Effect of chloroquine on the bioavailability of ciprofloxacin in humans

Chloroquine, a front-line drug in the treatment of malaria, has developed widespread resistance, especially to the Plasmodium falciparum strains. Ciprofloxacin is a second-generation quinolone used as a broad-spectrum fluoroquinolone antibacterial agent. The possibility of using ciprofloxacin as an antimalarial, especially in chloroquine-resistant strains, is very promising. They concluded from in vitro studies however that the anti-malarial effect occur at high dose level of ciprofloxacin to achieve the required serum concentrations. Studies have shown that there is little interstrain variability in the in vitro susceptibility of P. falciparum to fluoroquinolones. There is also no cross-resistance between them. Another study stated that 50% inhibition of parasite growth in vitro required 6.6 microg/mL after a high dose of ciprofloxacin was used. They thus concluded that ciprofloxacin should not be used alone. There is need for in vivo studies to ascertain the achievable serum concentration of ciprofloxacin when given alone and when given in combination with chloroquine. The serum concentration of ciprofloxacin was studied when ciprofloxacin was given alone and in combination with chloroquine in humans. Five healthy male volunteers aged (19-31) years who were not taking any of the prescribed medications and had no sensitivity to either ciprofloxacin or chloroquine, each received 500 mg ciprofloxacin orally with 250 mL of water, and after a 2-week wash-out period, 500 mg ciprofloxacin plus 600 mg of chloroquine was administered orally with 250 mL of water after informed consent. A blood sample (2.5 mL) was collected just before taking the drug at 8:00 AM representing 0 hours and continued afterward at 1, 2, 4, 8, 12, and 24 hours the following day. Serum samples were stored at -20 degrees C until analyzed. The minimal inhibitory concentrations (MIC) by diffusion through agar technique was used for the assay of serum ciprofloxacin. The following bioavailability parameters: Cmax, tmax, and AUC 0-24, AUC 0-infinity were calculated. The peak serum concentration Cmax of ciprofloxacin was 3.42 +/- 0.32 microg/mL, which dropped to 2.8 +/- 0.18 microg/mL when chloroquine was taken together with ciprofloxacin. These values were less than the in vitro 12.5 microg/mL concentrations required to inhibit P. falciparum. Though the effect of parasitemia was not ascertained, the in vivo use of ciprofloxacin alone or in combination is doubtful because increasing the dose that will reach the in vitro level will lead to toxicity in vivo.

Synthesis of 8-geranyloxypsoralen analogues and their evaluation as inhibitors of CYP3A4

Furanocoumarins have been shown to inhibit CYP3A4 in vitro with varying degrees of potency. In this study, we report the effects of a series of novel furanocoumarins based on the naturally occurring derivative 8-geranylepoxypsoralen which has been shown to be a more potent inhibitor of CYP3A4 than its 5-position-substituted counterpart bergamottin. Compounds were designed, synthesised and tested for their ability to inhibit CYP3A4 activity in human liver microsomes using testosterone as the marker substrate. Both the saturated and unsaturated phenolic furanocoumarin derivatives were found to be inactive. However, the 8-alkyloxy-furanocoumarin analogues were shown to inhibit CYP3A4 activity in a dose dependent manner, with IC(50) values ranging from 0.78+/-0.11 to 3.93+/-0.53 microM. The reduced furan derivative dihydro-8-geranyloxypsoralen showed a 4-fold decrease in inhibitory potency, suggesting that the furan moiety plays a role in the interaction between these compounds and CYP3A4.

Design, synthesis and evaluation of furanocoumarin monomers as inhibitors of CYP3A4

A number of furanocoumarins isolated from grapefruit juice have been found to inhibit CYP3A4 activity in vitro. In this study, we have designed and synthesised a range of analogues based on bergamottin to investigate the relationship between chemical structure and inhibition of CYP3A4 activity. Studies were performed using human liver microsomes and human intestinal S9 fraction, with testosterone as the marker substrate. With the exception of the coumarin and phenolic furanocoumarin derivatives, which were inactive, the alkyloxy-furanocoumarin analogues were found to inhibit CYP3A4 activity in a dose dependent manner, with observed IC50 values ranging from 0.13 +/- 0.03 to 49.3 +/- 1.9 microM. The unsaturated furan derivatives were found to exhibit time-dependent inhibition, showing a 2-, 4- and 14-fold increase in potency for 6',7'-epoxybergamottin, 6',7'-dihydroxybergamottin and bergamottin, respectively after a preincubation period of ten minutes. Reduction of the furan moiety resulted in an 11-fold decrease in inhibitory potency, suggesting that this functional group is key to the interaction between these compounds and CYP3A4.

Individual HIV type 1 envelope-specific T cell responses and epitopes do not segregate by virus subtype

HIV-1 vaccines are often designed to target one or several virus subtype(s). They therefore include antigens (e.g., env or env/gag/pol) from each targeted subtype to elicit subtype-directed immunity. To determine if individual T cells respond to HIV-1 antigens in a subtype-directed manner, we selected four T cell hybridomas, each representative of a different immunodominant response toward a subtype B envelope. Hybridomas were tested for responses toward 20 subtype B envelope proteins and one protein each from subtypes A, C, and D. None of the hybridomas cross-reacted with all subtype B envelopes, yet three responded to a non-B protein. Core epitopes and flanking regions affected responsiveness. This lack of subtype-directed activity was corroborated by analyses of the Los Alamos database; like immune responses, epitope distributions were not dictated by subtype. Results highlight the difficulty of predicting immune responses based on subtype alone and encourage considerations of antigenic disparity in addition to subtype disparity during HIV-1 vaccine design.

