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Biomedical subjects

J W Clark

Publications and source records attributed to J W Clark.

At least 37 records · Page 2Linked to original sources
PubMed2001

A few minor suggestions.

We agree with almost all of the analysis in this excellent presentation of the molecular view of avoidance behavior. A few suggestions are made as follows: Referring to response-generated stimuli as ''readily observable" seems not quite right for the kinesthetic components of such stimuli, although their scientific legitimacy is not questioned. Interpreting response-generated stimuli as a form of positive reinforcement is contested, and an alternative interpretation is offered. A possibly simpler interpretation of the Sidman (1962) two-lever experiment is suggested. We question Dinsmoor's (2001) explanation for warning stimuli not being avoided, except for the reference to the weakness of third-order conditioning effects. A final question is raised regarding the nature of the variables that are responsible for the momentary evocation of the avoidance response.

Animals↗
PubMed2001

Phase I and pharmacokinetic study of ecteinascidin 743 administered as a 72-hour continuous intravenous infusion in patients with solid malignancies.

Ecteinascidin 743 (ET-743) is a cytotoxic tetrahydroisoquinoline alkaloid that covalently binds to DNA in the minor groove. The in vitro chemosensitivity of cancer cells to ET-743 is markedly enhanced by prolonging the duration of exposure to the drug. A Phase I study of ET-743 given as a 72-h continuous i.v. infusion every 21 days was performed. Characteristics of the 21 adult patients with refractory solid tumors enrolled in the study were as follows: (a) 12 men; (b) 9 women; (c) median age, 59 years; (d) Eastern Cooperative Oncology Group performance status < or = 1, 20 patients; and (e) two prior regimens of chemotherapy, 7 patients. Dose limiting toxicity (DLT) was defined by typical criteria, except that grade 3 transaminitis did not constitute a DLT. There were no DLTs in the six patients evaluated at the first two dose levels of 600 and 900 microg/m2. Reversible grade 4 transaminitis occurred in two of nine patients after treatment with the first cycle of therapy at the third dose level of 1200 microg/m2. Another patient experienced grade 4 rhabdomyolysis, renal failure requiring hemodialysis, grade 4 neutropenia, and grade 3 thrombocytopenia during the second cycle of therapy with this dose. The maximum tolerated dose was 1200 microg/m2, and an additional six patients were enrolled at an intermediate dose level of 1050 microg/m2. This well-tolerated dose was established as the recommended Phase II dose. The disposition of ET-743 was distinctly biexponential, and a departure from linear pharmacokinetic behavior was evident at the 1200-microg/m2 dose level. Pharmacokinetic parameters determined at 1050 microg/m2 were (mean +/- SD): maximum plasma concentration, 318 +/- 147 pg/ml; initial disposition phase half-life, 9.0 +/- 10.3 min; terminal phase half-life, 69.0 +/- 56.7 h; and total plasma clearance, 28.4 +/- 22.5 liters/h/m2. Prolonged systemic exposure to concentrations of the agent that are cytotoxic in vitro were achieved. Toxicity of the drug is clearly schedule-dependent, because increasing the duration of infusion from 3 or 24 h to 72 h results in decreased myelosuppression and comparable hepatotoxicity. Although there were no objective responses to therapy, clear evidence of antitumor activity was observed in a patient with epithelioid mesothelioma, as confirmed by positron emission tomography studies. A Phase II trial to assess the efficacy of ET-743 against this highly refractory neoplasm has been initiated on the basis of this observation. The therapeutically optimal administration schedule remains to be established, inasmuch as there have been indications of activity against a variety of tumors during Phase I studies when the drug was infused over times ranging from 1 to 72 h. Characterizing the pharmacokinetics of ET-743 during the course of Phase II trials and Phase I combination studies is recommended to assure that this promising new anticancer drug can be used with an acceptable margin of safety.

Adult↗
PubMed2000

A model of the L-type Ca2+ channel in rat ventricular myocytes: ion selectivity and inactivation mechanisms.

