Insensitivity to pain induced by a potent selective closed-state Nav1.7 inhibitor.

Pain places a devastating burden on patients and society and current pain therapeutics exhibit limitations in efficacy, unwanted side effects and the potential for drug abuse and diversion. Although genetic evidence has clearly demonstrated that the voltage-gated sodium channel, Nav1.7, is critical to pain sensation in mammals, pharmacological inhibitors of Nav1.7 have not yet fully recapitulated the dramatic analgesia observed in Nav1.7-null subjects. Using the tarantula venom-peptide ProTX-II as a scaffold, we engineered a library of over 1500 venom-derived peptides and identified JNJ63955918 as a potent, highly selective, closed-state Nav1.7 blocking peptide. Here we show that JNJ63955918 induces a pharmacological insensitivity to pain that closely recapitulates key features of the Nav1.7-null phenotype seen in mice and humans. Our findings demonstrate that a high degree of selectivity, coupled with a closed-state dependent mechanism of action is required for strong efficacy and indicate that peptides such as JNJ63955918 and other suitably optimized Nav1.7 inhibitors may represent viable non-opioid alternatives for the pharmacological treatment of severe pain.

Use of computer assisted and interactive cognitive training programmes with moderate to severely demented individuals: a preliminary study.

The purpose of this study was to investigate the potential effects of interactive cognitive training and computer-assisted programmes in reducing decline in older adults with dementia. The primary goal of this programme was to maintain participants' level of cognitive function. This study included six moderately to severely demented older adults living in a secured memory-impairment unit within an assisted living community. The participants were assessed with neuropsychological tests prior to, and immediately following, an intensive six-week cognitive training programme. The results showed that the participants improved significantly on measures of overall cognitive function, including short-term memory and cognitive failures. Caregiver reports also indicated significant improvement in the participants' behaviour signs and socialization. Additionally, these participants did not demonstrate significant decline on any of the measures from pre-test to post-test levels. This preliminary study indicates that a combined interactive cognitive training and individual-based computer training programme may effectively reduce decline and even improve some cognitive and behavioural functioning in demented older adults. A follow-up of the participants after four weeks of no training revealed some decline in some of the cognitive and behavioural measures, thus supporting the effectiveness of the training programmes.

Patellofemoral joint kinematics in individuals with and without patellofemoral pain syndrome.

BACKGROUND: Patellofemoral pain syndrome is a prevalent condition in young people. While it is widely believed that abnormal patellar tracking plays a role in the development of patellofemoral pain syndrome, this link has not been established. The purpose of this cross-sectional case-control study was to test the hypothesis that patterns of patellar spin, tilt, and lateral translation make it possible to distinguish individuals with patellofemoral pain syndrome and clinical evidence of patellar malalignment from those with patellofemoral pain syndrome and no clinical evidence of malalignment and from individuals with no knee problems. METHODS: Three-dimensional patellofemoral joint kinematics in one knee of each of sixty volunteers (twenty in each group described above) were assessed with use of a new, validated magnetic resonance imaging-based method. Static low-resolution scans of the loaded knee were acquired at five different angles of knee flexion (ranging between -4 degrees and 60 degrees). High-resolution geometric models of the patella, femur, and tibia and associated coordinate axes were registered to the bone positions on the low-resolution scans to determine the patellar motion as a function of knee flexion angle. Hierarchical modeling was used to identify group differences in patterns of patellar spin, tilt, and lateral translation. RESULTS: No differences in the overall pattern of patellar motion were observed among groups (p>0.08 for all global maximum likelihood ratio tests). Features of patellar spin and tilt patterns varied greatly between subjects across all three groups, and no significant group differences were detected. At 19 degrees of knee flexion, the patellae in the group with patellofemoral pain and clinical evidence of malalignment were positioned an average of 2.25 mm more laterally than the patellae in the control group, and this difference was marginally significant (p=0.049). Other features of the pattern of lateral translation did not differ, and large overlaps in values were observed across all groups. CONCLUSIONS: It cannot be determined from our cross-sectional study whether the more lateral position of the patella in the group with clinical evidence of malalignment preceded or followed the onset of symptoms. It is clear from the data that an individual with patellofemoral pain syndrome cannot be distinguished from a control subject by examining patterns of spin, tilt, or lateral translation of the patella, even when clinical evidence of mechanical abnormality was observed.