DEVELOPMENT OF NOVEL FURANOCOUMARIN DIMERS AS POTENT AND SELECTIVE INHIBITORS OF CYP3A4

Grapefruit juice has been found to cause an increase in the oral bioavailability of many therapeutic agents. Such interactions are believed to result from the mechanism-based inhibition of CYP3A4 activity in the intestine. Furanocoumarin dimers present in the juice have been found to be extremely potent inhibitors of CYP3A4 activity. The aim of this work was to synthesize and test a series of dimers with a view to defining the relationship between structure and inhibitory activity and establish whether they might make suitable probes of CYP3A4 activity. Eleven furanocoumarin dimers were synthesized and evaluated as inhibitors of CYP3A4 using human liver microsomes, with testosterone as the marker substrate. Four of the most potent dimers were also investigated for their effects on CYP3A4 activity in the human intestine and on five additional hepatic cytochrome P450 isoforms. The dimers showed potent dose-dependent inhibition of CYP3A4 activity in both liver and intestine; IC50 values ranged from 0.021 +/- 0.002 to 0.146 +/- 0.041 microM (mean +/- S.D. n = 3). Of the four dimers evaluated further, all showed time-dependent inhibition of CYP3A4 activity. 88Prop showed moderate inhibition of both CYP2C19 and CYP1A2 with IC50 values of 4.42 +/- 0.01 and 1.98 +/- 0.34 microM, 88Octa was found to inhibit CYP2C19 (IC50 = 3.16 +/- 0.01 microM) and 58Prop to inhibit CYP1A2 (IC50 = 2.39 +/- 0.77 microM). Minimal inhibition of CYP2D6 and CYP2C9 was observed (IC50 > 10 microM). In conclusion, all the dimers tested were extremely potent inhibitors of CYP3A4 activity. In particular, dimer 55EE was highly selective toward the enzyme, suggesting that this compound is a suitable probe for determining the contribution of CYP3A4 to drug metabolism.

Long lived multi-isotype anti-HIV antibody responses following a prime-double boost immunization strategy

Despite decades of work, an effective HIV vaccine remains elusive. In an effort to elicit protective immunity, investigators have sought to define vaccines able to elicit durable HIV-specific B-cell and T-cell activities. Additionally, vaccines are sought which can induce antibodies of a variety of isotypes, as each isotype possesses unique attributes in terms of opsonization, Fc receptor binding capacity, complement fixation and location. One prominent new vaccine strategy, applied to numerous distinct antigenic systems is the prime boost-regimen, with DNA, vaccinia virus (VV), and/or purified recombinant protein. To examine the durability, location and isotype distribution of responses induced by prime-boost regimens, we tested successive immunizations with DNA, VV and protein (D-V-P), comparing three forms of protein inoculations: (i) purified protein administered intramuscularly with complete Freunds adjuvant, (ii) purified protein administered intranasally, and (iii) purified protein conjugated to oxidized mannan, administered intranasally. We found that all three protocols elicited serum antibodies of multiple isotypes, with serum IgA being most prominent among mice immunized with mannan-conjugated protein. All D-V-P protocols, regardless of protein form or route, also elicited antibody responses at mucosal surfaces. In bronchoalveolar lavage, a tendency toward IgA production was again most prominent in mice boosted with the protein-mannan conjugate. Both B-cell and T-cell responses were sustained for more than 1 year post-immunization following each form of vaccination. Contemporaneous with long-lasting serum and mucosal antibodies were antibody forming cells in the bone marrow of primed animals. Results highlight the D-V-P vaccination strategy as a promising approach for attaining durable, multi-isotype B-cell and T-cell activities toward HIV.

The diagnosis of von Willebrand disease: a guideline from the UK Haemophilia Centre Doctors' Organization

von Willebrand disease (VWD) is the commonest inherited bleeding disorder. However, despite an increasing understanding of the pathophysiology of VWD, the diagnosis of VWD is frequently difficult because of uncertainty regarding the relationship between laboratory assays and function in vivo. The objective of this guideline is to provide contemporary advice on a rational approach to the diagnosis of VWD. This is the second edition of this UK Haemophilia Centre Doctors' Organisation (UKHCDO) guideline and supersedes the previous edition which was published in 1997.

Response to desmopressin of factors XI, X and V in patients with factor VIII deficiency and von Willebrand disease

Desmopressin [1-deamino-8-d-arginine vasopressin (DDAVP)] has been successfully used in the treatment of type 1 von Willebrand disease (VWD) and mild haemophilia A (MHA). Data suggest that DDAVP can increase factor XI (FXI) plasma levels and may represent an effective treatment for mild FXI deficiency. We assessed the DDAVP response of FXI coagulant activity (FXI:C), FXI antigen (FXI:Ag), factor V coagulant activity (FV:C), and factor X coagulant activity (FX:C) in 33 individuals with VWD or MHA. DDAVP did not produce a clinically significant increase in FXI:C, FXI:Ag, FX:C or FV:C in any patient. The mean +/- SD FXI:C pre-DDAVP (time 0) and at 1 h post-DDAVP was 90.7 (+/-22.9) U/dl and 92.1 (+/-20.9) U/dl, respectively. The mean (+/-SD) FXI:Ag at time 0 and 1 h was 92.2 (+/-20.1) U/dl and 89.9 (+/-21.3) U/dl, respectively. There was a small reduction at 1 h post-DDAVP in both FV:C, from 101.8 (+/-20.9) U/dl to 97.2 (+/-21.4) U/dl (P < 0.001), and FX:C from 103 (+/-19.5) U/dl to 98.8 (+/-18.7) U/dl (P < 0.001). No significant increase in FXI:C, FXI:Ag, FV:C or FX:C levels was seen at 4 h post-DDAVP. This study failed to demonstrate a clinically significant increase in the levels of FXI, FX or FV following administration of DDAVP.

Management of von Willebrand disease: a guideline from the UK Haemophilia Centre Doctors' Organization

von Willebrand disease (VWD) is the commonest inherited bleeding disorder. The aim of therapy for VWD is to correct the two defects of haemostasis in this disorder, impaired primary haemostasis because of defective platelet adhesion and aggregation and impaired coagulation as a result of low levels of factor VIII. The objective of this guideline is to inform individuals making choices about the treatment and management of VWD including the use of therapeutic products. This is the second edition of this UK Haemophilia Centre Doctors' Organization (UKHCDO) guideline and supersedes the previous edition which was published in 1994.

Cellular origin of ionizing radiation-induced NF-kappaB activation in vivo and role of NF-kappaB in ionizing radiation-induced lymphocyte apoptosis

PURPOSE

To investigate the cellular origin of ionizing radiation (IR)-induced NF-kappaB activation in vivo and the role of NF-kappaB in IR-induced lymphocyte apoptosis.

MATERIALS AND METHODS

NF-kappaB activities were analysed by gel shift/supershift assay in isolated murine T- and B-cells, macrophages (MPhi) and tissues from normal and T- and B-cell-deficient Rag1 mice with or without exposure to IR. IR-induced lymphocyte apoptosis was determined by analysis of 3,3'-dihexyloxacarbocyanine iodide (DiOC(6)) uptake, annexin-V staining and the sub-G0/1 population, or by TUNEL assay.

RESULTS

The results showed that IR activated NF-kappaB in lymphocytes, including both T- and B-cells, but failed to do so in MPhi. Furthermore, T- and B-cell-deficient Rag1 mice exposed to IR exhibited a significant reduction in NF-kappaB activation as compared with normal mice. Although NF-kappaB1 (p50) gene knockout or NF-kappaB decoy oligonucleotide treatment specifically inhibited IR-induced lymphocyte NF-kappaB activation, they had no significant effect on IR-induced lymphocyte apoptosis.