1. We have developed a mathematical model of the L-type Ca2+ current, which is based on data from whole-cell voltage clamp experiments on rat ventricular myocytes. Ion substitution methods were employed to investigate the ionic selectivity of the channel. Experiments were configured with Na+, Ca2+ or Ba2+ as the majority current carrier. 2. The amplitude of current through the channel is attenuated in the presence of extracellular Ca2+ or Ba2+. Our model accounts for channel selectivity by using a modified Goldman-Hodgkin-Katz (GHK) configuration that employs voltage-dependent channel binding functions for external divalent ions. Stronger binding functions were used for Ca2+ than for Ba2+. 3. Decay of the ionic current during maintained depolarization was characterized by means of voltage- and Ca2+-dependent inactivation pathways embedded in a five-state dynamic channel model. Particularly, Ca2+ first binds to calmodulin and the Ca2+-calmodulin complex is the mediator of Ca2+ inactivation. Ba2+-dependent inactivation was characterized using the ttau same scheme, but with a decreased binding to calmodulin. 4. A reduced amount of steady-state inactivation, as evidenced by a U-shaped curve at higher depolarization levels (>40 mV) in the presence of [Ca2+]o, was observed in double-pulse protocols used to study channel inactivation. To characterize this phenomenon, a mechanism was incorporated into the model whereby Ca2+ or Ba2+ also inhibits the voltage-dependent inactivation pathway. 5. The five-state dynamic channel model was also used to simulate single channel activity. Calculations of the open probability of the channel model are generally consistent with experimental data. A sixth state can be used to simulate modal activity by way of introducing long silent intervals. 6. Our model has been tested extensively using experimental data from a wide variety of voltage clamp protocols and bathing solution manipulations. It provides: (a) biophysically based explanations of putative mechanisms underlying Ca2+- and voltage-dependent channel inactivation, and (b) close fits to voltage clamp data. We conclude that the model can serve as a predictive tool in generating testable hypotheses for further investigation of this complex ion channel.

Algorithms↗
PubMed2000

Activity of multitargeted antifolate (pemetrexed disodium, LY231514) in patients with advanced colorectal carcinoma: results from a phase II study.

BACKGROUND: The aim of this study was to confirm the activity and assess the safety profile of multitargeted antifolate (MTA) for patients with metastatic colorectal adenocarcinoma. METHODS: Forty-six patients were enrolled in the study, 35 with colon and 11 with rectal carcinoma. Adjuvant therapy was allowed if completed 1 year previously. Patients received MTA 600 mg/m(2) as a 10-minute intravenous infusion once every 21 days. Blood samples were taken every cycle for pharmacokinetic and vitamin metabolite assays. RESULTS: Among 39 patients eligible for efficacy analysis, 1 complete response and 5 partial responses were identified, for an overall response rate of 15.4% (95% confidence interval [CI], 4.1-26. 7%) for all patients. Fifteen patients had stable disease, with 9 living longer than 1 year. The median survival was 16.2 months (95% CI, 10.5-17.0%); 65% of patients were alive at 1 year, and the median time to progression was 4.4 months (range, 3.2-5.7 months). The main toxicities were hematologic, with common toxicity criteria (CTC) Grades 3 or 4 noted as follows: thrombocytopenia (18%), neutropenia (55%), and anemia (18%). Nonhematologic toxicities included Grade 2 or 3 skin reaction (53%), ameliorated by dexamethasone, and Grade 3 transaminases (23%). Dose omissions were not required and 21% of doses were reduced. CONCLUSIONS: MTA has clear activity in patients with colorectal carcinoma, and encouraging survival times were noted. MTA was well tolerated in this patient group, but myelosuppression was frequent. Toxicity may be increased with folate deficiency.

Adult↗
PubMed2000

A phase I study of gemcitabine and docetaxel in patients with metastatic solid tumors.

BACKGROUND: A Phase I study was initiated to determine the maximum tolerated dose of weekly gemcitabine combined with monthly, fixed-dose docetaxel. METHODS: Patients with metastatic solid tumors were treated with docetaxel, 60 mg/m(2), on Day 1 every 28 days. Gemcitabine was administered on Days 1, 8, and 15 and underwent dose adjustment in cohorts of 3-6 patients. At the maximum tolerated dose, 11 additional patients were enrolled. RESULTS: Twenty-six patients received 85 cycles of therapy. At the first dose level, the planned gemcitabine dose on Days 1, 8, and 15 was 800 mg/m(2). Two of the 6 patients treated at this dose level experienced dose-limiting toxicities (DLTs) requiring the reduction of gemcitabine to 600 mg/m(2) per dose and the administration of ciprofloxacin, 500 mg orally twice daily, on Days 8-18. At the second dose level the first 3 patients experienced no DLTs and the dose of gemcitabine was increased to 700 mg/m(2). Two of the 6 patients treated at the 700 mg/m(2) dose level experienced DLTs. Eleven additional patients were enrolled at the recommended Phase II dose of gemcitabine (600 mg/m(2)). At this dose level, Grade 3/4 (according the National Cancer Institute's common toxicity criteria) neutropenia and thrombocytopenia occurred in 12.5% and 2.1% of cycles, respectively. Grade 3 and 4 nonhematologic toxicities were uncommon. Three of seven evaluable patients with pancreatic carcinoma had evidence of significant antineoplastic activity (three partial responses). In addition, two complete responses (one patient with gastric carcinoma and one patient with ovarian carcinoma) and one partial response (patient with hepatocellular carcinoma) were noted in patients with other solid tumors. CONCLUSIONS: The regimen comprised of docetaxel, 60 mg/m(2), on Day 1 and gemcitabine, 600 mg/m(2), on Days 1, 8, and 15 with ciprofloxacin on Days 8-18 every 28 days is safe, well tolerated, and active.

