryonic stem (ES) cell line stably expressing lacZ under the control of an endogenous promoter has been isolated and used as a marker to follow the fate of ES cells injected into blastocysts and morulae, before midgestation. The results show a multisite pattern of blastocyst colonization by ES cells deposited into the blastocoel cavity and a low degree of mingling between ES cells and ICM cells. Furthermore, analysis of dispersal of ES cell descendants in postimplantation chimaeric embryos showed that colonization can be highly variable from one region of the embryo to another. In contrast, a high and reproducible degree of chimaerism was obtained when the ES cells were injected at the morula stage prior to ICM formation.     

Determination of citalopram and escitalopram together with their active main metabolites desmethyl(es-)citalopram in human serum by column-switching high performance liquid chromatography (HPLC) and spectrophotometric detection

We established a method for automated quantitative analysis of (es-)citalopram and desmethyl(es-)citalopram in serum using column-switching high performance liquid chromatography (HPLC). For sample clean-up serum was injected onto a LiChrospher CN 20 microm precolumn using 8% acetonitrile in deionized water. Drugs were eluted by back-flush flow onto the analytical column (LiChrospher CN 5 microm) at a flow rate of 1.5 ml/min with phosphate buffer 8 mmol/l pH 6.4/acetonitrile (50/50, v/v). Haloperidol was used as internal standard. Analytes were detected by ultraviolet spectrophotometry at 210 nm. Detection limit of (es-)citalopram was 6 ng/ml. The method was found to be suitable for therapeutic drug monitoring of patients treated with citalopram or escitalopram.     

High resistance/low repetition vs. low resistance/high repetition training: effects on performance of trained cyclists

In order to investigate the effects of a resistance training modality on cycling performance, 23 trained club-level cyclists were placed into high resistance/low repetition (H-Res), low resistance/high repetition (H-Rep), or cycling-only groups for a 10-week program. All 3 groups followed the same cycling plan, but the H-Res and H-Rep groups added resistance training. Testing pre and post consisted of a graded incremental lactate profile test on an ergometer, with blood lactate being sampled. VO2 values were measured to determine economy. Maximum strength testing of 4 strength exercises targeting the lower extremity musculature was conducted with the H-Res and H-Rep groups. There were significant gains in all 4 resistance training exercises (p < 0.05) for both H-Res and H-Rep, with the H-Res group having significantly greater gains than the H-Rep group had in the leg press exercise (p < 0.05). There were, however, no significant group x training differences (p > 0.05) found between the 3 training groups on the cycling test in lactate values or economy. It appears that for this population of cyclists, neither H-Res nor H-Rep resistance training provided any additional performance benefit in a graded incremental cycling test when compared with cycling alone over a training time of this length. It is possible that with this population, various factors such as acute fatigue, strength, and aerobic gains from the cycling training, in addition to well-developed bases of strength and conditioning from previous training, reduced differences between groups in both strength gains and cycling performance.     

Seed traits,fatty acid profile and genetic diversity assessment in <Emphasis Type="Italic">Pongamia pinnata</Emphasis> (L.) Pierre germplasm

Phenotypic variation of important seed traits like seed length, seed breadth, seed thickness, 100 seed weight and seed oil content were recorded in a total of 157 collected accessions of Pongamia. Out of these, fatty acid profiles of 38 accessions selected based on their high and low oil content was analyzed. Fatty acid profile revealed high variability in stearic, oleic and linoleic acid which varied from 0.42 to 10.61 %, 34.34 to 74.58 %, and 7.00 to 31.28 % respectively. Variations in palmitic and linolenic acid were small. Iodine value, saponification number and cetane number (CN) of fatty acid methyl esters (FAME) of seed oil ranges from 186.99 to 201.25, 81.13 to 108.19 and 46.16 to 56.47 respectively. Fatty acid compositions, degree of unsaturation and CN are the important parameters, which are used to determine quality of FAME were used as biodiesel. Some of the Pongamia accessions identified were higher in oil content while some accessions showed higher degree of unsaturation and a few of them had CN values higher than 55. Genetic diversity analysis with six TE-AFLP primers generated a total of 334 bands out of which 174 (52.10 %) were polymorphic. The genetic similarity ranged from 0.11 to 0.47. These findings clearly showed high level of genetic diversity and all economically desirable traits were not present in a single genotype of Pongamia. All these traits could be selected from these CPTs and transfer to a single elite variety through selection and breeding programme and could be utilized for large scale multiplication and plantation to produce high quantity and quality biodiesel in future.     

