A targeted chain-termination mutation in the mouse Apc gene results in multiple intestinal tumors

Germ-line mutations in the human adenomatous polyposis coli (APC) gene result in familial adenomatous polyposis, an autosomal dominant disorder characterized by the early onset of multiple adenomatous polyps in the large bowel with a high likelihood of developing colorectal carcinomas. To understand the role of APC in intestinal tumor formation, we have introduced a chain-termination mutation in the 15th exon of the mouse Apc gene and employed it to modify the endogenous gene by homologous recombination in embryonic stem cells. Mice which are heterozygous for the Apc gene modification progressively develop intestinal tumors in a manner that is similar to that observed in patients with familial adenomatous polyposis and in mice which carry a mutation called multiple intestinal neoplasia (Min). Our results indicate that the Apc gene modification is a critical event in the initiation of intestinal tumor formation and results in an autosomal dominant predisposition toward development of spontaneous colonic and intestinal tumors in mice.

Molecular definition of 22q11 deletions in 151 velo-cardio-facial syndrome patients

Velo-cardio-facial syndrome (VCFS) is a relatively common developmental disorder characterized by craniofacial anomalies and conotruncal heart defects. Many VCFS patients have hemizygous deletions for a part of 22q11, suggesting that haploinsufficiency in this region is responsible for its etiology. Because most cases of VCFS are sporadic, portions of 22q11 may be prone to rearrangement. To understand the molecular basis for chromosomal deletions, we defined the extent of the deletion, by genotyping 151 VCFS patients and performing haplotype analysis on 105, using 15 consecutive polymorphic markers in 22q11. We found that 83% had a deletion and >90% of these had a similar approximately 3 Mb deletion, suggesting that sequences flanking the common breakpoints are susceptible to rearrangement. We found no correlation between the presence or size of the deletion and the phenotype. To further define the chromosomal breakpoints among the VCFS patients, we developed somatic hybrid cell lines from a set of VCFS patients. An 11-kb resolution physical map of a 1,080-kb region that includes deletion breakpoints was constructed, incorporating genes and expressed sequence tags (ESTs) isolated by the hybridization selection method. The ordered markers were used to examine the two separated copies of chromosome 22 in the somatic hybrid cell lines. In some cases, we were able to map the chromosome breakpoints within a single cosmid. A 480-kb critical region for VCFS has been delineated, including the genes for GSCL, CTP, CLTD, HIRA, and TMVCF, as well as a number of novel ordered ESTs.

Attention deficit/hyperactivity disorder children with a 7-repeat allele of the dopamine receptor D4 gene have extreme behavior but normal performance on critical neuropsychological tests of attention

An association of the dopamine receptor D4 (DRD4) gene located on chromosome 11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated and replicated by multiple investigators. A specific allele [the 7-repeat of a 48-bp variable number of tandem repeats (VNTR) in exon 3] has been proposed as an etiological factor in attentional deficits manifested in some children diagnosed with this disorder. In the current study, we evaluated ADHD subgroups defined by the presence or absence of the 7-repeat allele of the DRD4 gene, using neuropsychological tests with reaction time measures designed to probe attentional networks with neuroanatomical foci in D4-rich brain regions. Despite the same severity of symptoms on parent and teacher ratings for the ADHD subgroups, the average reaction times of the 7-present subgroup showed normal speed and variability of response whereas the average reaction times of the 7-absent subgroup showed the expected abnormalities (slow and variable responses). This was opposite the primary prediction of the study. The 7-present subgroup seemed to be free of some of the neuropsychological abnormalities thought to characterize ADHD.

Increased transcription levels induce higher mutation rates in a hypermutating cell line

Somatic hypermutation, in addition to V(D)J recombination, is the other major mechanism that generates the vast diversity of the Ab repertoire. Point mutations are introduced in the variable region of the Ig genes at a million-fold higher rate than in the rest of the genome. We have used a green fluorescent protein (GFP)-based reversion assay to determine the role of transcription in the mutation mechanism of the hypermutating cell line 18-81. A GFP transgene containing a premature stop codon is transcribed from the inducible tet-on operon. Using the inducible promoter enables us to study the mutability of the GFP transgene at different transcription levels. By analyzing stable transfectants of a hypermutating cell line with flow cytometry, the mutation rate at the premature stop codon can be measured by the appearance of GFP-positive revertant cells. Here we show that the mutation rate of the GFP transgene correlates with its transcription level. Increased transcription levels of the GFP transgene caused an increased point mutation rate at the premature stop codon. Treating a hypermutating transfection clone with trichostatin A, a specific inhibitor of histone deacetylase, caused an additional 2-fold increase in the mutation rate. Finally, using Northern blot analysis we show that the activation-induced cytidine deaminase, an essential trans-factor for the in vivo hypermutation mechanism, is transcribed in the hypermutating cell line 18-81.