Antimetabolites, Antineoplastic↗
PubMed2000

A closed-loop model of the canine cardiovascular system that includes ventricular interaction.

A closed-loop model of cardiopulmonary circulation has been developed for the study of right-left ventricular interaction under physiologically normal and altered conditions. The core model provides insight into the effects of ventricular interaction and pericardial mechanics on hemodynamics. The complete model contains realistic descriptions of (a) the interacting ventricular free walls and septum, (b) the atria, (c) the pericardium, and (d) the systemic and pulmonary vascular loads. The current analysis extends previous work on ventricular interaction and pericardial influence under isolated heart conditions to loading conditions imposed by a closed-loop model of the circulation. A nonlinear least-squares parameter identification method (Levenberg-Marquardt algorithm) is used, together with parameter sensitivity analysis, to estimate the values of key parameters associated with the ventricular and circulation models. Pressure measurements taken at several anatomical locations in the circulation during open-chest experiments on dogs are used as data in the identification process. The complete circulatory model, including septal and pericardial coupling, serves as a virtual testbed for assessing the global affects of localized mechanical or hemodynamic alterations. Studies of both direct and series ventricular interaction, as well as the effect of the pericardium on cardiac performance, are accomplished with this model. Alterations in model parameter values are used to predict the impact of disease and/or clinical interventions on steady-state hemodynamic performance. Additionally, a software package titled CardioPV has been developed to integrate the complete model with data acquisition tools and a sophisticated graphical user interface. The complete software package enables users to collect experimental data, use the data to estimate model parameters, and view the model outputs in an online setting.

Animals↗
PubMed2000

A phase I clinical and pharmacokinetic study of the dolastatin analogue cemadotin administered as a 5-day continuous intravenous infusion.

PURPOSE: The dolastatins are a class of naturally occurring cytotoxic peptides which function by inhibiting microtubule assembly and tubulin polymerization. Cemadotin is a synthetic analogue of dolastatin 15 with potent antiproliferative and preclinical antitumor activity. This report describes a phase I study to evaluate the administration of cemadotin to adult cancer patients by a 5-day continuous intravenous (CIV) infusion. METHODS: All patients had histologically confirmed refractory solid tumors. The dose was escalated from an initial level of 2.5 mg/m2 (0.5 mg/m2 daily) according to a modified Fibonacci algorithm. A minimum of three patients was evaluated at each dose level until the maximum tolerated dose (MTD) was established. Treatment was repeated every 21 days until patients were removed from the study due to toxicity or disease progression. Drug-related toxicities were evaluated and graded by the U.S. National Cancer Institute's Common Toxicity Criteria. A radioimmunoassay (RIA) that detected both the parent drug and its metabolites with an intact N-terminal region of the molecule was used for pharmacokinetic studies. RESULTS: Twenty heavily pretreated patients received a total of 40 courses of cemadotin over five dose levels ranging from 2.5 to 17.5 mg/m2. Reversible dose-related neutropenia was the principal dose-limiting toxicity and 12.5 mg/m2 was established as the MTD. Nonhematologic toxicities attributed to the drug were moderate, and there was no evidence of the cardiovascular toxicity noted in the prior phase I studies of cemadotin given IV as a 5-min injection or 24-h infusion. There were no objective antitumor responses. Time courses of the cemadotin RIA equivalent concentration in whole blood were defined in 14 patients during the first cycle of therapy. The RIA-detectable species exhibited apparent first-order pharmacokinetics across the entire range of doses. The mean +/- SD of the observed steady-state blood concentration at the 12.5 mg/m2 MTD was 282 +/- 7 nM (n = 3). Blood levels decayed monoexponentially following the end of the infusion, with a mean half-life of 13.2 +/- 4.3 h (n = 14) in all patients. Mean values (n = 14) of the total blood clearance and apparent volume of distribution at steady state were 0.52 +/- 0.09 lh/m2 and 9.9 +/- 3.3 l/m2, respectively. CONCLUSIONS: The cardiotoxic effects of cemadotin were completely avoided by administering it as a 120-h CIV infusion. Thus. cardiovascular toxicity appears to be associated with the magnitude of the peak blood levels of the parent drug or its metabolites, whereas myelotoxicity is related to the duration of time that blood levels exceed a threshold concentration. Nevertheless, the data acquired during the extensive clinical experience with cemadotin requires careful examination to assess whether advancing this compound into disease-oriented efficacy studies is merited.

