Development of the mouse inner ear and origin of its sensory organs

The molecular mechanisms dictating the morphogenesis and differentiation of the mammalian inner ear are largely unknown. To better elucidate the normal development of this organ, two approaches were taken. First, the membranous labyrinths of mouse inner ears ranging from 10.25 to 17 d postcoitum (dpc) were filled with paint to reveal their gross development. Particular attention was focused on the developing utricle, saccule, and cochlea. Second, we used bone morphogenetic protein 4 (BMP4) and lunatic fringe (Fng) as molecular markers to identify the origin of the sensory structures. Our data showed that BMP4 was an early marker for the superior, lateral, and posterior cristae, whereas Fng served as an early marker for the macula utriculi, macula sacculi, and the sensory portion of the cochlea. The posterior crista was the first organ to appear at 11.5 dpc and was followed by the superior crista, the lateral crista, and the macula utriculi at 12 dpc. The macula sacculi and the cochlea were present at 12 dpc but became distinguishable from each other by 13 dpc. Based on the gene expression patterns, the anterior and lateral cristae may share a common origin. Similarly, three sensory organs, the macula utriculi, macula sacculi, and cochlea, seem to arise from a single region of the otocyst.

A poxvirus-encoded semaphorin induces cytokine production from monocytes and binds to a novel cellular semaphorin receptor, VESPR

The vaccinia virus A39R protein is a member of the semaphorin family. A39R.Fc protein was used to affinity purify an A39R receptor from a human B cell line. Tandem mass spectrometry of receptor peptides yielded partial amino acid sequences that allowed the identification of corresponding cDNA clones. Sequence analysis of this receptor indicated that it is a novel member of the plexin family and identified a semaphorin-like domain within this family, thus suggesting an evolutionary relationship between receptor and ligand. A39R up-regulated ICAM-1 on, and induced cytokine production from, human monocytes. These data, then, describe a receptor for an immunologically active semaphorin and suggest that it may serve as a prototype for other plexin-semaphorin binding pairs.

Gender differences in knee injury epidemiology among competitive alpine ski racers

A questionnaire was sent in 1995 to all members of the Vermont Alpine Racing Association and several New England NCAA Division I ski racing programs. A total of 1010 surveys were sent and 404 responses were received. The survey included questions regarding the racer's age, gender, number of years spent ski racing, injury to knee(s), surgery to knee(s), and reinjury to a surgically reconstructed anterior cruciate ligament (ACL) requiring subsequent surgery. Only injuries that occurred during alpine skiing were included. One-quarter of respondents (27%) reported a history of a knee injury. Female racers were 2.3 times more likely to have sustained a knee injury than male racers. More impressively, one in five female alpine racers (22%) reported an ACL disruption, and females were 3.1 times more likely to sustain an ACL injury in comparison to their male counterparts. Of the athletes who had surgery to reconstruct their ACL, approximately one-third (36%) required subsequent surgery to the same knee. One in five (22%) ACL reconstructions failed, requiring additional surgery to the same ACL. Females reported a higher rate of reinjury to an ACL graft than males (27% vs. 13%), but this was not statistically significant.

The medial temporal lobe in dementia with Lewy bodies: a comparative study with Alzheimer's disease

The usefulness of determining medial temporal lobe (MTL) size in differentiating Alzheimer's disease (AD) from other dementia subtypes is unknown. We compared the cross-sectional areas of the MTLs in histological sections from the brains of 18 patients with dementia with Lewy bodies (DLB) but lacking AD changes, 24 DLB patients with concurrent AD pathology, 20 pure AD cases, and 18 age-matched control cases. Duration and severity of disease were comparable between groups. When data for cross-sectional area were expressed as percentages of the average control area, DLB MTLs were significantly larger than either AD or DLB/AD MTLs at rostral levels (86 +/- 16%, 54 +/- 17%, and 66 +/- 23% of control areas, respectively). At caudal levels, DLB MTLs were larger than AD MTLs (80 +/- 20%, 59 +/- 21%, and 77 +/- 26% of control areas in DLB, AD, and DLB/AD, respectively). MTL cross-sectional area often approaches normal in pure DLB, even when disease duration is prolonged and symptoms are end stage. In contrast, a greatly reduced MTL area mitigates against the diagnosis of DLB, unless there are concurrent AD changes.