Morphology of neurons cultured from subdivisions of the mouse cochlear nucleus

This study was designed to characterize the dendritic organization of cochlear nucleus (CN) cells grown in primary cell culture and to assess differences among cultures grown from different regions of CN. Cultures were prepared from postnatal mice and processed using microtubule-associated protein 2 (MAP2) or gamma-aminobutyric acid (GABA) immunohistochemistry. CN neurons were successfully cultured from preparations grown from either the anteroventral subdivision of the nucleus (AVCN), the posterior region [posteroventral (PVCN) and dorsal (DCN) subnuclei], or the whole CN, although the cultured neurons did not exhibit complex dendritic patterns characteristic of CN neurons in vivo. Neurons cultured from the entire nucleus exhibited an increased rate of survival compared to those cultured from either the anterior or posterior regions, although similar types of cells were observed in all preparations. The majority of cultured CN neurons were GABA-positive and had soma areas that were similar to the areas of immature GABAergic neurons measured in CN sections. Small cells (soma areas or=120 microm(2)) were also present in significant numbers. Overall, CN cultures consisted of a heterogeneous population of neurons that had less elaborate dendritic organizations than cells of corresponding size that have been described in adult animals in vivo.     

Multi-Layer Self-Nanoemulsifying Pellets: an Innovative Drug Delivery System for the Poorly Water-Soluble Drug Cinnarizine

Beside their solubility limitations, some poorly water-soluble drugs undergo extensive degradation in aqueous and/or lipid-based formulations. Multi-layer self-nanoemulsifying pellets (ML-SNEP) introduce an innovative delivery system based on isolating the drug from the self-nanoemulsifying layer to enhance drug aqueous solubility and minimize degradation. In the current study, various batches of cinnarizine (CN) ML-SNEP were prepared using fluid bed coating and involved a drug-free self-nanoemulsifying layer, protective layer, drug layer, moisture-sealing layer, and/or an anti-adherent layer. Each layer was optimized based on coating outcomes such as coating recovery and mono-pellets%. The optimized ML-SNEP were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), in vitro dissolution, and stability studies. The optimized ML-SNEP were free-flowing, well separated with high coating recovery. SEM showed multiple well-defined coating layers. The acidic polyvinylpyrrolidone:CN (4:1) solution presented excellent drug-layering outcomes. DSC and XRD confirmed CN transformation into amorphous state within the drug layer. The isolation between CN and self-nanoemulsifying layer did not adversely affect drug dissolution. CN was able to spontaneously migrate into the micelles arising from the drug-free self-nanoemulsifying layer. ML-SNEP showed superior dissolution compared to Stugeron® tablets at pH 1.2 and 6.8. Particularly, on shifting to pH 6.8, ML-SNEP maintained >?84% CN in solution while Stugeron® tablets showed significant CN precipitation leaving only 7% CN in solution. Furthermore, ML-SNEP (comprising Kollicoat® Smartseal 30D) showed robust stability and maintained >?97% intact CN within the accelerated storage conditions. Accordingly, ML-SNEP offer a novel delivery system that combines both enhanced solubilization and stabilization of unstable poorly soluble drugs.     

Excitatory neural control of posterograde heartbeat by the frontal ganglion in the last instar larva of a lepidopteran, Bombyx mori

The frontal ganglion of the silkworm (Bombyx mori) gives rise to a visceral nerve, branches of which include a pair of anterior cardiac nerves and a pair of the posterior cardiac nerves. Forward-fill of the visceral nerve with dextran labeled with tetramethyl rhodamine shows the anterior cardiac nerves innervate the anterior region of the dorsal vessel. Back-fill of the anterior cardiac nerves with Co²⁺ and Ni²⁺ ions and the fluorescent dye reveals that the cell bodies of two motor neurons are located in the frontal ganglion. Injection of 5, 6-carboxyfluorescein into the cell body of an identified motor neuron shows that the neuron gives rise to an axon running to the visceral nerve. Unitary excitatory junctional potentials (EJPs) were recorded from a myocardial cell at the anterior end of the heart. They responded in a one-to-one manner to electrical stimuli applied to the visceral nerve, or to impulses generated by a depolarizing current injected into the cell body. EJPs induced by stimuli at higher than 0.5 Hz showed facilitation while those induced at higher than 2 Hz showed summation. Individual EJPs without summation, or a train of EJPs with summation, caused acceleration in the phase of posterograde heartbeat and heart reversal from anterograde heartbeat to posterograde heartbeat. It is likely that the innervation of the anterior region of the dorsal vessel by the motor neurons, through the anterior cardiac nerves is responsible for the control of heartbeat in Lepidoptera, at least in part.     