Adult↗
PubMed2000

Current perspectives on locally advanced pancreatic cancer.

This year, approximately 40% of the 28,300 patients diagnosed with pancreatic carcinoma in the United States will present with locally advanced disease. Radiotherapeutic approaches are often employed, as these patients have unresectable tumors by virtue of local invasion into the retroperitoneal vessels in the absence of clinically detectable metastases. These treatments include external-beam irradiation with and without fluorouracil (5-FU)-based chemotherapy, intraoperative irradiation, and more recently, external-beam irradiation with new systemic agents, such as gemcitabine (Gemzar).

Adenocarcinoma↗
PubMed1999

Theoretical study of inspiratory flow waveforms during mechanical ventilation on pulmonary blood flow and gas exchange.

A lumped two-compartment mathematical model of respiratory mechanics incorporating gas exchange and pulmonary circulation is utilized to analyze the effects of square, descending and ascending inspiratory flow waveforms during mechanical ventilation. The effects on alveolar volume variation, alveolar pressure, airway pressure, gas exchange rate, and expired gas species concentration are evaluated. Advantages in ventilation employing a certain inspiratory flow profile are offset by corresponding reduction in perfusion rates, leading to marginal effects on net gas exchange rates. The descending profile provides better CO2 exchange, whereas the ascending profile is more advantageous for O2 exchange. Regional disparities in airway/lung properties create maldistribution of ventilation and a concomitant inequality in regional alveolar gas composition and gas exchange rates. When minute ventilation is maintained constant, for identical time constant disparities, inequalities in compliance yield pronounced effects on net gas exchange rates at low frequencies, whereas the adverse effects of inequalities in resistance are more pronounced at higher frequencies. Reduction in expiratory air flow (via increased airway resistance) reduces the magnitude of upstroke slope of capnogram and oxigram time courses without significantly affecting end-tidal expired gas compositions, whereas alterations in mechanical factors that result in increased gas exchanges rates yield increases in CO2 and decreases in O2 end-tidal composition values. The model provides a template for assessing the dynamics of cardiopulmonary interactions during mechanical ventilation by combining concurrent descriptions of ventilation, capillary perfusion, and gas exchange.

Computer Simulation↗
PubMed1999

The potential role for prolactin-inducible protein (PIP) as a marker of human breast cancer micrometastasis.

The prolactin-inducible protein (PIP/GCPD15) is believed to originate from a limited set of tissues, including breast and salivary glands, and has been applied as a clinical marker for the diagnosis of metastatic tumours of unknown origin. We have investigated the potential role of PIP mRNA as a marker of human breast cancer metastasis. Using reverse transcription polymerase chain reaction and Southern or dot blot analysis, PIP mRNA was detected in 4/6 breast cell lines, independent of oestrogen receptor (ER) status. In breast primary tumours (n = 97), analysed from histologically characterized sections, PIP mRNA was detected in most cases. Higher PIP mRNA levels correlated with ER+ (P = 0.0004), progesterone receptor positive (PR+) (P = 0.0167), low-grade (P = 0.0195) tumours, and also PIP protein levels assessed by immunohistochemistry (n = 19, P = 0.0319). PIP mRNA expression was also detectable in 11/16 (69%) of axillary node metastases. PIP mRNA expression, however, was also detected in normal breast duct epithelium, skin, salivary gland and peripheral blood leucocyte samples from normal individuals. We conclude that PIP mRNA is frequently expressed in both primary human breast tumours and nodal metastases. However, the presence of PIP expression in skin creates a potential source of contamination in venepuncture samples that should be considered in its application as a marker for breast tumour micrometastases.