CONCLUSIONS

This finding suggests that lymphocytes are the main cellular origin of IR-induced NF-kappaB activation in vivo. However, NF-kappaB activation has no significant effect on IR-induced lymphocyte apoptosis.

Increased clearance of von Willebrand factor antigen post-DDAVP in Type 1 von Willebrand disease: is it a potential pathogenic process?

The mechanism of von Willebrand factor (VWF) clearance is not fully understood. The factors that affect VWF clearance, and the normal in vivo mechanism of clearance, may be relevant to the pathogenesis of Type 1 von Willebrand disease (VWD), in which there is a partial deficiency of VWF. In order to investigate the clearance of VWF in Type 1 VWD, the current study assessed the half-life of VWF antigen (t(1/2) VWF:Ag) in Type 1 VWD patients and individuals with mild hemophilia A following the administration of 1-deamino-8-d-arginine vasopressin (DDAVP; desmopressin). To date 20 individuals have been assessed, 13 with Type 1 VWD and seven with mild hemophilia A. The median t(1/2) VWF:Ag in the Type 1 VWD and mild hemophilia A groups were 4.6 h and 9.5 h, respectively. The difference between the t(1/2) VWF:Ag for the two groups was significant, P < 0.02. Analysis of the data showed a correlation between the t(1/2) VWF:Ag and the baseline VWF:Ag level prior to administration of DDAVP: lower baseline VWF:Ag levels were associated with a shorter t(1/2) VWF:Ag. These data suggest that increased clearance of VWF may be the pathogenic mechanism in some cases of Type 1 VWD.

Short-term calcitriol administration improves calcium homeostasis in adults with cystic fibrosis

Osteoporosis is a well-defined health risk in cystic fibrosis (CF) patients due to many factors. Vitamin D insufficiency, despite routine cholecalciferol supplementation in CF patients, may contribute to a relative secondary hyperparathyroidism and possibly deficient bone mineralization. An alternate form of vitamin D, calcitriol, was studied to determine short-term effects on fractional calcium absorption and other calciotropic markers in 10 adult CF subjects and in 10 age-, sex- and body mass index (BMI)-matched controls. Serum fractional absorption of (45)Ca was determined after a calcium-containing meal prior to calcitriol intervention. Other measurements included serum parathyroid hormone (PTH), ionized calcium, 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)(2)D) and urinary calcium:creatinine and N-telopeptide (NTx) concentrations. Both groups were then given calcitriol (0.5 micro g p.o. b.i.d. for 14 days) and restudied following the same protocol. Both groups increased their fractional absorption of (45)Ca after calcitriol ( p=0.015 CF subjects, p=0.001 controls), although calcitriol tended to be less effective in the CF group compared with the controls ( p=0.055). Post-prandial serum PTH concentrations were suppressed compared with baseline in both groups ( p=0.03 CF subjects, p=0.006 controls). Urinary NTx concentrations, a marker for bone resorption, decreased significantly in CF subjects after calcitriol (96.0+/-16.0 vs 63.9+/-12.7 nmol BCE/mmol Cr, p=0.01) and remained unchanged in the control group. The controls had an increase in serum 1,25(OH)(2)D concentrations (69.9+/-4.2 vs 90.7+/-9.6 pmol/l, p=0.02) while there was no significant change in the CF group. Oral calcitriol administration appears to improve markers of calcium balance in adults with CF by increasing fractional absorption of (45)Ca and lowering PTH concentrations, similar to its known effects in healthy subjects, while also suppressing urinary NTx, a marker of bone turnover.

The role of the platelet function analyser (PFA-100) in the characterization of patients with von Willebrand's disease and its relationships with von Willebrand factor and the ABO blood group

Determination of the closure time (CT) with the platelet function analyser (PFA-100) is a useful screening test for von Willebrand's disease (VWD) but its role in the characterization of VWD is not well established. We studied the relationship between the prolongation of the CT with adenosine diphosphate (ADP) (CT-ADP) and epinephrine (CT-EPI) cartridges and the von Willebrand factor (VWF) in 53 patients with VWD. We found that a relatively small percentage of the prolongation of the CT-ADR and CT-ADP (16 and 29%, respectively) was determined by a reduction in VWF levels. The CT-ADP was significantly more prolonged in the presence of qualitative defects in VWF but could not discriminate between the VWD subtypes. The ABO blood group had no effect on the prolongation of the CT or the bleeding time. In conclusion, the PFA-100 appears of little use in the characterization of severity and subtype of VWD.

Limited breadth of a T-helper cell response to a human immunodeficiency virus envelope protein

Single-envelope human immunodeficiency virus (HIV) vaccines have been studied for more than a decade, with some successes in homologous challenge experiments in nonhuman primates but with no clear successes in clinical trials. To gain insight into the breadth of the immunity elicited by such vaccines, we have dissected the T-helper cell response of C57BL/6 mice to an individual, molecularly cloned envelope protein. Here, we report that T-helper cells responsive to HIV type 1 1035 envelope are very highly restricted in C57BL/6 animals: seven different hybridomas recovered from five separate mice recognized the same peptide, PKVSFEPIPIHYCAP, located in the C2 region of gp120. Three of these hybridomas were tested on a natural variant of the peptide but failed to respond. A more extensive analysis of whole splenic populations from other C57BL/6 mice immunized with the 1035 envelope reproducibly confirmed that the gp120-specific T-helper response was almost exclusively focused on a single epitope. We conclude that single-envelope vaccines may frequently fail to provoke an immune response sufficiently diverse to recognize variant sequences among circulating HIV. The results encourage the inclusion of more than one envelope in future vaccines to enhance the potential diversity and respective surveillance capacities of responding T-helper cell populations.