Effects of attentional focus, self-control, and dyad training on motor learning: implications for physical rehabilitation

In this article, the authors review recent studies on 3 factors that have been shown to affect the learning of motor skills-the performer's attentional focus, self-control, and practice in dyads-and discuss their implications for rehabilitation. Research has shown that directing learners' attention to the effects of their movements can be more beneficial for learning than directing their attention to the details of their own actions. Furthermore, giving learners some control over the training regimen has been found to enhance learning, unlike prescriptive training protocols that dictate when feedback will be delivered, how often, and the order that tasks will be practiced. Finally, not only can practice in dyads (or larger groups) reduce the costs of training, but it can also result in more effective learning than individual practice sessions. The incorporation of these factors into rehabilitation practice can potentially enhance the effectiveness and efficiency of rehabilitation.

Velo-cardio-facial syndrome: frequency and extent of 22q11 deletions

Velo-cardio-facial (VCFS) or Shprintzen syndrome is associated with deletions in a region of chromosome 22q11.2 also deleted in DiGeorge anomaly and some forms of congenital heart disease. Due to the variability of phenotype, the evaluation of the incidence of deletions has been hampered by uncertainty of diagnosis. In this study, 54 patients were diagnosed with VCFS by a single group of clinicians using homogeneous clinical criteria independent of the deletion status. Cell lines of these patients were established and the deletion status evaluated for three loci within the commonly deleted region at 22q11.2 using fluorescence in situ hybridization (FISH). In 81% of the patients all three loci were hemizygous. In one patient we observed a smaller interstitial deletion than that defined by the three loci. The phenotype of this patient was not different from that observed in patients with larger deletions.

Comparative analysis of human DNA variations by fluorescence-based sequencing of PCR products

Automated, direct cycle sequencing of purified double-stranded PCR products using Taq polymerase and fluorescently labeled dideoxynucleotide terminators provides a robust and highly reproducible method for identifying DNA sequence variations in sequence-tagged sites. We describe a simple and sensitive strategy that reliably detects the presence of DNA variations when sequencing traces from several different individuals are compared. We also demonstrate the use of this strategy to estimate allele frequencies of single nucleotide substitutions in a population. Taken together, this approach provides an automated method for conducting rapid population studies of candidate gene regions that are in linkage or association with a specific disease and for comparative evolutionary analysis of selected regions of the human genome.

A physical, chemical, and mechanical study of lumbar vertebrae from normal, ovariectomized, and nandrolone decanoate-treated cynomolgus monkeys (Macaca fascicularis)

Ovariectomized cynomolgus monkeys have previously been investigated as a nonhuman primate model of postmenopausal osteoporosis (Jerome et al., Bone Miner 9:527-540; 1994). In the present study, Fourier transform infrared microspectroscopy (FTIRM) was used to verify that differences in bone mineral quality and quantity in the vertebrae of mature intact (INT) and ovariectomized (ovx) monkeys were analogous to those seen in osteoporotic and nondiseased human bones. FTIRM spectra were acquired from 15 trabeculae per vertebra from three ovx and three INT adult monkeys (mean age 8 years). These spectra were compared with those of both trabecular and previously reported osteonal bone obtained from 3 "normal" and 11 postmenopausal osteoporotic human subjects. While variations in the mineral:matrix ratio (mineral content), carbonate:phosphate ratio, and crystallinity are typical for trabecular bone from iliac crests of normal human subjects, the values of these parameters were relatively static for trabecular bone from postmenopausal osteoporotic human subjects. In general, trabecular bone from postmenopausal osteoporotic human subjects exhibited decreased mineral content (1.0 +/- 0.5 vs. 2.9 +/- 0.6), increased crystallinity, and increased carbonate:phosphate relative to controls. Similarly, trabecular bone from ovariectomized monkeys exhibited lower mineral content (5.8 +/- 0.2) compared with the INT group (6.2 +/- 0.2; p </= 0.05) and contained larger/more perfect apatite crystals (increased crystallinity) with increased carbonate:phosphate ratios. Variations in absolute values were attributable to site differences (ilium vs. vertebrae). To appreciate the importance of mineral properties on mechanical properties, compression testing was performed using cores of monkey L-3 and L-4 vertebral bodies from a separate group of monkeys. Treating monkeys with the anabolic steroid nandrolone decanoate (ND) immediately after ovariectomy and for the next 24 months (ND group), or beginning 12 months after ovariectomy (dND group), increased the ultimate stress compared with an ovx treatment group, despite large interanimal variations in bone architecture and mechanical properties. These data support the hypothesis that ovariectomized adult monkeys are an excellent model for postmenopausal osteoporosis, and can be used for the evaluation of therapeutic modalities.