Apolipoproteins↗
PubMed1999

Higher-order probabilistic perceptrons as Bayesian inference engines.

An explicit structural connection is established between the Bayes optimal classifier operating on K binary input variables and a corresponding two-layer perceptron having normalized output activities and couplings from input to output units of all orders up to K. With suitable modification of connection weights and biases, such a higher-order probabilistic perceptron should in principle be able to learn the statistics of the classification problem and match the a posteriori probabilities given by Bayes optimal inference. Specific training algorithms are developed that allow this goal to be approximated in a controlled variational sense. An application to the task of discriminating between stable and unstable nuclides in nuclear physics yields network models with predictive performance comparable to the best that has been achieved with conventional multilayer perceptrons containing only pairwise connections.

Journal Article↗
PubMed1999

Parasympathetic modulation of sinoatrial node pacemaker activity in rabbit heart: a unifying model.

We have extended our compartmental model [Am. J. Physiol. 266 (Cell Physiol. 35): C832-C852, 1994] of the single rabbit sinoatrial node (SAN) cell so that it can simulate cellular responses to bath applications of ACh and isoprenaline as well as the effects of neuronally released ACh. The model employs three different types of muscarinic receptors to explain the variety of responses observed in mammalian cardiac pacemaking cells subjected to vagal stimulation. The response of greatest interest is the ACh-sensitive change in cycle length that is not accompanied by a change in action potential duration or repolarization or hyperpolarization of the maximum diastolic potential. In this case, an ACh-sensitive K+ current is not involved. Membrane hyperpolarization occurs in response to much higher levels of vagal stimulation, and this response is also mimicked by the model. Here, an ACh-sensitive K+ current is involved. The well-known phase-resetting response of the SAN cell to single and periodically applied vagal bursts of impulses is also simulated in the presence and absence of the beta-agonist isoprenaline. Finally, the responses of the SAN cell to longer continuous trains of periodic vagal stimulation are simulated, and this can result in the complete cessation of pacemaking. Therefore, this model is 1) applicable over the full range of intensity and pattern of vagal input and 2) can offer biophysically based explanations for many of the phenomena associated with the autonomic control of cardiac pacemaking.

Acetylcholine↗
PubMed1999

Calcium dynamics underlying pacemaker-like and burst firing oscillations in midbrain dopaminergic neurons: a computational study.

A mathematical model of midbrain dopamine neurons has been developed to understand the mechanisms underlying two types of calcium-dependent firing patterns that these cells exhibit in vitro. The first is the regular, pacemaker-like firing exhibited in a slice preparation, and the second is a burst firing pattern sometimes exhibited in the presence of apamin. Because both types of oscillations are blocked by nifedipine, we have focused on the slow calcium dynamics underlying these firing modes. The underlying oscillations in membrane potential are best observed when action potentials are blocked by the application of TTX. This converts the regular single-spike firing mode to a slow oscillatory potential (SOP) and apamin-induced bursting to a slow square-wave oscillation. We hypothesize that the SOP results from the interplay between the L-type calcium current (I(Ca,L)) and the apamin-sensitive calcium-activated potassium current (I(K,Ca,SK)). We further hypothesize that the square-wave oscillation results from the alternating voltage activation and calcium inactivation of I(Ca,L). Our model consists of two components: a Hodgkin-Huxley-type membrane model and a fluid compartment model. A material balance on Ca(2+) is provided in the cytosolic fluid compartment, whereas calcium concentration is considered constant in the extracellular compartment. Model parameters were determined using both voltage-clamp and calcium-imaging data from the literature. In addition to modeling the SOP and square-wave oscillations in dopaminergic neurons, the model provides reasonable mimicry of the experimentally observed response of SOPs to TEA application and elongation of the plateau duration of the square-wave oscillations in response to calcium chelation.

Animals↗
PubMed1999

Computational model of the serotonergic modulation of sensory neurons in Aplysia.

