Synergistic approach to cancer therapy: exploiting interactions between anti-estrogens, retinoids, monoterpenes and tyrosine kinase inhibitors

Non-responsiveness and toxicity are large problems encountered during cancer treatment. Utilization of compounds that synergize should increase treatment efficacy while avoiding problems of toxicity. This review explores interactions between classes of compounds, including anti-estrogens, retinoids, monoterpenes and tyrosine kinase inhibitors, that are effective independent, and how their synergistic interaction could be exploited in cancer treatment. The effects of these compounds on insulin-like growth factors (IGF) and transforming-growth factor-beta (TGF-beta) will also be examined.

Physiological basis for use of insulin-like growth factors in reproductive applications: a review

The insulin-like growth factors (IGF-I and -II) are ubiquitously expressed factors that regulate cell growth, differentiation and maintenance of differentiated cell function. All aspects of male and female reproduction are influenced by the IGF system. This review will examine the IGF system as it pertains to reproductive physiology and applications.

Actions and interactions of the IGF system in Alzheimer's disease: review and hypotheses

Insulin-like growth factors (IGF) are pleiotrophic polypeptides affecting all aspects of growth and development. The IGF system, including ligands, receptors, binding proteins and proteases is also involved in pathophysiological conditions, such as cancer and degenerative conditions. In this review, the actions and interactions of the IGF system as it relates to Alzheimer's disease will be investigated.

Adverse drug events in elderly patients receiving home health services following hospital discharge

OBJECTIVE

To assess incidence, healthcare consequences, and identify risk factors for adverse drug events (ADEs) in elderly patients receiving home health services during the month following hospital discharge.

METHOD

This was a prospective cohort study of three home health agencies in Madison, Wisconsin, and its surrounding area. The sample consisted of 256 participants aged > or =65 years who were hospitalized for medical illness, received home nursing after discharge, and completed the one-month interview. The main outcome measure was self-reported ADEs (possible, probable, or definite) during the month following hospital discharge.

RESULTS

Incidence of ADEs was 20%. Fifty-two participants (20.3%) reported 64 ADEs: 23 possible, 37 probable, and four definite. The most common ADEs involved the gastrointestinal tract (31.3%) and the central nervous system (31.3%). Of 53 ADEs reported to providers, 59% of the drugs were discontinued or altered. One ADE resulted in hospitalization. In logistic regression, female gender (OR = 2.26; 95% CI 1.06 to 4.77) and the interaction between number of new medications and cognition were significantly associated with ADEs. The risk of an event increased with the number of new medications at discharge; however, risk was elevated primarily for participants with lower cognition.

CONCLUSIONS

ADEs were common during the month following hospital discharge, were more frequent in women, and often resulted in medication changes. Individuals at particular risk were those with lower cognition who were discharged with several new medications.

The insulin-like growth factor (IGF) system and gonadotropin regulation: actions and interactions

Insulin-like growth factors (IGF) are polypeptides that regulate growth, differentiation and survival in a multitude of cells and tissues. The IGF system consists of ligands, receptors, binding proteins and binding protein proteases. The influence of the IGF system on reproductive parameters, specifically gonadotropin release and interactions between the IGF system and other effectors of gonadotropin release will be examined in this review.

Drug-induced cognition disorders in the elderly: incidence, prevention and management

The aetiology of cognitive impairment is multifactorial; however, drugs are an important cause of delirium and dementia. Several factors may increase the risk of drug-induced cognition disorders in the elderly including imbalances in neurotransmitters (e.g. acetylcholine), age-related alterations in pharmacokinetics and pharmacodynamics, and high levels of medication use. Nearly any drug can cause cognitive impairment in susceptible individuals; however, certain classes are more commonly implicated. Benzodiazepines, opioids, anticholinergics, and tricyclic antidepressants are probably the worst offenders. Older antihypertensive agents (reserpine, clonidine) have negative effects on cognition; however, large clinical trials in the elderly indicate that commonly used agents [e.g. thiazide diuretics, calcium antagonists (amiodipine, diltiazem), ACE inhibitors (captopril, enalapril) and beta-blockers (atenolol)] have minimal effects on cognition. Newer antidepressants such as selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs) and reversible inhibitors of monoamine oxidase A have not been shown to have negative effects on cognition. Although some drugs have shown low risk for causing cognition disorders in research studies, risk may be increased in frail older adults taking several medications and each case should be reviewed carefully. Identification of drug-induced cognitive impairment is crucial to early detection and resolution of symptoms. Preventive strategies directed at avoiding high risk medications when possible, appropriately adjusting doses based on age-related changes and close follow-up may prevent these conditions.

