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.

fMRI measurement of brain dysfunction in alcohol-dependent young women

BACKGROUND

Studies of brain functioning in alcohol-dependent adults have produced varied results but generally suggest that alcohol affects brain functioning and that relatively short durations of heavy drinking may adversely affect women. It remains unclear when in the course of alcohol dependency and at which developmental stage these brain changes emerge. Our neuropsychological studies have indicated that drinking-related neurocognitive effects occur as early as adolescence (Brown et al., 2000; Tapert & Brown, 1999). This study seeks to characterize brain regions that subserve the affected neurocognitive functions.

METHODS

Alcohol-dependent young women (n = 10) were recruited from a longitudinal study of alcohol- and drug-abusing youth, all of whom met criteria for alcohol dependence. Control participants (n = 10) had no history of alcohol or drug problems and were comparable with alcohol-dependent participants on age (18-25 years), family history of alcohol use disorders, and education. After a minimum of 72 hr of abstinence, functional magnetic resonance imaging, neuropsychological, alcohol/drug involvement, and mood data were collected. Participants performed spatial working memory and vigilance tasks during functional magnetic resonance imaging acquisition to probe brain response.

RESULTS

Alcohol-dependent women demonstrated significantly less blood oxygen level-dependent response than controls during the spatial working memory task in the right superior and inferior parietal, right middle frontal, right postcentral, and left superior frontal cortex, after controlling for the baseline vigilance response.

CONCLUSIONS

Working memory produces a larger neuronal response in some cortical regions than vigilance. Alcohol-dependent women showed less differential response to working memory than controls in frontal and parietal regions, especially in the right hemisphere. Heavy, chronic drinking appears to produce adverse neural effects that are detectable by functional magnetic resonance imaging.

Thorium in mineral products

Many ores contain low levels of thorium. When these ores are processed, the associated radioactivity can be found in mineral concentrates, intermediates and final products. There is an incentive for industries to remove radioactivity from mineral products to allow the movement and sale of these materials, both nationally and internationally, without the need for licensing. Control of thorium in various products involves the development and optimisation of process steps to be able to meet product specifications. The Australian Nuclear Science and Technology Organisation (ANSTO) has undertaken a range of R & D programmes targeting the treatment of thorium-bearing minerals. This paper discusses the application of a microprobe technique for siting radioactivity in zircon and ilmenite and the problems experienced in measuring the concentrations in solid rare earth products.

The Starr County Diabetes Education Study: development of the Spanish-language diabetes knowledge questionnaire

OBJECTIVE

This study reports the psychometric properties of the 24-item version of the Diabetes Knowledge Questionnaire (DKQ).

RESEARCH DESIGN AND METHODS

The original 60-item DKQ was administered to 502 adult Mexican-Americans with type 2 diabetes who are part of the Starr County Diabetes Education Study. The sample was composed of 252 participants and 250 support partners. The subjects were randomly assigned to the educational and social support intervention (n = 250) or to the wait-listed control group (n = 252). A shortened 24-item version of the DKQ was derived from the original instrument after data collection was completed. Reliability was assessed by means of Cronbach's coefficient alpha. To determine validity, differentiation between the experimental and control groups was conducted at baseline and after the educational portion of the intervention.

RESULTS

The 24-item version of the DKQ (DKQ-24) attained a reliability coefficient of 0.78, indicating internal consistency, and showed sensitivity to the intervention, suggesting construct validation.

CONCLUSIONS

The DKQ-24 is a reliable and valid measure of diabetes-related knowledge that is relatively easy to administer to either English or Spanish speakers.

A multivariate process model of adolescent 12-step attendance and substance use outcome following inpatient treatment

A common recommendation for youth treated for substance abuse is to attend 12-step groups. However, little is known regarding the effects of this adult-derived prescription on substance use outcomes for teens. This study examined (a) the relation between 12-step attendance and substance use outcome in the 6 months postdischarge from inpatient care and (b) a process model of how 12-step attendance during the first 3 months postdischarge affects proximal outcomes of motivation, coping, and self-efficacy, measured at 3 months, and how these, in turn, affect ultimate substance use outcome in the following 3 months. Adolescent inpatients (N = 99) were assessed during treatment and 3 and 6 months postdischarge. Results revealed modest beneficial effects of 12-step attendance, which were mediated by motivation but not by coping or self-efficacy. Findings suggest that closer attention be paid to motivational factors in the treatment of adolescent substance abuse.