Magnetic resonance imaging for in vivo assessment of three-dimensional patellar tracking.

We have developed a non-invasive measurement technique which can ultimately be used to quantify three-dimensional patellar kinematics of human subjects for a range of static positions of loaded flexion and assessed its accuracy. Knee models obtained by segmenting and reconstructing one high-resolution scan of the knee were registered to bone outlines obtained by segmenting fast, low-resolution scans of the knee in static loaded flexion. We compared patellar tracking measurements made using the new method to measurements made using Roentgen stereophotogrammetric analysis in three cadaver knee specimens loaded through a range of flexion in a test rig. The error in patellar spin and tilt measurements was less than 1.02 degrees and the error in lateral patellar shift was 0.88 mm. Sagittal plane scans provided more accurate final measurements of patellar spin and tilt, whereas axial plane scans provided more accurate measurements of lateral translation and patellar flexion. Halving the number of slices did not increase measurement error significantly, which suggests that scan times can be reduced without reducing accuracy significantly. The method is particularly useful for multiple measurements on the same subject because the high-resolution bone-models need only be created once; thus, the potential variability in coordinate axes assignment and model segmentation during subsequent measurements is removed.

Accurate assessment of patellar tracking using fiducial and intensity-based fluoroscopic techniques.

Accuracies of a point-based and an intensity-based fluoroscopic methods of assessing patella tracking were determined by comparing the pattern of patellar motion with respect to orientation (flexion, internal rotation, and lateral tilt) and translation (lateral, proximal, and anterior) with the pattern of patellar motion measured using Roentgen stereophotogrammetric analysis in three cadaver knee specimens. Each pose in the patellar motion could be obtained from single as well as multiple calibrated fluoroscopic images. The errors using the intensity-based method were slightly higher than those of the point-based method, but they appear to be sufficiently low to detect clinically significant differences in patellar kinematics.

Strabismus in premature infants in the first year of life. Cryotherapy for Retinopathy of Prematurity Cooperative Group.

OBJECTIVES: To present the 3- and 12-month strabismus data from 3030 premature infants with birth weights less than 1251 g enrolled in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity. DESIGN: Data from the 3- and 12-month examinations conducted at 23 regional study centers were tabulated for all infants. The main outcome measure, ocular motility, was compared with baseline demographic variables and retinopathy of prematurity severity for the worse eye. Findings at 3 months were compared with the incidence of strabismus at 12 months. RESULTS: At 3 months, 200 (6.6%) of the 3030 infants were strabismic. In the 2449 infants examined at both time points, 289 (11.8%) were found to have strabismus at 12 months. Retinopathy of prematurity was significant for strabismus at both 3 and 12 months (P<.001). The presence of strabismus at 3 months was found to be a highly significant predictor of strabismus at 12 months. Anisometropia, abnormal fixation, and unfavorable retinal structure also were significant predictors of strabismus at 1 year. The total prevalence of strabismus in the first year of life was 14.7%. CONCLUSION: The presence of acute-phase retinopathy of prematurity places the premature infant at increased risk for strabismus.

A comparison of cryotherapy versus diode laser retinopexy in 100 consecutive infants treated for threshold retinopathy of prematurity.

PURPOSE: The purpose of this paper is to present a series of patients who were treated for threshold retinopathy of prematurity with either cryotherapy or diode laser. Complications and unfavorable outcomes during the first year after treatment will be compared for the two procedures. METHODS: The clinical courses of a consecutive series of 100 infants (192 eyes) were reviewed. All infants had their threshold status confirmed by a second examiner. Infants were treated with cryotherapy through 1993 and with diode laser thereafter. One hundred two eyes of 54 patients were treated with cryotherapy. Ninety eyes of 46 patients were treated with laser retinopexy. Two of the patients who were treated with laser (4 eyes) did not survive to the 3-month follow-up visit, and their results are not included here. The two groups of infants were comparable in their birth weight, adjusted gestational age at treatment, and severity of disease as determined by zone and sectors of stage 3 retinopathy of prematurity. RESULTS: Unfavorable outcome (total retinal detachment) was seen in 25.4% of eyes treated with cryotherapy (26 of 102), as compared with 15% of eyes treated with laser (13 of 86). Two cataracts were seen in our patients: one patient 22 weeks after cryotherapy, and the other 7 months after diode laser. CONCLUSIONS: No statistically significant difference was found in the rate of retinal detachments in the two groups (X2 = 3.05; P = .08).