Effect of renal insufficiency on the pharmacokinetics and pharmacodynamics of benazepril in cats

The effect of renal insufficiency was studied on the pharmacokinetics (PK) and pharmacodynamics (PD) of the angiotensin-converting enzyme (ACE) inhibitor benazepril in cats. The active metabolite of benazepril, benazeprilat, is eliminated principally ( approximately 85%) via biliary excretion in cats. A total of 20 control animals and 32 cats with moderate renal insufficiency induced by partial nephrectomy were used. Assessments were made at steady state after treatment with placebo or benazepril (0.25-2 mg/kg) once daily for a minimum of 10 days. The PK endpoint was the AUC (0-->24 h) of total plasma benazeprilat. The PD endpoints were systolic, diastolic and mean blood pressures (respectively SBP, DBP and MBP) measured by telemetry, and plasma ACE activity, assessed by an ex vivo assay. Renal function was assessed by glomerular filtration rate (GFR), measured by inulin clearance, and plasma creatinine concentrations (1/PCr). As compared with control animals, the renal insufficient cats had a 78% reduction in GFR (0.57 +/- 0.41 mL/min kg), increased plasma creatinine (2.7 +/- 1.0 mg/dL), urea (44.0 +/- 11.9 mg/dL) and ACE activity, and moderately increased blood pressure (SBP 171.8 +/- 5.1 mmHg) (all parameters P < 0.05). Renal insufficient cats receiving benazepril had significantly (P < 0.05) lower SBP, DBP, MBP and ACE, and higher GFR values as compared with placebo-treated animals. There were no significant differences in SBP, DBP, MBP, benazeprilat or ACE values according to the degree of renal insufficiency in cats receiving benazepril. It is concluded that no dose adjustment of benazepril is necessary in cats with moderate renal insufficiency.

Finite-size effects in the conductivity of cluster assembled nanostructures

Atomic clusters have been deposited between lithographically defined contacts with nanometer scale separations. The design of the contacts is based on an appropriate application of percolation theory to conduction in cluster deposited devices and allows finite-size effects to be clearly observed. It is demonstrated, both by experiment and by simulation, that for small contact separations the percolation threshold is shifted to extremely low surface coverages. The selected rectangular contact geometry ensures that wirelike structures are formed close to the percolation threshold.

Experience of prophylaxis treatment in children with severe haemophilia

The practice of prophylactic treatment of boys with severe haemophilia has been evaluated in our centre. Prophylaxis was started at the median age of 3.7 years (range 0.4-12.7 years) in 38/41 children (93%) under 17 years of age. Median follow-up was 4.1 years (range 0.4-12.7 years). The criteria of primary prophylaxis according to the definition by the European Paediatric Network of Haemophilia Management was fulfilled by 9/38 (24%). Although a majority [76%, 29/38] of the children started prophylaxis after a median number of joint bleeds of 3.5, 70% of the children in this group had clinical joint scores of 0. Intravenous catheter insertion was required at a median age of 15.5 months (range 5-36 months) in 21% of the children, resulting in a catheter infection rate of 1.74 per 1000 catheter days. None developed an inhibitor on prophylaxis and three patients who had low-titre inhibitors (< 5 Bethesda units) prior to prophylaxis had undetectable inhibitors after prophylaxis. The home-treatment training programme required considerable time and cost. As a result, 87% of the children used peripheral venous access and hospital visits declined as prophylaxis became established. Parents' incentives for prophylaxis were that the children undertook many physical activities and sports previously not recommended, there was less parental anxiety and an overall improvement in the quality of life for the whole family.

Outcomes of alcohol treatment for adolescents

The use by adolescents and young adults of alcohol and other drugs continues to be a tremendous problem for this nation. Over 30% of all high school students nationwide report episodes of hazardous drinking (five or more drinks on one occasion), when both moderate and heavy alcohol consumption are associated with a higher risk of alcohol-related medical consequences and accidental injuries for youth. Increased awareness and concern related to adolescent substance use has led to the outgrowth of additional treatment facilities and programs for this age group. The current chapter discusses how developmental factors may impact the assessment process and subsequent treatment for adolescent alcohol use disorders. In addition, outcome research, intervention studies, relapse, and factors that may influence the recovery process are discussed.

Abnormal bone turnover in cystic fibrosis adults

Cystic fibrosis (CF) patients often have low bone mineral density (BMD) and may suffer from fractures and kyphosis. The pathogenesis of low BMD in CF is multifactorial. To study bone metabolism, we collected fasting serum and urine from 50 clinically stable CF adults (mean age 28 years) and 53 matched controls to measure markers of bone formation and bone resorption. The CF subjects had moderate lung disease (FEV1: 46.1 +/- 18.6% predicted) and malnutrition (BMI: 20.0 +/- 3.3 kg/m2). Only 3 subjects had normal BMD. CF subjects had higher urinary N-telopeptides of type I collagen (81.0 +/- 60.0 vs 49.0 +/- 24.2 nm BCE/mmol creatinine, p = 0.0006) and free deoxypyridinoline (7.3 +/- 5.0 vs 5.3 +/- 1.9 nM/mM, p = 0.004) levels than controls. Serum osteocalcin levels were similar in the two groups, a result confirmed by two immunoassays that recognize different epitopes on osteocalcin. Serum bone-specific alkaline phosphatase levels were elevated in CF patients (32.0 +/- 11.3 vs 21.8 +/- 7.0 U/l, p < 0.0001), but were much more closely associated with serum total alkaline phosphatase levels (r = 0.51, p = 0.001) than with age or gender. Parathyroid hormone levels were elevated (p = 0.007) and 25-hydroxyvitamin D levels were depressed (p = 0.0002) in the CF patients in comparison with controls. These results indicate that adults with CF have increased bone resorption with little change in bone formation. Medications that decrease bone resorption or improve calcium homeostasis may be effective therapies for CF bone disease.

Prenatal diagnosis of pyruvate dehydrogenase deficiency using magnetic resonance imaging

INTRODUCTION

Pyruvate dehydrogenase deficiency is an inherited inborn error of metabolism associated with early neonatal death and long-term neurologic sequelae in survivors. Prenatal diagnosis currently relies on isolation of fetal cells for subsequent genetic and/or biochemical studies. Magnetic resonance imaging and magnetic resonance spectroscopy have been used on occasion for both postnatal diagnosis and management of pyruvate dehydrogenase deficiency. We illustrate a case in which these non-invasive modalities also prove useful for prenatal diagnosis of this condition.

CASE

A 31-year-old multipara with a history of two prior infants affected with pyruvate dehydrogenase deficiency presented with a spontaneous dichorionic, diamniotic twin pregnancy. Magnetic resonance imaging and magnetic resonance spectroscopy were performed on both fetuses. Magnetic resonance imaging of the presenting (male) fetus demonstrated mild ventriculomegaly, increased extracerebrospinal fluid, and decreased cortical sulcation and gyration. The non-presenting (female) fetus was structurally normal. Magnetic resonance spectroscopy spectra were obtained for both fetuses, and were normal. The diagnosis of pyruvate dehydrogenase deficiency was made in the presenting fetus after delivery on the basis of subsequent mortality from severe lactic acidosis.