Prevalence of amblyopia and associated refractive errors in an adult population in Victoria, Australia

The study aimed to describe the prevalence of amblyopia and associated refractive errors among an adult Australian population. The Visual Impairment Project (VIP) is a population-based study of age-related eye disease in the state of Victoria, Australia. Data were collected through standardised interviews and orthoptic and ophthalmic dilated examinations. Amblyopia was defined as best-corrected visual acuity of 6/9 or worse in the absence of any pathological cause. The participants were 3,265 urban residents and 1,456 rural residents of the VIP ranging in age from 40-92 years (mean = 59 years; 53% female). The prevalence of unilateral amblyopia was 3.06% (95% C.I. 2.59, 3.53). Amblyopia was not found to be statistically different by age group (p=0.096), gender (p=0.675), or place of birth (p=0.14). Anisometropia was statistically more common (p<0.001) in amblyopic cases (51.1%) compared to the normal population (9.7%), and 54% of amblyopic eyes had visual acuity of worse than 6/12. Amblyopia is a significant cause of unilateral reduced visual acuity in a population aged 40 years and older. Anisometropia was more prevalent and the degree of anisometropia was greater in the amblyopic group compared with the normal population. Oblique astigmatism was more prevalent in the amblyopic group compared with the normal population.

Safety and cleaning of medical materials and devices

A study was undertaken to evaluate different procedures to safely remove microorganisms, protein, and mammalian cells from materials and provide a suitable method for cleaning and assessing effectiveness of cleaning medical devices for reuse or for analysis of failure. Safety considerations for the personnel performing the cleaning or handling the device after cleaning are important issues. Polystyrene plates (96 well) were used to simulate device surfaces not amenable to manual scrubbing. Staphylococcus epidermidis, Candida albicans, Escherichia coli, Pseudomonas aeruginosa, and oral flora were grown in the plates. The plates were stained with crystal violet and the optical densities recorded. The results indicated that E. coli did not adhere well and Pseudomonas formed clumps that were easily detached from the surface of the plates. However, S. epi, C. albicans, and the oral organisms formed adherent biofilms that were difficult to remove from the plates. Detergents with enzymes and sodium hypochlorite (NaOCl) bleach were both effective in removing the biofilm. Other detergents and surfactants were not effective. The aldehyde agents did not remove the organisms and made further cleaning difficult. Allowing the biofilm to dry first made cleaning very difficult. Only the NaOCl bleach could subsequently remove the dried or aldehyde fixed organisms from the wells. The same 96-well polystyrene plate format was used to measure the amount of protein and cell adherence as well as the effectiveness of subsequent cleaning. Bradford reagent was used to detect protein as a measure of the cleaning efficacy. As with the bacteria, NaOCl bleach was effective at removing the protein and cells that had been dried or fixed by formalin or alcohol, whereas detergent with enzymes was not very effective. This study confirmed that used medical devices, contaminated with microorganisms, protein, and/or mammalian cells, should not be allowed to dry before cleaning and that a thorough cleaning procedure should precede sterilization or disinfection (with the exception of NaOCl bleach which also cleans).

Comparison of plasma pharmacokinetics and bioequivalence of ceftiofur sodium in cattle after a single intramuscular or subcutaneous injection

Ceftiofur sodium, a broad-spectrum cephalosporin, is active against gram-positive and gram-negative pathogens of veterinary importance. This study was designed to compare the bioequivalence of the sodium salt in cattle after a single intramuscular (i.m.) or subcutaneous dose (s.c.) of 2.2 mg ceftiofur equivalents/kg body weight. The criteria used to evaluate bioequivalence were (1) the area under the curve from time of injection to the limit of quantitation (LOQ) of the assay (AUC0-LOQ), and (2) time concentrations remained above 0.2 microg/mL (t>0.2). Twelve crossbred beef cattle were enrolled in a three-period, two-treatment crossover trial, with a minimum 2-week washout period between doses of 2.2 mg ceftiofur equivalents/kg. Blood samples were collected serially for up to 72 h post-injection. Plasma samples were then analyzed using a validated assay that measures ceftiofur, and all desfuroylceftiofur-related metabolites, by high-performance liquid chromatography (HPLC) as the stable derivative, desfuroylceftiofur acetamide. A maximum plasma concentration (Cmax) of 13.9+/-3.55 microg/mL was observed from 0. 67-2.0 h after i.m. administration, whereas a Cmax of 13.6+/-3.85 microg/mL was observed from 0.67-3.0 h after s.c. administration. The AUC0-LOQ was 108+/-35.0 microg. h/mL after i.m. dosing, compared with 105+/-29.8 microg. h/mL after s.c. dosing. The pre-established criterion for equivalence of the AUC0-LOQ for the i.m. and s.c. routes of administration was satisfied. The t>0.2 was 49.2+/-8.55 h after i.m. administration, compared with 47.0+/-9.40 h after s.c. administration. The pre-established criterion for equivalence of the t>0.2 for i.m. and s.c. administration was satisfied. The equivalence of AUC0-LOQ and t>0.2 for i.m. and s.c. administration of 2.2 mg ceftiofur equivalents (CE)/kg doses of ceftiofur sodium suggest similar therapeutic efficacy and systemic safety for the two routes of administration.