Retinopathy of prematurity in discordant twins.

Discordant twins may be at increased risk for retinopathy of prematurity (ROP) because of factors related to their unequal growth. Discordancy is defined as a difference of 15% or more in the birth weights of the two infants. We examined the data in 26 sets of discordant twins from six NICUs, including birthweight, gestational age, sex, and highest grade of ROP. Thirty-eight percent (10) of the lower birthweight infants had higher grades of ROP than their twin. Twenty-three percent (6) of the heavier birthweight twins had higher grades of ROP than their smaller siblings. Three infants reached threshold, and five were prethreshold. In every case, their twin siblings had mild or no ROP. Thirty-eight percent of the twins (10) had the same ROP outcome.

Diagnosis of gastroesophageal reflux in pediatrics.

Gastroesophageal reflux (GER) may be normal, functional, or pathogenic. Normal GER is of short duration and seen in all individuals. Functional GER, or effortless regurgitation, is common during infancy, causing no ill effects. Pathogenic GER causes diseases such as failure-to-thrive, coughing, choking, aspiration, apnea and/or bradycardia, esophagitis with irritability and excessive crying. Clinically it becomes imperative to distinguish normal and functional from pathogenic GER. The tests presently employed to detect GER are roentgenogram of the upper gastrointestinal tract (showing barium GER), scintigraphy of the esophagus after ingestion of a 99mTc labeled meal (indicating meal GER) and prolonged pH probe monitoring the lower esophagus (depicting acid GER). There seems to be a controversy regarding the usefulness of these tests for the diagnosis of pathogenic GER. In the present study of 89 infants and children presenting with signs and symptoms of pathogenic GER, 70% had significant acid GER, while 36% and 17% had barium and meal GER respectively. No statistically significant correlations were detected between acid GER, barium GER, and meal GER. We conclude that these three tests probably represent different phenomena, and that prolonged esophageal pH monitoring should be considered the most reliable and gold standard for detection of pathogenic GER.

Michel's anomaly, type I microtia and microdontia.

Michel's anomaly is an extremely rare cause of congenital sensorineural hearing loss. We present a 2-1/2 year old white female with this inner ear defect associated with type I microtia and microdontia. Assessment of anatomic structures of the ear is critical in an infant with abnormal auditory brainstem responses to determine whether a structural lesion is present and the most appropriate rehabilitative approach available.

Fetal development and neuronal/glial cell specificity of cAMP-dependent protein kinase subunit mRNAs in rat brain.

All known actions of cAMP in the brain require cAMP-dependent protein kinase (cAMPdPK), which consists of regulatory (R) and catalytic (C) subunits (R2C2). Using homologous rat cDNAs for all known cAMPdPK subunit isoforms found in the brain (RI alpha, RI beta, RII alpha, RII beta, C alpha, C beta) we observe that, in the fetal rat brain from 12 days of gestation to birth, while alpha subunit (RI alpha, RII alpha, C alpha) mRNA levels are abundant, beta subunit (RI beta, RII beta, C beta) mRNA levels increase from undetectable or very low levels to abundant levels. Furthermore, while alpha subunit mRNA levels are abundant in both primary neuronal and primary glial cultures, beta subunit mRNA levels are very low (C beta) or undetectable (RI beta, RII beta) in primary glial cultures, but are abundant in primary neuronal cultures. Thus, prior to about 12 days of gestation, cAMP in the brain may act only via the alpha cAMPdPK subunits in neuronal and glial precursor cells. After 12 days of gestation, coincident with the onset of final cell division in neurons, beta cAMPdPK subunits may also mediate the effects of cAMP predominantly in neurons.

Rat RI beta isoform of type I regulatory subunit of cyclic adenosine monophosphate-dependent protein kinase: cDNA sequence analysis, mRNA tissue specificity, and rat/mouse difference in expression in testis.