Computer-assisted sperm motion analysis of bovine sperm treated with insulin-like growth factor I and II: implications as motility regulators and chemokinetic factors

The effects of insulin-like growth factors (IGFs) I and II on motility of bovine sperm were examined using a computer-assisted sperm motion analyzer (CASA). The following kinematic parameters were examined: percentage of rapidly moving cells, straight-line velocity , curvilinear velocity, average path velocity, amplitude of lateral head displacement, and beat cross frequency. Sperm were treated with IGF-I (100 ng/mL) or IGF-II (250 ng/mL) and compared to sperm in modified Tyrodes' medium only (control) at 90, 180, and 360 min using CASA. Insulin-like growth factor I and II increased the percentage of rapidly moving cells, straight-line velocity, curvilinear velocity, average path velocity, amplitude of lateral head displacement, and beat cross frequency compared to the control treatment. These results indicate that IGFs may be involved in initiation and maintenance of bovine sperm motility.

Identification of insulin-like growth factor I in bovine seminal plasma and its receptor on spermatozoa: influence on sperm motility

Insulin-like growth factor I (IGF-I) has been identified in human seminal plasma. This study was conducted to determine whether IGF-I is present in bovine seminal plasma, whether sperm cells express the IGF-I receptor (IGF-IR), and whether IGF-I affects sperm motility. Semen samples were collected from bulls by electroejaculation and maintained at 37 degrees C, and motility of sperm was assessed. After centrifugation to separate sperm cells from seminal plasma, the seminal plasma was submitted to a validated heterologous RIA for IGF-I. Significant concentrations of IGF-I (116.29 +/- 40.83 ng/ml expressed as mean +/- SD) were measured in bovine seminal plasma. Sperm cells were washed with buffer and subjected to either radioreceptor assay (RRA) or immunocytochemistry (IC). RRA revealed a single high affinity for the IGF-IR with a Kd of 0.83 nM as determined by the computer program LIGAND. IC, using three monoclonal antibodies, localized the IGF-IR to the acrosomal region of the sperm. Computer-assisted sperm-motion analysis was used to determine the effects of IGF-I and IGF-II on bovine sperm motility parameters. Both IGF-I and IGF-II increased sperm motility and straight-line velocity (p < 0.05) relative to the control. The presence of IGF-IR on sperm, the presence of IGF-I in semen, and the ability of IGF-I to stimulate sperm motility provide evidence that the IGF system may be involved in the fertilization process in the bovine species.

Molecular cloning of a novel chemokine receptor-like gene from early stage chick embryos

Proliferation, differentiation and regulated trafficking of cells are the hallmarks of development and embryogenesis. This led us to speculate a role for chemokines and their receptors in this process. Here, we report the molecular cloning of AvCRL1, a novel member of the G-protein coupled receptor family from early stage 3 days old chick embryos. While the function and ligand for this receptor remain unknown, its sequence and gene structure indicates that it is most related to the family of chemokine receptors, with highest homology to the virally induced human BLR-1 and the CXCR3 or gammaIP-10/Mig-1 receptors.

Adverse drug events in hospitalized elderly

BACKGROUND

The study objectives were (a) to describe the occurrence, types, and preventability of adverse drug events (ADEs) in hospitalized patients 70 years of age and older; (b) to examine the association between potential risk factors and ADEs; and (c) to examine the relationship of an ADE occurrence and hospital length of stay (LOS) and functional decline.

METHOD

Consecutive general medical admissions (n = 157) of community-dwelling persons were prospectively monitored daily for ADE occurrence. Admission assessment included demographic factors, cognition, preadmission medication use, and functional status. Discharge assessment included functional status. LOS, discharge diagnoses, and medication use during the hospitalization.

RESULTS

Twenty-three patients (14.6%) experienced 28 probable ADEs, of which 54.2% (13/24) were judged to be potentially preventable. Patients experiencing an ADE had a significantly lower mean Mini-Mental State Examination score (23.6 +/- 4.3 vs 25.5 +/- 3.6, p = .039) and were prescribed significantly more new inpatient medications (4.0 +/- 2.3 vs 2.6 +/- 1.7, p = .01) compared to non-ADE patients. Age, gender, functional status prior to admission, percent with more than four active diagnoses, or number of preadmission medications were not associated with ADE status. Upon discharge, 50.0% of ADE patients experienced a decline in one or more activities of daily living (ADLs), compared with 24.1% of non-ADE patients (p = .017). ADE patients had a longer LOS (8.7 +/- 4.9 vs 6.6 +/- 3.0 days, p = .022) compared to non-ADE patients.