The role of genetic counseling in the management of prenatally detected congenital heart defects

Genetic counseling should be used in the context of prenatal diagnosis of congenital heart defects for several reasons. The insight gathered through the family history, review of ultrasound findings, and chromosome analysis may help to determine the origin of the defect, such that more precise information about prognosis and recurrence risks can be given. This information should be used by the patient to consider options for the current pregnancy and management of future ones. The difficult and emotionally charged decisions that come with prenatal diagnosis of congenital heart defects demand that the psychosocial burden be explored with the patient. Genetic counseling should facilitate the decision-making process and address patient needs. Genetic counselors have the training, experience, and time to focus on these elements. The role of genetic counseling in congenital heart defects is likely to increase as advances in understanding the underlying genetic causes are made and incorporated into patient care and counseling. Genetic counseling for this indication will become more common as prenatal detection improves and as more affected individuals live to reproductive age.

Resetting of circadian time in peripheral tissues by glucocorticoid signaling

In mammals, circadian oscillators reside not only in the suprachiasmatic nucleus of the brain, which harbors the central pacemaker, but also in most peripheral tissues. Here, we show that the glucocorticoid hormone analog dexamethasone induces circadian gene expression in cultured rat-1 fibroblasts and transiently changes the phase of circadian gene expression in liver, kidney, and heart. However, dexamethasone does not affect cyclic gene expression in neurons of the suprachiasmatic nucleus. This enabled us to establish an apparent phase-shift response curve specifically for peripheral clocks in intact animals. In contrast to the central clock, circadian oscillators in peripheral tissues appear to remain responsive to phase resetting throughout the day.

Integrating biological and behavioral factors in alcohol use risk: the role of ALDH2 status and alcohol expectancies in a sample of Asian Americans

Prior studies have shown that the ALDH2*2 genetic variant, most common in individuals of Asian descent, is related to heightened sensitivity to alcohol and can serve as a protective factor against alcohol problems. This study explored the effect of this factor on alcohol expectancies. It was hypothesized that (a) individuals with ALDH2*2 alleles would have lower positive expectancies and higher negative expectancies, (b) expectancies would mediate the ALDH2-drinking relation, and (c) ALDH2 status would moderate the expectancy-drinking relation. Data were collected from 171 Asian American university students. Positive expectancy and ALDH2 status were correlated with alcohol use. Mediation and moderation hypotheses were supported only in the female sample. Results were not significant for negative expectancies. These results indicate that ALDH2 status may protect against drinking by lowering positive expectancies and reducing the expectancy-drinking relationship.

Microdialysis assessment of shock wave lithotripsy-induced renal injury

OBJECTIVES

Shock wave lithotripsy (SWL) is the primary treatment modality for managing the majority of symptomatic renal calculi. However, the fundamental mechanisms for stone fragmentation and the resultant morphologic changes that occur are not fully understood. Furthermore, a thorough understanding of the complex biologic pathways involved in SWL-induced renal injury does not exist at present. To elucidate the biologic processes involved in tissue injury after SWL, an animal model was designed to mimic the pathogenesis of high-energy SWL in humans.

METHODS

Juvenile female swine were anesthetized, and a midline laparotomy incision was performed to expose the right kidney. Using an introducer apparatus, a microdialysis probe was placed into the renal parenchyma of the right kidney lower pole and a tunnel was generated to exit the distal ends of the inlet and outlet tubing outside the body. After a 72-hour postoperative recovery period, SWL was performed to the lower pole renal region of the kidney, as a microdialysis pump continuously infused dialysate through the inlet tubing. Microdialysis fluids were collected during SWL, and lipid peroxidation, as measured by conjugated diene concentrations, was monitored.

RESULTS

All microdialysis probes remained patent for a total of 2000 shock waves. A significant elevation in conjugated diene levels was observed in the SWL versus untreated kidneys after 1000 shock waves were administered (P <0.02).