Taxol content in bark, wood, root, leaf, twig, and seedling from several Taxus species

Taxol content in various parts of several Taxus species have been determined. The weight percent ranged from 0.00003 to 0.069.

Molecular model of the interaction between the glucocorticoid receptor and the regulatory elements of inducible genes

Binding sites for the glucocorticoid receptor in an ecdysone-inducible gene from Drosophila melanogaster and in the chicken vitellogenin gene are described. A comparison with other binding sites for the glucocorticoid receptor, which have been analyzed by methylation protection experiments, shows they can be classified into three groups. The first group exhibits two blocks of contact points in two subsequent turns of the DNA helix, and includes only functional regulatory elements. The second group shows an identical contact with the hexanucleotide 5'-TGTYCT-3', but only half the contact points in the other turn of the helix, whereas the third group of sites exhibits only the contact points within the conserved hexanucleotide. An analysis of the hydrogen-bonding potential of the DNA base pairs along the major groove of 10 binding sites shows a very well-conserved pattern and a twofold rotational symmetry, suggesting that the array of hydrogen bonds may be a relevant aspect of sequence recognition by hormone receptors. A representation of the binding sites and contact points by computer graphics suggests the interaction of a receptor dimer, in a head-to-head arrangement, with two subsequent turns of the B-DNA helix within the glucocorticoid regulatory elements.

The Texas Children's Medication Algorithm Project: Report of the Texas Consensus Conference Panel on Medication Treatment of Childhood Attention-Deficit/Hyperactivity Disorder. Part I. Attention-Deficit/Hyperactivity Disorder

OBJECTIVES

Expert consensus methodology was used to develop evidence-based, consensually agreed-upon medication treatment algorithms for attention-deficit/hyperactivity disorder (ADHD) in the public mental health sector. Although treatment algorithms for adult mental disorders have been developed, this represents one of the first attempts to develop similar algorithms for childhood mental disorders. Although these algorithms were developed initially for the public sector, the goals of this approach are to increase the uniformity of treatment and improve the clinical outcomes of children and adolescents with ADHD in a variety of treatment settings.

METHOD

A consensus conference of academic clinicians and researchers, practicing clinicians, administrators, consumers, and families was convened to develop evidence-based consensus algorithms for the pharmacotherapy of childhood ADHD. After a series of presentations of current research evidence and panel discussion, the consensus panel met and drafted the algorithms along with guidelines for implementation.

RESULTS

The panel developed consensually agreed-upon algorithms for ADHD with and without specific comorbid disorders. The algorithms consist of systematic strategies for psychopharmacological interventions and tactics to ensure successful implementation of the strategies. While the algorithms focused on the medication management of ADHD, the conference emphasized that psychosocial treatments are often a critical component of the overall management of ADHD.

CONCLUSIONS

Medication algorithms for ADHD can be developed with consensus. A companion article will discuss the implementation of these algorithms.