CONCLUSIONS

ADEs were associated with number of new inpatient medications and admission cognitive status, but not demographic, disease, or physical function variables. Patients experiencing an ADE were more likely to experience a longer LOS and to decline in ADL function. ADEs may be one factor contributing to functional decline during hospitalization. Future research in this area should include larger samples and multivariable analyses controlling for potential confounders.

Donepezil use in Alzheimer disease

OBJECTIVE

To review the pharmacology, pharmacokinetics, clinical efficacy, adverse effects, drug-drug interactions, and the therapeutic issues concerning the use of donepezil in patients with Alzheimer disease.

DATA SOURCES

Published articles and abstracts in English were identified by MEDLINE (January 1985-July 1997) searches using the search terms donepezil, E2020, treatment of Alzheimer's disease, and cholinesterase inhibitors. Additional articles were identified from the bibliographies of the retrieved articles. Data were also obtained from approved product labeling.

DATA EXTRACTION

The literature was assessed for adequate description of patients, methodology, and outcomes.

DATA SYNTHESIS

Donepezil is a cholinesterase inhibitor that is selective and specific for acetylcholinesterase. It is metabolized by hepatic isoenzymes CYP2D6 and CYP3A4 and undergoes glucuronidation. Information about drug interactions is limited, but a potential for drug-drug interactions does exist, given the route of elimination. Donepezil has a relative bioavailability of 100% following oral administration and is not affected by the presence of food. In 15- and 30-week trials, donepezil was effective in patients with mild-to-moderate Alzheimer disease as shown by improvements on standard assessment instruments (i.e., the Alzheimer's Disease Assessment Scale-Cognitive Subscale, the Clinical Interview-Based Impression of Change with Caregiver Input). Adverse effects were comparable with those of placebo, and monitoring of liver function tests is not required.

CONCLUSIONS

Donepezil is an effective symptomatic treatment for some patients with mild-to-moderate Alzheimer disease. Although no comparative trials have been reported, donepezil appears to be a safe alternative for tacrine, given its convenient once-daily dosing, minimal adverse effects, and lower total cost.

Effect of a single dose of diazepam on balance measures in older people

OBJECTIVE

This study examines the effect of a single dose of diazepam on a spectrum of balance measures in healthy older subjects. The measures include static (postural sway), dynamic (anterior tibialis muscle activation latency), and a complex self-initiated task of balance (functional reach) in addition to neuropsychological tests of attention.

DESIGN

A double-blind, two-period, cross-over trial.

SETTING

The community surrounding a university hospital.

PARTICIPANTS

Community-dwelling, nonsmoking volunteers 65 years of age and older.

MEASUREMENTS

Measures included response to unexpected perturbation (platform/EMG muscle latency), self-initiated perturbation (functional reach), and a static measure of balance (postural sway). Neurocognitive tests (digital symbol substitution test, card sorting) were included to document the cognitive effect.

RESULTS

Twelve nonsmoking healthy subjects (average age = 70.4 years (66-76 years)) participated. The anterior tibalis muscle latency increased in response to a sudden perturbation with diazepam compared with placebo (TA latency 149 ms vs 142 ms, P < .001). Neurocognitive tests were adversely affected for 90 minutes after diazepam administration compared with placebo (P < .05). Other measures did not demonstrate significant effect of diazepam.

CONCLUSIONS

This is among the first reports showing that benzodiazepines affect neuromuscular processing related to balance control. Increased muscle latency to sudden perturbations may represent an effect of diazepam upon the oligosynaptic spinal reflex distinct from the sedation. Surface electromyography may be a valuable noninvasive tool for future studies of drug effect on balance and falls risk among older people.

Depression, cognitive impairment, and understanding of medication directions in hospitalized elderly patients

PURPOSE

The objectives of this study were 1) to assess understanding of medication directions of drug therapy in a group of hospitalized elderly who were not receiving assistance with medication administration; and 2) to determine whether depression, cognitive impairment, age, and other characteristics are associated with patient understanding of medication directions.

METHODS

The sample consisted of 117 hospitalized elderly patients aged 70 years and older who were taking two or more medications prior to hospitalization and reported medication self-administration. Data collection included demographic characteristics, mood, cognition, and pre-admission medication use and knowledge.