Cytophotometric assessment of granulosa cell protein and nucleic acid levels during the estrous cycle in rats treated with T-2 toxin

Female Sprague-Dawley rats (160-180g.) with normal estrous cyclicity established by vaginal smears, were injected intraperitoneally with 0.45 mg/kg (low dose) or 0.68 mg/kg (high dose) of T-2 toxin, a trichothecene with potent protein inhibitory abilities. Control animals were injected with only the 100% ethanol vehicle. All animals were decapitated at 8 hours post-exposure, and their ovaries removed and processed for paraffin sectioning. Coomassie, Feulgen, and azure B/DNase staining procedures were used to show granulosa cell protein levels, F-DNA stainability, and basophilia/RNA levels, respectively. Quantification of these parameters was accomplished using scanning-integrating microdensitometry. T-2 toxin treatment groups had granulosa cell protein levels significantly lower than those of the control animals. However, rats exposed to the lower dose of T-2 toxin generally showed a more marked suppression of protein levels than the high dose group, regardless of the stage of the estrous cycle. In addition, rats that received lower doses of T-2 toxin had impaired translation and template activity in response to injury, when compared with the rats in the high dose group. These results are attributed to the lesser degree of circulatory impairment in the low T-2 toxin dosage group, which allows a higher amount of T-2 toxin to interact with the cells.     

Cereals level and source effects on rumen fermentation,colostrum and milk properties,and blood metabolites in periparturient ewes

Optimal type and dietary inclusion rates of cereal grains for periparturient sheep are unknown. The objective was to determine effects of feeding diets with high (H) v. low (L) levels of ground corn grain (CN) v. combined ground wheat and barley grains (WB) on intake, rumen fermentation, colostrum and milk properties, and blood metabolites of periparturient sheep. Twenty Afshari×Merino ewes were used in a completely randomized design study from 24 days prepartum through 21 days postpartum. Ewes were kept indoors in individual boxes and received once daily at 0900 h total mixed rations. Treatments were mixed rations containing either (1) H or (2) L concentrate based on either (1) 100% CN or (2) 50 : 50 ratio of ground wheat : ground barley grains in a 2×2 factorial arrangement. Each treatment group had five ewes including two twin-lamb ewes and three single-lamb ewes. Postpartal dry matter intake (DMI) increased by feeding high CN v. high and low WB, while high v. low CN improved postpartum DMI. The DMI during lambing tended to increase with the high v. low WB. Feeding CN v. WB, and feeding both CN and WB at L v. H level increased fecal pH. Postpartal rumen pH was lower with the high v. low WB (5.7 v. 6.2). Rumen concentrations of propionate were lower and of acetate were higher with L v. H grain levels. Increased dietary grain reduced urine pH for WB (7.24 v. 7.83) but not for CN (7.63 v. 7.52) prepartum. Colostrum properties, postpartal urine pH, lamb weight at birth and 21 days of age, and placental weight and expulsion time were unaffected. Milk yield increased and milk fat yield tended to increase by H v. L grain diets. Plasma glucose was increased by feeding high v. low WB, whereas CN v. WB tended to reduce peripartal plasma non-esterified fatty acids (NEFA) and increased insulin to NEFA ratio. In conclusion, more cereal grains can be included in periparturient sheep diets and CN instead of WB may be fed to periparturient sheep to improve energy status. Findings suggest opportunities to optimize periparturient ewe physiology and performance through feeding certain cereals and avoiding high levels of WB.     

稳定期慢性阻塞性肺疾病患者家庭运动训练现状调查及其影响因素的Logistic回归分析

目的:探讨稳定期慢性阻塞性肺疾病(COPD)患者家庭运动训练现状调查及其影响因素的Logistic回归分析。方法:收集2018年1月～2019年12月期间于本院进行治疗的稳定期COPD患者172例为调查研究对象,根据患者家庭运动训练进行情况将患者分为非运动训练组和运动训练组,对两组患者的一般资料、临床资料等进行统计对比,并采用单因素和多因素Logistic回归分析对影响稳定期COPD患者家庭运动训练进行情况的因素进行分析探讨。结果:在随访调查中,有59例患者进行了家庭运动训练,运动康复训练的普及率为34.30%。经单因素分析,两组患者在性别、年龄、体质指数(BMI)、居住地、婚姻状况、基础疾病、职业对比无显著性差异(P0.05),而两组患者在住院次数、病程、文化程度、照顾情况、肺康复指导对比有显著性差异(P0.05)。经多因素Logistic回归分析显示,COPD患者的住院次数、病程、文化程度、照顾情况、肺康复指导是影响患者进行家庭运动训练的主要因素(P0.05)。结论:我院稳定期COPD患者随访期间家庭运动训练的普及率普遍偏低,且运动方式、强度、频率、规律性等均欠佳。运动训练现状受到患者的住院次数、病程长短、文化程度高低、有无照顾者、有无肺康复指导等因素影响。     