Clinical effectiveness and cost analysis of patient referral by videoconferencing in orthopaedics

The clinical effectiveness and costs of videoconferencing in orthopaedics between primary and secondary care were examined in an eight-month prospective, comparative study. The general surgery outpatient clinics of two Finnish district hospitals were compared: Peijas Hospital, with telemedicine, and Hyvinkää Hospital, without it. The three study primary-care centres referred a total of 419 adult patients to the outpatient clinics. The population-based number of referrals to Peijas Hospital was similar to that to Hyvinkää Hospital after adjusting for the proportion of older people living in the Hyvinkää Hospital municipalities. Of the 225 patients referred to Peijas Hospital, 168 (75%) were given appointments at the outpatient clinic of surgery and the rest of the referred patients received a teleconsultation. All patients referred to Hyvinkää Hospital were given appointments at the outpatient clinic. The direct costs of an outpatient visit were 45% greater per patient than for a teleconsultation, with a marginal cost decrease of EU48 for every new teleconsultation. A cost-minimization analysis of the alternative interventions showed a net benefit of EU2500 in favour of teleconsultations. The use of videoconferencing between primary and secondary care was modest in orthopaedics, although the use of this telemedicine method was shown to reduce direct costs and be cost-effective.

Registered Replication Report: Schooler and Engstler-Schooler (1990)

Trying to remember something now typically improves your ability to remember it later. However, after watching a video of a simulated bank robbery, participants who verbally described the robber were 25% worse at identifying the robber in a lineup than were participants who instead listed U.S. states and capitals-this has been termed the "verbal overshadowing" effect (Schooler & Engstler-Schooler, 1990). More recent studies suggested that this effect might be substantially smaller than first reported. Given uncertainty about the effect size, the influence of this finding in the memory literature, and its practical importance for police procedures, we conducted two collections of preregistered direct replications (RRR1 and RRR2) that differed only in the order of the description task and a filler task. In RRR1, when the description task immediately followed the robbery, participants who provided a description were 4% less likely to select the robber than were those in the control condition. In RRR2, when the description was delayed by 20 min, they were 16% less likely to select the robber. These findings reveal a robust verbal overshadowing effect that is strongly influenced by the relative timing of the tasks. The discussion considers further implications of these replications for our understanding of verbal overshadowing.

Serious renal impairment is associated with long-term parenteral nutrition

Thirty-three current long-term total parenteral nutrition (TPN) patients (13 men, 20 women) aged 21 to 79 years were prospectively studied to evaluate their change in glomerular filtration rate since beginning TPN. Creatinine clearance (CrCl) from the subject's initial home TPN clinic visit and at present were estimated from standard formulas and compared. The CrCl in 12 patients who had received home TPN for > 10 years was estimated retrospectively on a yearly basis. The estimated CrCl as an accurate measure of glomerular filtration rate was confirmed by measuring plasma indium-111 diethylenetriamine pentaacetic acid clearance. The mean daily intravenous protein intake and days during which nephrotoxic medications were used and number of bacteremic/fungemic episodes were determined for each subject. CrCl declined by 3.5 +/- 6.3% per year (p = .004). Twenty-nine of 33 patients had decreases of 0.6% to 15.4% per year. Tubular function, as determined by the tubular reabsorption of phosphate, was impaired in 52% of the subjects. The intravenous protein load averaged 1.28 +/- 0.32 g/kg per day, nephrotoxic drug use averaged 3.4 +/- 4.0% of all days on home TPN, and each patient averaged 2.3 episodes of bacteremia or fungemia since home TPN was started (0.5 +/- 0.5 episodes per year). When all factors were assessed simultaneously, nephrotoxic drug use, episodes of bacteremia/fungemia, and age accounted for approximately 46% of the variability in CrCl. When bacteremia/fungemia was expressed as a yearly rate, nephrotoxic drug use assumed no role in the glomerular filtration rate determination; infection rate and age alone accounted for 53% of the CrCl variability. We describe a profound decrease in renal function associated with long-term TPN, most of which is largely unexplained.

Brainstem auditory evoked potentials in postconcussion dizziness

Twenty-seven patients with postconcussion dizziness following minor injury to the head or neck had brainstem auditory evoked potential studies from one day to eight months (median, 37 days) following injury. All patients were normal on clinical examination at the time of study. Three patients had one or more interpeak latencies prolonged beyond the 99% tolerance limit for normal control subjects. The group mean 1-3, 2-3, and 1-5 interpeak latencies were significantly prolonged. These findings indicate that minor head or neck injury with associated subjective symptomatology may be accompanied by objectively demonstrable brainstem dysfunction.