RESULTS

Thirteen (11%) patients did not understand directions for two or more pre-admission medications. Being 80 years or older was associated with not understanding medication directions (OR = 6.2, p = .017). There was a trend for depressive symptoms to be associated with not understanding medication directions, however, this was not significant (OR = 3.9, p = .058).

CONCLUSIONS

Although all individuals should be assessed for comprehension of their medication regimens, those over 80 years of age with depressive symptoms deserve increased attention. Alternative strategies may need to be developed to improve medication knowledge in the older, depressed hospitalized patient.

Predictors of nutritional supplement use by the elderly

We conducted a population survey to describe patterns and determine predictors of the use of nutritional supplements and single-ingredient vitamins and minerals among elderly living in five adjacent urban and rural counties in the Piedmont area of North Carolina. The stratified random sample consisted of 3939 black and white participants age 65 or older from the Duke Established Populations for Epidemiologic Studies of the Elderly. The use of nutritional supplements within the previous 2 weeks was determined during an in-home interview. Multivariate analyses, using weighted data adjusted for sampling design, were conducted to assess the association between nutritional supplement use and predisposing, need, and enabling factors. Nutritional supplement use was reported by 26.2% of participants and was more likely for those who were white women, were high school educated, were underweight, took prescription drugs, had five or more health visits in the previous year, and had supplemental health insurance. It was less likely for those with poor self-rated health. The majority (71.5%) of nutritional supplement users took at least one single-ingredient supplement. Use of such products was more likely in those who were white, born and raised in an urban area, and high school educated, and was less likely in those with impaired functional status. Nutritional supplement use is prevalent in community-dwelling elderly and is more commonly associated with demographic factors and access to health care than with need factors.

Characteristics predicting incorrect metered-dose inhaler technique in older subjects

OBJECTIVE

To determine whether cognitive status, hand strength, and demographic variables are predictive of correct use of metered-dose inhalers by older subjects.

METHODS

Clinic patients (n = 29) and healthy volunteers (n = 42) older than 50 years with no previous or limited metered-dose inhaler use were enrolled. After cognitive (Mini-Mental State Examination) and hand strength assessments, subjects received extensive instruction in proper metered-dose inhaler technique. Technique was independently assessed by two evaluators immediately after instruction and 1 week later. Correct technique was defined as (1) activating the canister in the first half of inhalation, (2) continuing to inhale slowly and deeply, and (3) holding breath at full inspiration (5 seconds). Data for the two subject groups were pooled for analyses.

RESULTS

The mean age of the subjects was 69.7 years. Forty subjects (56%) demonstrated correct metered-dose inhaler technique at 1 week. Logistic regression showed that hand strength measurement (odds ratio, 0.68; 95% confidence interval, 0.55 to 0.84), Mini-Mental State Examination score less than 24 (odds ratio, 3.66; 95% confidence interval, 1.07 to 12.4), and male gender (odds ratio, 5.01; 95% confidence interval, 1.07 to 23.5) were significant predictors of incorrect inhaler use. Correct use of the metered-dose inhaler was unrelated to age, education, or subject status.

CONCLUSIONS

Clinicians should consider cognitive status and hand strength when metered-dose inhaler therapy is initiated for an older adult. Patients with cognitive impairment and hand strength deficits may require more extensive training, frequent follow-up, or alternative dosage forms.

Management of older adults with hypercholesterolaemia

Although the strength of total cholesterol levels as a relative risk factor for coronary heart disease (CHD) declines with age, the prevalence of CHD increases dramatically with age. Data from cholesterol treatment trials, although sparse in older adults, suggest that dyslipidaemia treatment has the potential to prevent CHD. In particular, dyslipidaemia treatment appears to be most beneficial in older adults with a history of CHD or who have several other CHD risk factors. Dyslipidaemia screening should be selective in the elderly, reserved for those whose health status would be amenable to nutritional or pharmacological therapy, and in whom several CHD risk factors or a history of CHD are present. Since high density lipoprotein cholesterol (HDL) levels retain their inverse association CHD in old age, cholesterol subfractions should be measured in persons being screened in order to adequately assess the severity of dyslipidaemia. Treatment decisions should be guided by the patient's dyslipidaemic class, which is determined by the cholesterol subfractions and serum triglycerides (TG). As in younger persons, nutritional therapy remains the first step in dyslipidaemia management in high risk, nondebilitated older adults. An array of cholesterol modifying medications are available which vary widely in treatment effects, adverse effects and cost. Extra care needs to be taken in prescribing these agents in older adults because of greater potential for adverse effects and interactions with other medications. The cost-effectiveness of pharmacological treatment decreases with age and increases with the severity of dyslipidaemia, a history of CHD, or the presence of multiple CHD risk factors. When comparing elderly to middle-aged adults, the relative cost-effectiveness of different cholesterol-lowering medications may be altered due to age-related changes in therapeutic efficacy and adverse effects.