CONCLUSION

Prenatal MR imaging of the fetal brain can be used for prenatal diagnosis in fetuses at risk for pyruvate dehydrogenase deficiency. Prenatal MR spectroscopy, although technically feasible, does not appear to have a role in the prenatal diagnosis of this condition.

Depression and posttraumatic stress disorder at three months after mild to moderate traumatic brain injury

To investigate the frequency and risk factors of major depressive disorder (MDD) after mild to moderate traumatic brain injury (TBI), 69 TBI and 52 general trauma (GT) patients were prospectively recruited and studied at 3-months postinjury. There was a nonsignificant difference in the proportion of MDD patients in the TBI and GT groups. Therefore, a composite MDD group (TBI and GT patients) was compared to patients who were nondepressed. Female gender was related to MDD, but no other risk factors were identified. MDD was associated with disability (Glasgow Outcome Scale, Community Integration Questionnaire) and cognitive impairment. MDD was comorbid with posttraumatic stress disorder. Implications for postacute management of mild to moderate TBI are discussed.

Progression into and out of binge drinking among high school students

The current study examined binge drinking among high school students over an academic year. Adolescent drinkers (N = 621; 58% female) were grouped into 4 trajectories: drinkers (35%), increasers (14%), decreasers (16%), and persistent binge drinkers (35%). Prospective analyses indicated several factors that predicted escalation and de-escalation of binge drinking. Increasers were more likely to regularly use alcohol and cigarettes at a younger age than drinkers. Compared with decreasers, persistent binge drinkers reported regular alcohol and marijuana use at younger ages. Lower levels of perceived student drinking appeared to be a protective factor for onset of binge drinking. The results highlight the need to study precursors to the naturally occurring fluctuations in binge drinking and suggest factors that may accentuate the risk of binge drinking.

ALDH2 status, alcohol expectancies, and alcohol response: preliminary evidence for a mediation model

BACKGROUND

A genetic variant in the alcohol-metabolizing enzyme (aldehyde dehydrogenase; ALDH2*2 allele), common in individuals of Asian heritage, has been associated with both physiologic response to alcohol and alcohol consumption. Prior research has also demonstrated that those with ALDH2*2 alleles have lower positive alcohol expectancies than those without these alleles. This preliminary study was designed to test whether the level of response to alcohol is the mechanism by which ALDH2 status may affect alcohol expectancies.

METHODS

Data were collected from 32 Asian American college students (14 women and 18 men). By use of a randomized, double-blind design, participants were administered oral placebo and alcohol at separate laboratory sessions. Data included blood tests to establish ALDH2 status, questionnaire measures of demographic information and alcohol expectancy, and several physiologic measures collected after placebo and alcohol administration.

RESULTS

ALDH2 status was related to alcohol response measures for both men and women. ALDH2 status was also related to tension reduction expectancies for women and to expectancies for cognitive behavioral impairment for men. In the male sample, the ALDH2/expectancy relationship was fully explained by the level of response to alcohol.

CONCLUSIONS

These results represent a first step in understanding the mechanisms by which genetic factors, such as ALDH2 status, can affect alcohol-related learning.

The effect of repeated ethylene oxide sterilization on the mechanical strength of synthetic absorbable sutures

The purpose of this study was to determine the effect of repeated ethylene oxide sterilization using a standard clinical protocol on sutures, a type of medical device labeled for single use and reported to be reprocessed for use after being opened but not used. Four types of commonly used synthetic absorbable sutures were subjected to 1 and 2 ethylene oxide resterilization cycles. Knot tensile strength was determined for new sutures and for sutures that had been subjected to 1 and 2 ethylene oxide resterilization cycles. As has been found with other types of single-use devices, no general conclusions can be made for absorbable sutures. The strengths of different types of sutures increased, decreased, or stayed the same after repeated sterilization. In addition, the inner packages of some sutures were not intact after reprocessing, possibly exposing the sutures to increased humidity, which can produce degradation leading to loss of strength both immediately and after additional shelf aging and degraded performance after clinical use.

Studies of a targeted risk reduction intervention through defined exercise (STRRIDE)

PURPOSE

The Studies of a Targeted Risk Reduction Intervention through Defined Exercise (STRRIDE) trial is a randomized controlled clinical trial designed to study the effects of exercise training regimens differing in dose (kcal.wk-1) and/or intensity (relative to peak VO2) on established cardiovascular risk factors and to investigate the peripheral biologic mechanisms through which chronic physical activity alters carbohydrate and lipid metabolism to result in improvements in these parameters of cardiovascular risk in humans.

METHODS

We will recruit 384 subjects and randomly assign them to one of three exercise training regimens or to a sedentary control group. The recruiting goal is to attain a subject population that is 50% female and 30% ethnic minority. The overall strategy is to use graded exercise training regimens in moderately overweight subjects with impairments in insulin action and mild to moderate lipid abnormalities to investigate whether there are dose or intensity effects and whether adaptations in skeletal muscle (fiber type, metabolic capacity, and/or capillary surface area) account for improvements in insulin action and parameters of lipoprotein metabolism. We will study these variables before and after exercise training, and over the course of a 2-wk detraining period. The study sample size is chosen to power the study to examine differences in responses between subjects of different gender and ethnicity to exercise training with respect to the least sensitive parameter-skeletal muscle capillary density.

RESULTS

The driving hypothesis is that improvements in cardiovascular risk parameters derived from habitual exercise are primarily mediated through adaptations occurring in skeletal muscle.

CONCLUSION

Identification that amount and intensity of exercise matter for achieving general and specific health benefits and a better understanding of the peripheral mechanisms mediating the responses in carbohydrate and lipid metabolism to chronic physical activity will lead to better informed recommendations for those undertaking an exercise program to improve cardiovascular risk.

Psychosocial treatments for schizophrenia

As indicated in recent treatment guidelines, psychosocial treatments play a critical role in the rehabilitation of schizophrenia patients. During the past few years, novel psychosocial treatments have emerged expanding the scope of successful outcomes and designed to address the specific deficits inherent in schizophrenia. This paper provides a brief description and evaluate the efficacy of five new emerging psychosocial treatments for schizophrenia. There is strong evidence for the efficacy of supported employment programs and family therapy, especially those involving multiple family interactions. Although schizophrenia patients appear to derive benefit from cognitive behavioral therapy, no evidence supports it superiority over that of other individual psychotherapies. The trials of cognitive remediation to date have been largely unsuccessful, although new innovative approaches continue to be tested. Finally, substance use treatment specifically designed to address the deficits in schizophrenia patients have been formulated, which are supported by optimistic pilot data and awaiting the completion of on-going clinical trials.