The effect of ”living high–training low” on physical performance in rats

In this research, we hypothesized that, in rats, adaptation to high altitude (2500 m) plus training at low altitude (610 m), ”living high–training low”, improves physical performance at low altitude more than living and training at low altitude (610 m). Rats were divided into four groups: (1) living at low altitude (LL, n=12), (2) living and training at low altitude (LLTL, n=13), (3) living at high altitude (LH, n=12), (4) living at high altitude and training at low altitude (LHTL, n=13). The program for living at high altitude involved raising rats under hypobaric hypoxia (equivalent to 2500 m), and the training program consisted of running on a tread-mill at low altitude. All groups were raised at each altitude and trained to run at 35 m/min for 40 min/day, 6 days/week for 6 weeks. During this program, we measured heart rates both at rest and during exercise, and performed running-time trials. The mean heart rate during exercise was lower in groups with training than in groups without training, and the groups receiving training could run longer than the untrained groups. The LHTL group especially showed the lowest mean heart rate during exercise and the longest running time among all groups. After 6 weeks of the training program, all rats had a catheter implanted into the carotid artery, and the mean systemic arterial pressure was continuously measured during treadmill running. The rate of increase of this pressure as the running intensity increased was lower in groups with training than in groups without training, especially in the LHTL group. Finally, we anesthetized all the rats and extracted both the right and left ventricles, and the triceps surae and liver. Training increased the weight of the left ventricle, triceps surae, and liver. The increase in weight of the left ventricle and triceps surae was higher in the LHTL group than in the LLTL group in particular. It appeared that living high– training low may be an effective strategy to improve performance ability at low altitude. Received: 16 July 1999 / Revised: 24 January 2000 / Accepted: 25 January 2000     

Computer-based malignancy grading of astrocytomas employing a support vector machine classifier, the WHO grading system and the regular hematoxylin-eosin diagnostic staining procedure

OBJECTIVE: To investigate and develop an automated technique for astrocytoma malignancy grading compatible with the clinical routine. STUDY DESIGN: One hundred forty biopsies of astrocytomas were collected from 2 hospitals. The degree of tumor malignancy was defined as low or high according to the World Health Organization grading system. From each biopsy, images were digitized and segmented to isolate nuclei from background tissue. Morphologic and textural nuclear features were quantified to encode tumor malignancy. Each case was represented by a 40-dimensional feature vector. An exhaustive search procedure in feature space was utilized to determine the best feature combination that resulted in the smallest classification error. Low and high grade tumors were discriminated using support vector machines (SVMs). To evaluate the system performance, all available data were split randomly into training and test sets. RESULTS: The best vector combination consisted of 3 textural and 2 morphologic features. Low and high grade cases were discriminated with an accuracy of 90.7% and 88.9%, respectively, using an SVM classifier with polynomial kernel of degree 2. CONCLUSION: The proposed methodology was based on standards that are common in daily clinical practice and might be used in parallel with conventional grading as a second-opinion tool to reduce subjectivity in the classification of astrocytomas.     

Transfer after Working Memory Updating Training

During the past decade, working memory training has attracted much interest. However, the training outcomes have varied between studies and methodological problems have hampered the interpretation of results. The current study examined transfer after working memory updating training by employing an extensive battery of pre-post cognitive measures with a focus on near transfer. Thirty-one healthy Finnish young adults were randomized into either a working memory training group or an active control group. The working memory training group practiced with three working memory tasks, while the control group trained with three commercial computer games with a low working memory load. The participants trained thrice a week for five weeks, with one training session lasting about 45 minutes. Compared to the control group, the working memory training group showed strongest transfer to an n-back task, followed by working memory updating, which in turn was followed by active working memory capacity. Our results support the view that working memory training produces near transfer effects, and that the degree of transfer depends on the cognitive overlap between the training and transfer measures.