An examination of the "dosage" effects of both behavior therapy and methylphenidate on the classroom performance of two ADHD children

Within the context of two case studies, the effects of two doses of methylphenidate (MPH) and behavioral interventions of varying potency are examined independently and jointly. Whereas studies of dose effects of MPH exist in the current literature, studies of different "doses" of behavior therapy-that is, interventions that vary in potency--are rare. This article uses a within-subjects design to demonstrate the importance of examining different doses of both types of treatments in determining the maximally effective treatment for a given child. The importance of considering individual differences is emphasized throughout this article as response to treatment among Attention-Deficit Hyperactivity Disorder children is quite variable. Case 1 illustrates the importance of evaluating medication response within the context of differing doses of behavior therapy; Case 2 demonstrates that difficult-to-manage cases are sometimes manageable using potent doses of both treatments simultaneously.

The cerebral metabolic ratio is not affected by oxygen availability during maximal exercise in humans

Intense exercise decreases the cerebral metabolic ratio of O(2) to carbohydrates (glucose + (1/2) lactate) and the cerebral lactate uptake depends on its arterial concentration, but whether these variables are influenced by O(2) availability is not known. In six males, maximal ergometer rowing increased the arterial lactate to 21.4 +/- 0.8 mm (mean +/- s.e.m.) and arterial-jugular venous (a-v) difference from -0.03 +/- 0.01 mm at rest to 2.52 +/- 0.03 mm (P < 0.05). Arterial glucose was raised to 8.5 +/- 0.5 mm and its a-v difference increased from 1.03 +/- 0.01 to 1.86 +/- 0.02 mm (P < 0.05) in the immediate recovery. During exercise, the cerebral metabolic ratio decreased from 5.67 +/- 0.52 at rest to 1.70 +/- 0.23 (P < 0.05) and remained low in the early recovery. Arterial haemoglobin O(2) saturation was 92.5 +/- 0.2% during exercise with room air, and it reached 87.6 +/- 1.0% and 98.9 +/- 0.2% during exercise with an inspired O(2) fraction of 0.17 and 0.30, respectively. Whilst the increase in a-v lactate difference was attenuated by manipulation of cerebral O(2) availability, the cerebral metabolic ratio was not affected significantly. During maximal rowing, the cerebral metabolic ratio reaches the lowest value with no effect by a moderate change in the arterial O(2) content. These findings suggest that intense whole body exercise is associated with marked imbalance in the cerebral metabolic substrate preferences independent of oxygen availability.

Acute cytomegalovirus infection complicated by vascular thrombosis: a case report

We present a case report of a previously healthy adult with cytomegalovirus infection that was complicated by extensive mesenteric arterial and venous thrombosis. To our knowledge, this is the first reported case of this syndrome in an immunocompetent individual who had no predisposing risk factors for thrombosis, and it demonstrates the propensity for cytomegalovirus to be involved in vascular disease.

The relationship of the nonstress test to gestational age

Five hundred ninety-three nonstress tests were performed on 41 obstetric patients, at gestational ages ranging from 20 to 40 weeks. Diagnoses included 10 cases of prematurity, six cases of diabetes mellitus, five cases of collagen-vascular disease, five cases of poor obstetric history, three cases of cardiac arrhythmia, and one case each of asthma, polyhydramnios, leukemia, nonimmune fetal hydrops; and eight volunteers were without high-risk factors. All neonates had a 5-minute Apgar score greater than 8; 29 neonates weighed greater than or equal to 2500 gm, 12 weighed less than 2500 gm, and four weighed less than 1500 gm. One neonate died of prematurity, and one was small for gestational age. There were no congenital anomalies. There was a significant difference in the number of reactive nonstress tests and nonreactive nonstress tests between the 20- to 24-week, 24- to 28-week, 28- to 32-week, and 32- to 36-week gestational age groups. The increased incidence of nonreactive nonstress tests at earlier gestational ages may have clinical implications.