Overlapping functions of the cell adhesion molecules Nr-CAM and L1 in cerebellar granule cell development

The structurally related cell adhesion molecules L1 and Nr-CAM have overlapping expression patterns in cerebellar granule cells. Here we analyzed their involvement in granule cell development using mutant mice. Nr-CAM-deficient cerebellar granule cells failed to extend neurites in vitro on contactin, a known ligand for Nr-CAM expressed in the cerebellum, confirming that these mice are functionally null for Nr-CAM. In vivo, Nr-CAM-null cerebella did not exhibit obvious histological defects, although a mild size reduction of several lobes was observed, most notably lobes IV and V in the vermis. Mice deficient for both L1 and Nr-CAM exhibited severe cerebellar folial defects and a reduction in the thickness of the inner granule cell layer. Additionally, anti-L1 antibodies specifically disrupted survival and maintenance of Nr-CAM-deficient granule cells in cerebellar cultures treated with antibodies. The combined results indicate that Nr-CAM and L1 play a role in cerebellar granule cell development, and suggest that closely related molecules in the L1 family have overlapping functions.

Biomass byproducts for the remediation of wastewaters contaminated with toxic metals

Pollution of the environment with toxic metals is widespread and often involves large volumes of wastewater. Remediation strategies must be designed to support high throughput while keeping costs to a minimum. Biosorption is presented as an alternative to traditional physicochemical means for removing toxic metals from wastewater. We have investigated the metal binding qualities of two biomass byproducts that are commercially available in quantity and at low cost, namely "spillage", a dried yeast and plant mixture from the production of ethanol from corn, and ground corn cobs used in animal feeds. The biomass materials effectively removed toxic metals, such as Cu, Cs, Mo, Ni, Pb, and Zn, even in the presence of competing metals likely to be found in sulfide mine tailing ponds. The effectiveness of these biosorbents was demonstrated using samples from the Berkeley Pit in Montana. Investigations included column chromatography and slurry systems, and linear distribution coefficients are presented. X-ray spectroscopy was used to identify the binding sites for metals adsorbed to the spillage material. The results of our experiments demonstrate that the biosorption of metals from wastewaters using biomass byproducts is a viable and cost-effective technology that should be included in process evaluations.

Diagnostic differences in social anhedonia: a longitudinal study of schizophrenia and major depressive disorder

This study examined the hypothesis that, in schizophrenia, elevated trait social anhedonia (SA) is a stable individual difference, whereas in depression, increased SA is a reflection of a current clinical state that will diminish with recovery. Differences in trait Negative Affect (NA) and Positive Affect (PA) were also examined. Individuals with schizophrenia (n = 55) and depression (n = 34) were evaluated at baseline during hospitalization and compared with nonpsychiatric control participants (n = 41). Participants were assessed again at a 1-year follow-up. At baseline, compared with control participants, individuals with schizophrenia and depression were both characterized by elevated SA, greater NA, and lower PA. In schizophrenic individuals, elevated SA remained stable over the follow-up. However, in recovered depressed patients, SA declined over the follow-up period. Group differences remained in NA and PA over the 1-year follow-up. These results support the view that elevated SA is enduring in schizophrenia but that elevated SA is transiently related to clinical status in depression.

The effects of use and simulated reuse on percutaneous transluminal coronary angioplasty balloons and catheters

A series of studies was undertaken to determine the effects of single patient use and simulated reuse on percutaneous transluminal coronary angioplasty (PTCA) balloon catheters. Catheters were retrieved from Walter Reed Army Medical Center and were low-level disinfected and cleaned at the US Food and Drug Administration. They were then tested for balloon compliance, and the results were compared against the manufacturer's specifications. Selected groups of catheters were subjected to EO-resterilization and a simulated reuse protocol. The results demonstrated that the effects of use and EO-resterilization is model specific. Furthermore, some balloons demonstrated a time-dependent behavior while others recovered from the effects of simulated reuse by compliance testing at high pressure. Testing for the slipperiness of the catheters after repeated EO-resterilization also demonstrated that changes were model specific.

Diagnostic differences in social anhedonia: a longitudinal study of schizophrenia and major depressive disorder

This study examined the hypothesis that, in schizophrenia, elevated trait social anhedonia (SA) is a stable individual difference, whereas in depression, increased SA is a reflection of a current clinical state that will diminish with recovery. Differences in trait Negative Affect (NA) and Positive Affect (PA) were also examined. Individuals with schizophrenia (n = 55) and depression (n = 34) were evaluated at baseline during hospitalization and compared with nonpsychiatric control participants (n = 41). Participants were assessed again at a 1-year follow-up. At baseline, compared with control participants, individuals with schizophrenia and depression were both characterized by elevated SA, greater NA, and lower PA. In schizophrenic individuals, elevated SA remained stable over the follow-up. However, in recovered depressed patients, SA declined over the follow-up period. Group differences remained in NA and PA over the 1-year follow-up. These results support the view that elevated SA is enduring in schizophrenia but that elevated SA is transiently related to clinical status in depression.

D609 inhibits ionizing radiation-induced oxidative damage by acting as a potent antioxidant

Tricyclodecan-9-yl-xanthogenate (D609) has been extensively studied in biological systems and exhibits a variety of biological functions, including antiviral, antitumor, and anti-inflammatory activities. Most of these activities have been largely attributed to the inhibitory effect of D609 on phosphatidylcholine-specific phospholipase C. However, as a xanthate derivative, D609 is a strong electrolyte and readily dissociates to xanthate anions and cations of alkali metals in solution. Xanthate anions and protonated xanthic acid contain a free thiol moiety and are highly reductive. This implies that D609 and other xanthate derivatives may function as potent antioxidants. Indeed, we found that D609 inhibited the Fenton reaction-induced oxidation of dihydrorhodamine 123 in a dose-dependent manner similar to that of pyrrolidinedithiocarbamate, a well known antioxidant. In addition, D609 inhibited the formation of the alpha-phenyl-tert-butylnitrone-free radical spin adducts and lipid peroxidation of synaptosomal membranes by the Fenton reagents. Furthermore, preincubation of lymphocytes with D609 resulted in a significant diminution of ionizing radiation (IR)-induced 1) production of reactive oxygen species; 2) decrease in intracellular reduced glutathione; 3) oxidative damage to proteins and lipids; and 4) activation of nuclear factor-kappaB. Moreover, when D609 (50 mg/kg i.v.) was administered to mice 10 min prior to total body IR (6.5 and 8.5 Gy), it protected the mice from IR-induced lethality. Thus, these results indicate that D609 is a potent antioxidant and has the ability to inhibit IR-induced cellular oxidative stress.