Assessment of interrater and intrarater reliability in the evaluation of metered dose inhaler technique

STUDY OBJECTIVE

To determine if a training session using videotaped metered dose inhaler (MDI) performances can result in high interrater and intrarater reliability of five evaluators assessing MDI technique.

DESIGN

Five evaluators (three pharmacists, two pulmonary fellows) were trained to evaluate MDI technique during a 2-h training session. The training session consisted of verbal instruction and practical experience in evaluating MDI technique using video-taped MDI performances of six nonstudy subjects. After the training session, the evaluators independently observed the same videotaped MDI demonstrations of 14 subjects on two occasions separated by a 7- to 10-day interval. Interrater and intrarater reliability was determined for individual steps by calculating percent agreement and intraclass correlation (ICC) coefficient.

RESULTS

Interrater. The interrater reliability for individual steps ranged from 29 to 86 percent (ICC coefficient = 0.13 to 0.81). Steps in which evaluators were in agreement for less than 9 of the 14 subjects were shaking the inhaler before inhalation, exhaling, continuing to inhale slowly, and adequate breath hold. Intrarater: The overall percent agreement by step ranged from 74 to 97 percent. Exhaling to functional residual volume (76 percent) and continuing to inhale slowly and deeply (74 percent) had the lowest overall agreement between the first and second observation day. The consistency of evaluating a step between the two observation days varied considerably depending on the step and evaluator.

CONCLUSIONS

High interrater and intrarater reliability in MDI evaluation is difficult to obtain. Clinicians and researchers involved in MDI evaluation and education should be trained to achieve consistency. A single training session using videotaped MDI demonstrations was not adequate in achieving consistency among evaluators. To improve accuracy of research results, researchers should include at least two evaluators to assess MDI technique or take other measures to show and report reliability.

Measured versus estimated creatinine clearance in a high-functioning elderly sample: MacArthur Foundation Study of Successful Aging

OBJECTIVE

To assess the validity of several equations for estimating creatinine clearance in a large sample of high-functioning, community-dwelling elderly.

DESIGN

Serum and 12-hour urine samples were collected and assayed for creatinine using the Jaffe total chromagen method. Fifteen clearance-estimating equations were evaluated for bias, accuracy, correlation with measured clearance values, and frequency of erroneous placement into renal function categories. Stepwise regression modeling and reliability testing were performed on a split sample to construct and assess a novel creatinine-clearance-estimating equation.

SETTING

New Haven, Connecticut, East Boston, Massachusetts, and a five-county region in and around Durham, North Carolina.

PARTICIPANTS

A subsample of community-dwelling men and women (age range 70-79 years) from the Established Populations for Epidemiological Studies of the Elderly was screened for physical and cognitive functioning and placed into high-, medium-, and low-functioning groups (n = 1354). High-functioning respondents who provided blood and complete urine samples (n = 762) were included in the present study.

RESULTS

In general, estimated creatinine clearance was more closely correlated to measured values in males than in females. Most equations underestimated creatinine clearance, with average bias ranging from -33.1 mL/min to +19.6 mL/min. Predictive accuracy ranged from 18.2 mL/min to 38.0 mL/min. Equations were variable in their erroneous placement of individuals into renal function categories. Regression modeling yielded an equation which contained novel components but failed to provide better estimates of creatinine clearance than those already available.

CONCLUSIONS

The equations evaluated here provide unacceptable predictions of creatinine clearance in normally aging individuals. We advocate the use of serum drug concentration measurements when available and encourage investigation into timed urine collections of short duration as alternatives to clearance-estimating equations in the elderly.