A rat complementary DNA (cDNA) for the RI beta isoform of type I cyclic adenosine monophosphate (cAMP)-dependent protein kinase regulatory subunit was cloned and sequenced and was found to contain the entire protein coding and 3'-untranslated regions, with a single (ATTAAA) poly-adenylation site. The largest open reading frame was preceded by a short out-of-phase open reading frame, which is not seen in the corresponding mouse RI beta cDNA due to a single base substitution. The rat RI beta cDNA clone was 2,374 bases long and detected a rat mRNA of approximately 2.8 kilobases. Rat RI beta mRNA was abundant in adult rat brain and testis but was undetectable in other rat tissues. The rat RI beta cDNA also detected RI beta mRNA in mouse brain, but not mouse testis, from 10-week-old BALB/c or 10- and 6-week-old Swiss Webster mice. Thus, despite a 96% nucleotide identity in the coding region of RI beta in rat vs. mouse, there are at least two differences in these closely related species. First, there is a short open reading frame, which precedes the coding region in the rat but not the mouse. Second, unlike the mouse testis, the rat testis contains abundant levels of RI beta mRNA.

Comparative metabolic behavior and interrelationships of Tc and S in soybean plants.

The comparative behavior of sulfur (S) and technetium (Tc) in soybean seedlings shows gross subcellular distributions to be similar for these oxyanions. More than 75% of the tissue-deposited Tc remains soluble and extractable. Differences in Tc fixation/incorporation were noted for the nuclear and chloroplast fractions of leaf and root cells. Pulse studies showed that soluble protein and nitrate reductase levels rose in response to Tc accumulation by sink leaves but not source leaves. In vitro assay of chloroplast-based S reduction and incorporation systems showed Tc to be reduced and incorporated into amino nitrogen-containing products. A hypothesis related to the metabolic behavior of Tc in plants is presented.

Glucose-dependent regulation of glucose transport activity, protein, and mRNA in primary cultures of rat brain glial cells.

D-Glucose deprivation of primary rat brain glial cell cultures, by incubation with 25 mM D-fructose for 24 h, resulted in a 4-5-fold induction of D-glucose transport activity. In contrast, 24-h D-glucose starvation of primary rat brain neuronal cultures had only a marginal effect (1.5-2-fold) on D-glucose transport activity. Northern blot analysis of total cellular RNA demonstrated that under these conditions the rat brain glial cells specifically increased the steady-state level of the D-glucose transporter mRNA 4-6-fold, whereas Northern blot analysis of the neuronal cell cultures revealed no significant alteration in the amount of D-glucose transporter mRNA by D-glucose deprivation. These findings demonstrated that the D-glucose-dependent regulation of the D-glucose transporter system occurred in a brain cell type-specific manner. The ED50 for the D-glucose starvation increase in the D-glucose transporter mRNA, in the glial cell cultures, occurred at approximately 3.5 mM D-glucose with maximal effect at 0.5 mM D-glucose. Readdition of D-glucose to the starved cell cultures reversed the increase in the D-glucose transporter mRNA levels and D-glucose transport activity to control values within 24 h. The increase in the D-glucose transporter mRNA was relatively rapid with half-maximal stimulation at approximately 2 h and maximal induction by 6-12 h of D-glucose deprivation. A similar time course was also observed for the starvation-induced increase in D-glucose transport activity and D-glucose transporter protein, as determined by Western blot analysis. These results document that, in rat brain glial cells, D-glucose transport activity, protein, and mRNA are regulated by the extracellular D-glucose concentration. Further, this suggests a potential role for hyperglycemia in the down-regulation of the D-glucose transport system in vivo.

Identification of an insulin-like factor in astrocyte conditioned medium.

Survival of dissociated 19-day fetal rat telencephalic neurons in a hormone-free defined medium required the addition of insulin at pharmacological concentrations. However, survival of astrocytes cultured from the cerebral cortex of newborn rats in the same medium did not require insulin. When fetal neurons were incubated with astrocyte conditioned medium or plated on a monolayer of astrocytes, their survival was significantly increased in the absence of insulin. This effect of astrocyte conditioned medium was visibly inhibited by affinity chromatography on an anti-insulin protein A agarose column. A 5-30 kDa ultrafiltration fraction of astrocyte conditioned medium also increased neuronal survival. In addition, the 5-30 kDa fraction stimulated [3H]leucine incorporation into the TCA insoluble material from cultured neurons and competed for [125I]insulin binding to intact neuronal cultures. These results indicate that cultured astrocytes produce a factor with biological and immunological properties similar to those of insulin. This factor may in part mediate the observed neurotrophic effects of astrocyte conditioned medium and may play a role in the normal development and differentiation of central nervous system neurons.