Effects of NF-kappaB1 (p50) targeted gene disruption on ionizing radiation-induced NF-kappaB activation and TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA expression in vivo

PURPOSE

To investigate the role of the NF-kappaB1 (p50) gene in ionizing radiation (IR)-induced NF-kappaB activation and TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA expression in vivo.

MATERIALS AND METHODS

NF-kappaB activation was analysed by the gel shift/supershift assay and the levels of TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA were measured using RNase protection assay (RPA). Various tissues from BALB/c, B6,129P-Nfkb1 (NF-kappaB1 or p50 gene knockout, p50(-/-)) and B6,129PF2 (wild-type, p50(+/+)) mice were analysed before or after exposure to a lethal dose (8.5 Gy) of total-body gamma-irradiation.

RESULTS

Exposure of BALB/c mice to total-body IR selectively activated NF-kappaB in the spleen, mesenteric lymph nodes (LN) and bone marrow (BM). Gel supershift assay using polyclonal antibodies against NF-kappaB p50, p65 or c-Rel protein revealed that the NF-kappaB p50 subunit is a critical component of the NF-kappaB complexes activated by IR in vivo. Discretely augmented TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA expression was found in the spleen, LN and BM after BALB/c mice received IR. However, mice lacking the p50 gene (p50(-/-)) showed a significant reduction in IR-induced activation of NF-kappaB and increases in TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA expression, as compared with that of wild-type mice (p50(+/+)).

CONCLUSIONS

The NF-kappaB p50 subunit is a critical component of the NF-kappaB complexes activated by IR and it plays an important role in mediating IR-induced TNFalpha, IL-1alpha, IL-1beta and IL-6 mRNA expression in vivo.

Four-year outcomes from adolescent alcohol and drug treatment

OBJECTIVE

Knowledge of treatment response for alcohol and drug problems among adults is mounting; less is known about long-term outcome for adolescents who receive treatment for alcohol and drug problems. The current study examined youth substance involvement over 4 years (using five waves of data collection) following treatment for alcohol and drug abuse.

METHOD

A cohort of youth (N = 162, 60% male) treated during adolescence (mean age = 16 years) was followed into young adulthood, a period associated with stabilization of alcohol use patterns and elevated risk for life problems secondary to both alcohol and drug use. Participants (14-18 years old) were consecutive admissions to inpatient adolescent alcohol and drug treatment centers in San Diego that were abstinence focused and based on the 12-step approach.

RESULTS

Alcohol and other drug use were reduced during the 4 years posttreatment, with the exception of nicotine. The greatest prevalence reduction occurred for stimulants; modest changes were evident in alcohol and marijuana use. Nicotine was the most commonly used substance throughout the 4 years after treatment. Several distinct substance involvement trajectories were evident during the 4 years following treatment.

CONCLUSIONS

Alcohol and drug use patterns during the 4 years following treatment highlight both changes and diversity in substance involvement as youth make the transitions from middle to late adolescence and into young adulthood. Findings demonstrate the importance of identifying transitional periods and the need for alternative intervention strategies that may help the progression of this population into young adulthood.

Circadian rhythms: mop up the clock!

All circadian clock genes discovered in Drosophila have mammalian counterparts with extensive sequence homology. Similarities and differences have been identified between insect and mammalian oscillators. Recent studies have shed new light on two mammalian clock components: Mop3 and Per2.

Holoprosencephaly due to mutations in ZIC2: alanine tract expansion mutations may be caused by parental somatic recombination

We report on the prevalence of mutations in the zinc finger transcription factor gene, ZIC2, in a group of 509 unrelated individuals with isolated holoprosencephaly (HPE) and normal chromosomes. Overall, we encountered 16 HPE patients (from 15 unrelated families) with ZIC2 mutations. Thus, ZIC2 mutation was the apparent cause of HPE in 3-4% of cases. Seven mutations were frameshifts that were predicted to result in loss of function, further supporting the idea that ZIC2 haploinsufficiency can result in HPE. One mutation, an alanine tract expansion which is caused by the expansion of an imperfect trinucleotide repeat, occurred in seven patients from six different families. In three of those families, the father was found to be apparently mosaic for the mutation. We hypothesize that this mutation can arise through errors in somatic recombination, an extremely unusual mutation mechanism. In addition, one mutation resulted in a single amino acid change and one mutation was an in-frame deletion of 12 amino acids. The central nervous system malformations seen in patients with ZIC2 mutations ranged from alobar HPE (most common) to middle interhemispheric fusion defect (one case). Although severe facial anomalies are common in HPE, all of the patients with ZIC2 mutations had relatively normal faces, suggesting that ZIC2 mutations represent a large proportion of HPE cases without facial malformation.

Effects of dietary protein on glomerular mesangial area and basement membrane thickness in aged uninephrectomized dogs

The primary objective of this study was to determine the effects of diets containing 18% or 34% protein on glomerular mesangial area (GMA) and basement membrane thickness (GBMT) in uninephrectomized aged dogs. A secondary objective was to determine the combined effects of aging and uninephrectomy on GMA and GBMT in dogs. Ten clinically healthy, pure-bred dogs were unilaterally nephrectomized at about 8 y of age. After 2 mo, 5 dogs were fed an 18% protein diet and 5 dogs were fed a 34% protein diet for 48 mo. At month 48, the dogs were euthanized and the remaining kidney was collected. Samples of kidney from both times of collection were used to measure GMA and GBMT using electron microscopy. The effects of diet on GMA and GBMT were analyzed (student's t-test) using necropsy/nephrectomy score ratios. The effects of time-nephrectomy were determined by comparing nephrectomy values for GMA and GBMT with necropsy values (paired t-test). Dogs fed 34% dietary protein did not have a significant increase in GMA and GBM thickness when compared to dogs fed the 18% protein diet. A significant increase in GMA and GBMT occurred with time-nephrectomy (P = 0.011 and 0.018, respectively). Although dietary protein intake was not a significant factor in causing structural changes to glomeruli in uninephrectomized aged dogs, the power to detect a difference was low. However, significant effects of aging and nephrectomy were detected despite the low power of the study. These results suggest that the increases in GMA and GBMT that occur over time are not markedly influenced by dietary protein intake. However, subtle protein effects cannot be eliminated as a possibility based on this study.