Secretory patterns of growth hormone and insulin-like growth factor-I during peripubertal period in intact and castrate male cattle

Fifteen Angus bulls and 15 Angus steers 9 months of age and 275 kg of body weight were bled at 20-min intervals over a 6-hr period and serum GH and IGF-I concentrations were measured by RIA. There were no differences between bulls and steers in the mean GH concentration, pulse frequency and amplitude when analyzed by the computer program PULSAR. Mean IGF-I concentration was not different between the two sex phenotypes, nor was there a significant correlation between the integrated IGF-I and GH concentrations. Subsequently, five bulls and five steers were selected from the 30 animals, full-fed a diet for growth in individual pens for 3 months and bled at 15-min intervals over a 24-hr period. Bulls tended to show a greater weight gain and feed conversion efficiency (P less than .10) than steers during the 3-month period. Serum GH concentrations had a pulsatile pattern in all animals with no apparent diurnal rhythm during the 24-hr bleeding. Although mean GH concentration was not different between the two sex phenotypes, bulls tended to have lower baseline levels (P less than .10) and greater peak amplitudes than steers. Serum IGF-I concentrations fluctuated within a two-fold concentration range, with no obvious pulsatility similar to that of GH. Mean IGF-I concentrations of each of the 10 animals were correlated with mean peak GH amplitudes (r = .79), but not with mean GH. These results suggest that gonadal hormone(s) modulates the GH secretory pattern and increases IGF-I secretion which may be related to the greater growth rate of bulls compared with steers.

Effect of holding time and temperature of bovine whole blood on concentration of progesterone, estradiol-17β and estrone in plasma and serum samples

Bovine jugular venous blood was collected, with and without heparin, and aliquoted into 140 12-ml tubes. Four subsamples (two heparinized and two coagulated) were centrifuged immediately (time zero) and plasma or serum was aspirated and stored at -20 degrees C. One-half of the remaining subsamples were stored at 4 degrees C and the other one-half at 25 degrees C (room temperature). At 1-h intervals (0 to 24 h), 6-h intervals (24 to 72 h) and at 96 and 120 h, four subsamples (heparinized and coagulated at both 4 degrees C and 25 degrees C) were centrifuged, plasma or serum was aspirated and stored at -20 degrees C. Whole blood incubation for 1 h at 25 degrees C reduced mean plasma and serum progesterone (P(4)) concentration (P<0.05). Similarly, whole blood incubation at 4 degrees C for 2 and 3 h, respectively, reduced mean plasma and serum P(4) concentration (P<0.05). No difference was found in mean P(4) concentration between plasma and serum samples harvested from whole blood incubated at 4 degrees C or 25 degrees C. Concentration of estradiol-17beta (E(2)) and estrone (E(1)) fluctuated over time, irrespective of holding temperature. There was a blood type, heparinized or coagulated, by time interaction (P<0.01) for both E(2) and E(1) concentrations It was concluded that incubation time and temperature between collection and centrifugation of bovine blood samples influenced the assayable P(4) concentration in both plasma and serum. In contrast, incubation temperature had no effect on assayable E(2) and E(1) concentrations, but assayable E(2) and E(1) over time were differentially affected, depending on whether plasma or serum was assayed.

Prenatal ethanol exposure fails to affect stimulus reactivity in the rat

Three groups of male Long-Evans rats, that were the offspring of dams maintained throughout pregnancy on a liquid diet in which 35% of the calories were derived from ethanol, pair fed an isocaloric liquid diet that had maltose-dextrin substituted for the ethanol, or maintained on lab chow and water were used as subjects. All subjects were nursed by foster mothers maintained on lab chow and water throughout pregnancy and lactation. The groups were not found to differ on open field activity or number of approaches to four stimulus objects in an open field at 26-30 days of age, on spontaneous alternation at 50-55 days of age or on response to a novel alley at 55 days of age. It was concluded that in the rat, prenatal ethanol exposure does not result in demonstrable changes in responsivity to stimuli in rats tested after 26 days of age.

Hyperresponsiveness to methylphenidate in rats following prenatal ethanol exposure

Rats exposed in utero to ethanol are hyperresponsive to methylphenidate when tested as neonates or adults. Long-Evans rats were maintained on liquid diets containing either ethanol or maltose-dextrin (35% of total calories) or on lab chow and water throughout pregnancy. Male offspring, who were raised by foster mothers maintained on lab chow and water throughout pregnancy and lactation, were used in two experiments to examine the effects of methylphenidate on activity. In Experiment 1, a time-sampling procedure revealed that methylphenidate (0, 1, 2 & 4 mg/kg) increases the frequency of ambulation in young (26-38 day old) ethanol-treated offspring more than in control offspring. In Experiment 2, an open-field procedure revealed that methylphenidate (0, 2, 4, 6 & 8 mg/kg) produces greater increases in number of squares covered and the total duration of ambulation during 5-min tests in adult (100-184 day old) offspring treated prenatally with ethanol than in control offspring. Both studies revealed that the hyperactivation effect increases with increased doses of methylphenidate.