Serotonergic modulation of the sensory neurons that mediate the gill- and tail-withdrawal reflexes of Aplysia is a useful model system for studies of neuronal plasticity that contributes to learning and memory. The effects of serotonin (5-HT) are mediated, in part, via two protein kinases (protein kinase A, PKA, and protein kinase C, PKC), which in turn, modulate at least four membrane currents, including a S ("serotonin-sensitive") K(+) current (I(K, S)), a steeply voltage-dependent K(+) current (I(K-V)), a slow component of the Ca(2+)-activated K(+) current (I(K,Ca-S)), and a L-type Ca(2+) current (I(Ca-L)). The present study investigated how the modulation of these currents altered the spike duration and excitability of sensory neurons and examined the relative contributions of PKA- and PKC-mediated effects to the actions of 5-HT. A Hodgkin-Huxley type model was developed that described the ionic conductances in the somata of sensory neurons. The descriptions of these currents and their modulation were based largely on voltage-clamp data from sensory neurons. Simulations were preformed with the program SNNAP (Simulator for Neural Networks and Action Potentials). The model was sufficient to replicate empirical data that describes the membrane currents, action potential waveform and excitability as well as their modulation by application of 5-HT, increased levels of adenosine cyclic monophosphate or application of active phorbol esters. In the model, modulation of I(K-V) by PKC played a dominate role in 5-HT-induced spike broadening, whereas the concurrent modulation of I(K,S) and I(K,Ca-S) by PKA primarily accounted for 5-HT-induced increases in excitability. Finally, simulations indicated that a PKC-induced increase in excitability resulted from decreases of I(K,S) and I(K,Ca-S), which was likely the indirect result of cross-talk between the PKC and PKA systems. The results provide several predictions that warrant additional experimental investigation and illustrate the importance of considering indirect as well as direct effects of modulatory agents on the modulation of membrane currents.

Action Potentials↗
PubMed1998

Airway mechanics, gas exchange, and blood flow in a nonlinear model of the normal human lung.

A model integrating airway/lung mechanics, pulmonary blood flow, and gas exchange for a normal human subject executing the forced vital capacity (FVC) maneuver is presented. It requires as input the intrapleural pressure measured during the maneuver. Selected model-generated output variables are compared against measured data (flow at the mouth, change in lung volume, and expired O2 and CO2 concentrations at the mouth). A nonlinear parameter-estimation algorithm is employed to vary selected sensitive model parameters to obtain reasonable least squares fits to the data. This study indicates that 1) all three components of the respiratory model are necessary to characterize the FVC maneuver; 2) changes in pulmonary blood flow rate are associated with changes in alveolar and intrapleural pressures and affect gas exchange and the time course of expired gas concentrations; and 3) a collapsible midairway segment must be included to match airflow during a forced expiration. Model simulations suggest that the resistances to airflow offered by the collapsible segment and the small airways are significant throughout forced expiration; their combined effect is needed to adequately match the inspiratory and expiratory flow-volume loops. Despite the limitations of this lumped single-compartment model, a remarkable agreement with airflow and expired gas concentration measurements is obtained for normal subjects. Furthermore, the model provides insight into the important dynamic interactions between ventilation and perfusion during the FVC maneuver.

Adult↗
PubMed1998

Feedback, test anxiety and performance in a college course.

The effects of three forms of test feedback and text anxiety on test performance were examined within the context of a self-paced, criterion-based course in educational psychology. 73 undergraduate students completed seven units of work and were evaluated by computer-administered unit tests. Students were randomly assigned to one of three test feedback forms: (1) item-by-item knowledge of responses, (2) answer-until-correct, and (3) delayed feedback. Students received their assigned feedback during the first two units, after which they were allowed to choose. Test anxiety was measured prior to testing on Sarason's Test Anxiety Scale and during testing on an item administered by the computer program. Students who reported high test anxiety on the Test Anxiety Scale experienced more anxiety during testing than students reporting low test anxiety. Anxiety during testing was not related to type of feedback, and the two variables were not related to course performance on the second unit. Data collected at the conclusion of the semester indicated that students who reported higher test anxiety required more attempts to pass unit tests than those reporting lower test anxiety. Given a choice, students preferred answer-until-correct feedback. This preference was not related to Test Anxiety Scale scores. Anxiety during testing was not related to being allowed to choose forms of feedback.

Achievement↗
PubMed1998

Initial evidence for reliability and validity of a brief screening inventory for personality traits.

A short inventory was developed to screen for avoidant, borderline, and dependent personality disorders in clinic settings. The Personality Concerns Inventory items, adapted from the DSM-IV criteria for these disorders, along with the Millon-III was administered to 86 undergraduate students. Reliability estimates for the three scales were .87, .81, and .80. Scores on the three scales also correlated .49 to .57 with scores on the Avoidant, Borderline, and Dependent scales of the Millon-III.

Adolescent↗