Prevalence of adolescent substance use disorders across five sectors of care

OBJECTIVE

To examine the prevalence of substance use disorders (SUDs) among adolescents who received services in one or more of the following public sectors of care: alcohol and drug (AD), juvenile justice (JJ), mental health (MH), public school-based services for youths with serious emotional disturbance (SED), and child welfare (CW), in relation to age, gender, and service sector affiliation.

METHODS

Participants included 1,036 adolescents aged 13 to 18 years, randomly sampled from all youths who were active in at least one of the above five sectors of care (N = 12,662) in San Diego County California. SUDs were assessed through structured diagnostic interviews conducted from October 1997 through January 1999.

RESULTS

SUDs were found for youths in all sectors of care, with lifetime rates of 82.6% in AD, 62.1% in JJ, 40.8% in MH, 23.6% in SED, and 19.2% in CW. Rates of SUDs were significantly higher among older youths and males. Sector differences held even when accounting for the effects of age and gender.

CONCLUSIONS

SUDs are highly prevalent among youths receiving care in the AD service sector as well as other sectors, particularly JJ and MH. These findings have implications for assessment, treatment, and service coordination for youths with SUDs in diverse sectors of public care.

Adolescent substance use and sexual risk-taking behavior

PURPOSE

To examine the relationship of adolescent substance use and dependence to sexual risk-taking behavior in late adolescence and young adulthood.

METHODS

We prospectively examined self-reported sexual behaviors and substance involvement questionnaires in a sample of youth in substance abuse treatment programs and a comparison sample of sociodemographically similar community youths without histories of substance use disorders recruited from media ads. Assessments of sexual behaviors and substance involvement (78% white, 51% female) were collected at 2, 4, and 6 years after initial assessments, as they transitioned from middle adolescence to young adulthood (from age 15.5 to age 21.5 years, on average). The two samples were compared using Chi-square, analysis of variance, and multivariate analysis of variance approaches. Continuous indicators of high-risk sexual behaviors and substance involvement were analyzed with multiple regression.

RESULTS

Earlier age of onset to sexual activity, more sexual partners, less consistent use of condoms, more sexually transmitted diseases (STDs), and greater prevalence of human immunodeficiency virus testing were reported by youth in the clinical treatment sample relative to sociodemographically comparable nonabusing community youth. High rates of STDs were found among females, and more substance-abusing females reported pregnancies than community females. Substance involvement continued to be associated with high-risk sexual behavior throughout the transition into young adulthood.

CONCLUSIONS

Youth identified with substance problems are more likely to engage in risky sexual behaviors during adolescence and to continue risky sexual behaviors to the extent that substance problems persist. Risk reduction education should be included with adolescent substance abuse treatment.

Effects of the angiotensin converting enzyme inhibitor benazepril in cats with induced renal insufficiency

OBJECTIVE

To determine effects of the angiotensin converting enzyme inhibitor benazepril in cats with induced renal insufficiency.

ANIMALS

32 cats.

PROCEDURE

Renal mass was surgically reduced, and cats were assigned to 1 of 4 eight-cat groups. Group 1 received placebo, whereas groups 2, 3, and 4 received benazepril hydrochloride orally once daily for approximately 6.5 months at the following doses: group 2, 0.25 to 0.50 mg/kg of body weight; group 3, 0.50 to 1.00 mg/kg; and group 4, 1.00 to 2.00 mg/kg. Arterial blood pressures, glomerular filtration rate (GFR), and renal plasma flow were determined before treatment and during the treatment period. Other determinants of renal hemodynamics were measured by use of micropuncture techniques. Renal biopsy specimens were examined microscopically.

RESULTS

Compared with cats that received placebo, mean systolic arterial blood pressure was significantly less and GFR significantly greater in cats that received benazepril. Glomerular capillary pressure and the ratio of efferent to afferent arteriolar vascular resistance were also significantly less in treated cats. However, histologic differences in renal specimens were not detected.

CONCLUSIONS AND CLINICAL RELEVANCE

Treatment with benazepril sustained single nephron GFR in remnant nephrons of cats with induced renal insufficiency. Administration of benazepril was also associated with a small but significant reduction in degree of systemic hypertension and an increase in whole kidney GFR. Benazepril may be an effective treatment to slow the rate of progression of renal failure in cats with renal disease.

Psychometric evaluation of the marijuana and stimulant effect expectancy questionnaires for adolescents

Alcohol expectancies are important in the mediation and prediction of alcohol use. Expectancies for the effects of other drugs, although less well delineated, appear equally important. Therefore, development and validation of expectancy measures for drugs other than alcohol is necessary for evaluating the importance of these constructs. We examined the factor structure, reliability, and validity of the Marijuana Effect Expectancy Questionnaire (MEEQ) and the Stimulant Effect Expectancy Questionnaire (SEEQ) in clinical and community samples of adolescents as they moved into young adulthood (N=279). Confirmatory factor analyses (CFAs) supported the a priori factors, and we found good reliability for most individual scales. Temporal stability and convergent and discriminant validity of drug effect expectancies were supported in this sample of adolescents and young adults. Drug effect expectancies were associated with drug preference and drug use patterns over 2 years. Use of these measures may aid our understanding of the etiology and course of marijuana and stimulant involvement during adolescence and young adulthood.

Factor analysis of an outcome interview for use in clinical trials of traumatically brain-injured patients: a preliminary study

OBJECTIVE

To study the factor structure, internal consistency, concurrent validity, and sensitivity to detect change in patient report of problems of a structured interview in relationship with accepted outcome measures.

DESIGN

Outcome status of patients with severe traumatic brain injury participating in a randomized, phase III, multicenter clinical trial was assessed at 6 mo postinjury using the Glasgow Outcome Scale, the Disability Rating Scale, and the Severe Traumatic Brain Injury Outcome Interview.

RESULTS

Exploratory factor analysis of the Severe Traumatic Brain Injury Outcome Interview produced a meaningful five-factor model: (1) activities of daily living; (2) cognitive; (3) affective; (4) behavioral; and (5) instrumental activities of daily living. The internal consistency of the factors ranged from moderate (0.61 instrumental activities of daily living) to high (0.94 activities of daily living); the interfactor correlations were moderate. The summed factor scores were significantly correlated with measures of global outcome: the Glasgow Outcome Scale (r = 0.66; P < 0.0001) and the Disability Rating Scale (r = 0.61; P < 0.0001). Patient report of cognitive problems correlated moderately with the neuropsychological tests. The summed factor scores were sensitive to change over time.

CONCLUSIONS

Overall, the interview assessed the major important features of outcome pertinent to traumatic brain injury and demonstrated greater sensitivity to subtle changes over time than the unidimensional approaches, such as the Glasgow Outcome Scale and Disability Rating Scale.