Mutation measurement in mammalian cells. IV: Comparison of gamma-ray and chemical mutagenesis

The interaction of chemical mutagens with mammalian cells is much more complex than that of gamma-irradiation because of the different ways in which chemical agents react with cell and medium components. Nevertheless, the system previously described for analysis of mutagenesis by gamma-radiation appears applicable to chemical mutagenesis. The approach involves measurement of cell survival, use of caffeine to inhibit repair, analysis of mitotic index changes, and quantitation of microscopically visible structural changes in mitotic chromosomes. The behavior of a variety of chemical mutagens and nonmutagens in this system is described and compared with that of gamma-irradiation. The procedure is simple and the results reasonably quantitative though less so than those of gamma-irradiation. The procedure can be used for environmental monitoring, analysis of mutational events, and individual and epidemiological testing. Mutational events should be classified as primary or secondary depending on whether they represent initial genomic insult, or genomic changes resulting from primary mutation followed by structural changes due to metabolic actions. While caffeine has multiple effects on the mammalian genome, when used under the conditions specified here it appears to act principally as an inhibitor of mutation repair, and so affords a measure of the role of repair in the action of different mutagens on cells in the G2 phase of the life cycle.

Visual problems following dural puncture

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Detection of verotoxigenic Escherichia coli by magnetic capture-hybridization PCR

Magnetic capture-hybridization PCR (MCH-PCR) was used for the detection of 36 verotoxigenic (verotoxin [VT]-producing) Escherichia coli (VTEC), 5 VTEC reference, and 13 non-VTEC control cultures. The detection system employs biotin-labeled probes to capture the DNA segments that contain specific regions of the genes for VT1 and VT2 by DNA-DNA hybridization. The hybrids formed were isolated by streptavidin-coated magnetic beads which were collected by a magnetic particle separator and, subsequently, amplified directly by conventional PCR. The detection system was found to be specific for VTEC: no amplification was obtained from non-VTEC controls, whereas VTEC isolates tested positive for one or two specific PCR products. With 5, 7, or 10 h of enrichment, the limits of detection were 10(3), 10(2), and 10(6) CFU/ml, respectively, by agarose gel electrophoresis. Southern hybridization did not seem to improve the limit of the detection. When applied to food, MCH-PCR was capable of detecting 10(0) CFU of VTEC per g of ground beef with 15 h of nonselective enrichment. The results of MCH-PCR for pure cultures of VT1- and/or VT2-producing E. coli cells were in total agreement with toxin production as measured by a VT enzyme-linked immunosorbent assay.

A baculovirus (Bombyx mori nuclear polyhedrosis virus) repeat element functions as a powerful constitutive enhancer in transfected insect cells