CONCLUSIONS

This animal model is unique in that it represents the first system for the real-time collection of renal interstitial fluids during SWL. Analysis of this fluid may provide insight into the physiologic mechanisms responsible for shock wave-induced renal injury.

APC truncation and increased beta-catenin levels in a human breast cancer cell line

Mutations in the Adenomatous Polyposis Coli (APC) tumor suppressor gene or the beta-catenin gene are present in most colon cancers and less frequently in other tumor types. In this study, we screened 24 human breast cancer cell lines and three immortalized human breast epithelial cell lines for alterations in beta- and gamma-catenin and APC by western blotting, protein truncation assay and DNA sequence analysis. In one cell line (DU 4475), an APC mutation was identified (E1577stop) that resulted in expression of truncated APC. This mutation was associated with elevated cytosolic beta-catenin levels, probably due to loss of APC function, as in colon cancers. No mutations were found in exon 3 of the beta- or gamma-catenin genes. We conclude that APC mutations and beta-catenin upregulation may occur with low frequency in human breast cancer cells.

Rapid genetic diagnosis in neonatal pulmonary artery thrombosis caused by homozygous antithrombin Budapest 3

We report a case of spontaneous left pulmonary artery thrombosis in a 3-day-old male neonate. The presentation of heparin resistance and thrombosis raised the possibility of a type II heparin binding site antithrombin deficiency. A continuous infusion of antithrombin concentrate was used successfully, following failure of plasma, to correct the heparin resistance. Rapid genetic analysis allowed sequencing of the antithrombin gene within 5 working days. This showed the infant to be homozygous for the substitution of C to T at nucleotide 2759. This base change causes mutation of the native leucine at codon 99 to a phenylalanine. This antithrombin variant has been previously reported (antithrombin Budapest 3) and results in reduced binding of heparin to antithrombin. Such a molecular diagnostic approach is feasible and warranted in such cases of neonatal thrombosis because of the diagnostic difficulties encountered.

Ribozymes as tools for therapeutic target validation in arthritis

In this paper we describe a method for validating therapeutic gene targets in arthritic disease. Ribozymes are catalytic oligonucleotides capable of highly sequence-specific cleavage of RNA. We designed ribozymes that cleave the mRNA encoding stromelysin, a matrix metalloproteinase implicated in cartilage catabolism. Ribozymes were initially screened in cultured fibroblasts to identify sites in the mRNA that were accessible for binding and cleavage. Accessible sites for ribozyme binding were found in various regions of the mRNA, including the 5' untranslated region, the coding region, and the 3' untranslated region. Several ribozymes that mediated sequence-specific and dose-dependent inhibition of stromelysin expression were characterized. Site selection in cell culture was predictive of in vivo bioactivity. An assay for measuring cartilage catabolism in rabbit articular cartilage explants was developed. Ribozymes inhibited IL-1-stimulated stromelysin mRNA expression in articular cartilage explants, yet failed to inhibit proteoglycan degradation. This indicated that up-regulation of stromelysin was not essential for IL-1-induced cartilage catabolism. Broad applications of this approach in therapeutic target validation are discussed.

Substance dependence, family history of alcohol dependence and neuropsychological functioning in adolescence

AIMS

It was hypothesized that adolescent substance dependence moderates the relationship between family history of alcohol dependence and neuropsychological functioning.

DESIGN

This study compared the neuropsychological functioning of non-abusing and alcohol and drug-dependent adolescents with and without a family history of alcohol dependence using hierarchical multiple regressions and general factorial analyses.

SETTING

Substance-dependent adolescents were recruited and tested in inpatient alcohol and drug abuse treatment programs after 3 weeks of abstinence. A matched sample of non-abusing adolescents was recruited from the same San Diego-area communities.

PARTICIPANTS

Substance-dependent adolescents (n = 101) met DSM-III-R criteria for dependence on alcohol and at least one other substance. Non-abusing adolescents (n = 50) had no substance use disorders. Groups were comparable on socio-economic status. Participants were 44% female, ages 13-18, and had no serious head injuries or neurological disorders.

MEASUREMENTS

Information was gathered on demographics, family history, substance involvement, and conduct disorder behaviors and adolescents were administered neuropsychological tests covering language, visuospatial, verbal memory, attention and executive functioning domains.

FINDINGS

The hypothesis was supported for language and attention tests. Substance involvement interacted with family history of alcohol dependence to predict language and attention functioning. Family history negative non-abusers performed better than the other adolescents.

CONCLUSIONS

The pattern of results suggests that family history of alcohol dependence and adolescent substance use are separate risk factors for poorer neuropsychological performance in youth.