Patient referral by telemedicine: effectiveness and cost analysis of an Intranet system

The clinical effectiveness and costs of telemedicine in improving the referral process from primary to secondary care were examined in an eight-month prospective, comparative study with one-year follow-up. The internal-medicine outpatient clinics of two Finnish district hospitals were compared--Peijas Hospital (PH) with telemedicine and Hyvinkää Hospital (HH) without it. The three primary-care centres studied referred a total of 292 adult patients to the outpatient clinics. The population-based number of referrals to PH (7.5/1000) from primary-care centres was twice that to HH (3.8/1000). Thirty-seven per cent of referrals to PH included requests from general practitioners for on-line medical advice (teleconsultation). Forty-three per cent of the total number of intranet referrals resulted in outpatient visits at PH, compared with 79% in the outpatient clinic at HH. Only 18% of the patients receiving a teleconsultation ended up in the outpatient department of PH within one year. These visits were mainly due to progression of chronic disease. No deaths or missed diagnoses could be attributed to telemedicine, but one diagnosis was delayed. The direct costs of an outpatient clinic visit in internal medicine (EU211) were seven times greater per patient than for an e-mail consultation (EU32), with a marginal cost decrease of EU179 for every new intranet consultation. A cost-minimization analysis of the alternative interventions showed a net benefit of EU7876 in favour of the teleconsultation process. General practitioners sought an outpatient visit for 130 of their patients, and advice only for another 77. On-line advice was nonetheless given in 108 cases, and only 88 patient visits were arranged. Eleven referrals were declined. The cost difference between giving on-line medical advice for the 108 cases and a visit to the outpatient clinic for the other 88 was less costly (by EU4140) than investigating the 124 patients whose original clinic referrals to the PH were not declined. Productivity in the hospital increased over threefold by using e-mail consultations instead of traditional outpatient visits. The wide interactive use of the intranet referral system between secondary and primary care improved clinical effectiveness, lowered direct costs, increased productivity and was cost-effective.

The Texas Children's Medication Algorithm Project: Report of the Texas Consensus Conference Panel on Medication Treatment of Childhood Attention-Deficit/Hyperactivity Disorder. Part II: Tactics. Attention-Deficit/Hyperactivity Disorder

OBJECTIVES

Expert consensus methodology was used to develop a medication treatment algorithm for attention-deficit/hyperactivity disorder (ADHD). The algorithm broadly outlined the choice of medication for ADHD and some of its most common comorbid conditions. Specific tactical recommendations were developed with regard to medication dosage, assessment of drug response, management of side effects, and long-term medication management.

METHOD

The consensus conference of academic clinicians and researchers, practicing clinicians, administrators, consumers, and families developed evidence-based tactics for the pharmacotherapy of childhood ADHD and its common comorbid disorders. The panel discussed specifics of treatment of ADHD and its comorbid conditions with stimulants, antidepressants, mood stabilizers, alpha-agonists, and (when appropriate) antipsychotics.

RESULTS

Specific tactics for the use of each of the above agents are outlined. The tactics are designed to be practical for implementation in the public mental health sector, but they may have utility in many practice settings, including the private practice environment.

CONCLUSIONS

Tactics for psychopharmacological management of ADHD can be developed with consensus.

Anti-tumor immune response correlates with neurological symptoms in a dog with spontaneous astrocytoma treated by gene and vaccine therapy

Gene therapy and vaccination have been tested in malignant glioma patients with modest, albeit encouraging results. The combination of these therapies has demonstrated synergistic efficacy in murine models but has not been reported in large animals. Gemistocytic astrocytoma (GemA) is a low-grade glioma that typically progresses to lethal malignancy despite conventional therapies. Until now there has been no useful animal model of GemA. Here we report the treatment of a dog with spontaneous GemA using the combination of surgery, intracavitary adenoviral interferon gamma (IFNgamma) gene transfer, and vaccination with glioma cell lysates mixed with CpG oligodeoxynucleotides. Surgical tumor debulking and delivery of Ad-IFNgamma into the resection cavity were performed. Autologous tumor cells grew slowly in culture, necessitating vaccination with allogeneic tumor lysate in four of the five vaccinations. Transient left-sided blindness and hemiparesis occurred following the fourth and fifth vaccinations. These neurological symptoms correlated with a peak in the levels of tumor-reactive IgG and CD8(+) T cells measured in the blood. All symptoms resolved and this dog remains tumor-free over 450 days following surgery. This case report preliminarily demonstrates the feasibility of treating dogs with spontaneous glioma using immune-based therapy and warrants further study using this therapeutic approach.