It has been previously reported that baculovirus homologous regions, the regions of baculovirus genomes that contain the origins of DNA replication, can augment the expression of a small number of baculovirus genes in vitro. We are now reporting that a region of the genome of Bombyx mori nuclear polyhedrosis virus (BmNPV) containing the homologous region 3 (HR3) acts as an enhancer for the promoter of a nonviral gene, the cytoplasmic actin gene of the silkmoth B. mori. Incorporation of the HR3 sequences of BmNPV into an actin promoter-based expression cassette results in an augmentation of transgene expression in transfected cells by two orders of magnitude relative to the control recombinant expression cassette. This increase is due to a corresponding increase in the rate of transcription from the actin promoter and not to replication of the expression cassette and occurs only when the HR3 element is linked to the expression cassette in cis. A comparable degree of enhancement in the activity of the silkworm actin promoter occurs also in heterologous lepidopteran cells. Concomitant supplementation of transfected cells with the BmIE1 trans-activator, which was previously shown to be capable of functioning in vitro as a transcriptional co-activator of the cytoplasmic actin gene promoter, results in more than a 1,000-fold increase in the level of expression of recombinant proteins placed under the control of the actin gene promoter. These findings provide the foundation for the development of a nonlytic insect cell expression system for continuous high-level expression of recombinant proteins. Such a system should provide levels of expression of recombinant proteins comparable to those obtained from baculovirus expression systems and should also have the additional advantage of continuous production in a cellular environment that, in contrast to that generated by a baculovirus infection, supports continuously proper posttranslational modifications of recombinant proteins and the capability of expression of proteins from genomic as well as cDNA sequences.

Validity and reliability of measures obtained from the OSI CA-6000 Spine Motion Analyzer for lumbar spinal motion

SUMMARY. The aims of this investigation were firstly to determine the level of agreement between angular measures of lumbar spinal motion recorded by the OSI CA 6000 Spine Motion Analyzer (OSI SMA) and measures obtained from X-rays of subjects without lumbar symptoms, and secondly to determine the intra-rater reliability of measures of lumbar spinal range of motion using the OSI SMA on individuals with lumbar symptoms. To fulfill the first aim 13 asymptomatic subjects (mean age = 28.6 years; SD = 7.1) performed the motions of lumbar flexion, extension, side bending to the right, and side bending to the left twice while wearing the OSI SMA, and once for the exposure of the X-ray. The difference between the measures obtained by the two methods was plotted against the average of those measures for each subject to illustrate the level of agreement of the two methods. Differences between measures that were within one standard deviation of the mean were as follows: for flexion, 7 out of 10 showed less than 8 degrees difference; for extension, 7 out of 10 showed less than 7 degrees difference; for side bending to the right, 11 out of 13 showed less than 6 degrees difference; and for side bending to the left, 10 out of 13 showed less than 5 degrees difference. For asymptomatic subjects, measures obtained from the OSI SMA appear to provide good agreement with measures of lumbar spinal motion in the sagittal and frontal planes as determined by X-rays. To fulfil the second aim of the investigation thirty subjects with lumbar symptoms (mean age = 35.9 years; SD = 14.2) performed four trials of lumbar motion to their maximum for flexion, extension, side bending to the right and left, and rotation to the right and left. The OSI SMA hardware was then completely removed and replaced by the same examiner, and the trials were repeated. ICC values were 0.903 or higher for all motions. These results suggest that active range of motion measures obtained with the OSI SMA in subjects with lumbar symptoms are consistent over repeated trials. Copyright 1997 Harcourt Publishers Ltd.

The differential effects of 12-O-tetradecanoylphorbol-13-acetate on the gap junctions and connexins of the developing mammalian lens

Epithelial cells in primary ovine lens cultures express the gap junction proteins connexin43 (Cx43) and connexin49 (Cx49; a.k.a. MP70), a homologue of mouse connexin50. In contrast, lens cultures of differentiated, fiber-like cells (termed lentoid cells) express Cx49 and connexin46 (Cx46), but not Cx43. To investigate the regulation of lens cell gap junctions by protein kinase C (PKC), differentiating lens cultures were treated with the PKC activator 12-O-tetradecanoylphorbol-13-acetate (beta-TPA). Within 10 min, beta-TPA significantly inhibited the transfer of Lucifer Yellow dye between epithelial, but not lentoid, cells. This inhibition was correlated with the phosphorylation of Cx43 and was followed by the gradual disappearance of Cx43 from cell interfaces. The protein kinase inhibitor staurosporine prevented Cx43 phosphorylation and the loss of Cx43 from intercellular junctions. Following treatment of cultures with beta-TPA for 2-6 hr, Cx49 disappeared from epithelial cell interfaces, and by 24 hr of beta-TPA treatment, levels of Cx49 detected on immunoblots of purified epithelial membrane fractions had also diminished significantly. The beta-TPA-induced loss of Cx49 both from regions of epithelial cell contact and from isolated membranes was correlated with the disappearance of Cx49 mRNA. In contrast to the epithelial connexins, the lentoid connexins Cx49 and Cx46 were unaffected by even extended beta-TPA treatment. In spite of lentoid dye transfer being refractory to beta-TPA, significant levels of PKC-alpha (a beta-TPA-sensitive isoform) were detected in the lentoid cell. The response of lens gap junctions to beta-TPA depends upon the stage of differentiation and the complement of connexins expressed. The contrasting effects of beta-TPA on Cx43 and Cx49 in lens epithelial cells indicate a fundamental difference in the regulation of these connexin proteins in the developing mammalian lens.

Modality-specific processing streams in verbal working memory: evidence from spatio-temporal patterns of brain activity

The present study was concerned with whether there are separate, modality-specific processing "streams" in verbal working memory for information that is heard or read. We used event-related brain potentials (ERPs) recorded from scalp of normal humans to show between-modality differences in spatio-temporal patterns of brain activity during retention in working memory of aurally or visually presented verbal information. The ERP patterns suggested that a sustained, automatically maintained auditory store was activated by auditory presentation and a transient, visual-verbal store was activated by visual presentation. In addition to these modality-specific differences, the ERPs indicated that the phonological loop was activated in both modalities and further suggested that the onset of phonological loop activation was earlier for auditory presentation.

Urinary oxalate excretion and its role in vulvar pain syndrome

OBJECTIVE

This study was undertaken to determine the urinary oxalate excretion patterns in patients with vulvodynia compared with controls and to evaluate antioxalate therapy in women with vulvar pain syndrome (vulvodynia).

STUDY DESIGN

A total of 130 consecutive patients with vulvar pain syndrome and 23 volunteers without symptoms collected urine specimens for 24 hours; each voiding was saved in individual labeled containers and refrigerated. The specimens were analyzed individually for oxalate and calculated according to 24-hour concentration, volume, and peak oxalate by hour. A total of 59 patients were treated with low-oxalate diets and calcium citrate for 3 months and evaluated for objective relief of vulvar pain.

RESULTS

The 24-hour excretion of oxalate was almost identical in controls and vulvodynia patients. The total 24-hour excretion was directly proportional to the volume of urine excreted (p < 0.001). No significant differences were found in peak oxalate excretion (95% confidence intervals). The number of voidings was higher in the vulvodynia cohort (p < 0.02). The 59 women with elevated oxalate concentrations (> 1 mg/40 dl) were treated with an antioxalate regimen. Fourteen (24%) demonstrated an objective response, but only 6 (10%) could have pain-free sexual intercourse.

CONCLUSIONS

Urinary oxalates may be nonspecific irritants that aggravate vulvodynia; however, the role of oxalates as instigators is doubtful.

Restoration of thymocyte development and function in zap-70-/- mice by the Syk protein tyrosine kinase

The Syk family of protein tyrosine kinases, consisting of ZAP-70 and Syk, associate with the pre- and alphabeta T cell antigen receptors (TCRs) and undergo tyrosine phosphorylation and activation following receptor engagement. Thymocyte development in zap-70-/- mice is blocked at the CD4+CD8+ TCR(lo) stage. The presence of Syk in the thymus has raised the possibility that Syk may be able to mediate TCR function. To determine if Syk can play a role in thymocyte development, we generated zap-70-/- mice expressing a human syk cDNA. Syk expression restored both thymocyte development and function. In addition, Syk function required the CD45 transmembrane protein tyrosine phosphatase. Hence, ZAP-70 and Syk can play overlapping functions and exhibit similar regulatory mechanisms in mediating alphabeta T cell development.