Estrogen supplementation in the posthypoxic myoclonus rat model

The objective of the study was to investigate the effects of estrogen on severity and duration of myoclonus in the rat cardiac arrest model of posthypoxic myoclonus. Female sex hormones affect a variety of movement disorders and alter dopaminergic and serotonergic pharmacology. Although women represented three-fourths of patients from the original report of Lance and Adams and 80% of the largest published series, the impact of estrogens on myoclonus has never been studied. Twelve previously ovariectomized female rats underwent 8 minutes of mechanically induced cardiac arrest and were resuscitated according to a standardized protocol. On the same day, they were randomly assigned to subcutaneous treatment with a 21-day, 0.5-mg, 17 beta-estradiol or matching placebo pellet. Animals were tested daily with 7 sets of 45 auditory stimuli for 10 days, and myoclonus scores were obtained using a 5-point interval scale. Comparisons were based on two-sample Wilcoxon rank-sum tests. Estrogen treatment significantly enhanced myoclonus intensity and duration: mean peak myoclonus score, 210.2 +/- 18.0 versus 180 +/- 28.5 (p = 0.031); mean number of days above baseline, 9.2 +/- 0.4 versus 5.7 +/- 2.3 (p = 0.004); mean score on day 10, 90.7 +/- 38.7 versus 27.0 +/- 20.6 (p = 0.016). All estrogen-treated animals were above baseline on day 10 compared with none in the placebo group. Estrogen enhances and prolongs posthypoxic myoclonus, suggesting that female gender and estrogen status may play a pivotal role as a risk factor for human posthypoxic myoclonus.

Menstrual-related changes in motoric function in women with Parkinson's disease

Questionnaire studies have found that parkinsonism worsens in women during the premenstrual period, when estrogen and progesterone levels are presumably at their nadir. To assess this patient-based observation and correlate motor signs with hormonal levels, the authors prospectively studied 10 menstruating women with PD in their "off" state, on 5 successive weeks. Although PD severity fluctuated during the study period, there was no significant correlation between the objective or subjective measures of parkinsonism and estrogen and progesterone levels.

Cognitive and motor function in patients with Parkinson's disease with and without depression

The objective of this study was to define risk factors for depression in patients with idiopathic Parkinson's disease (PD) and to evaluate the correlation of depression with cognitive function and the primary domains of parkinsonian motor dysfunction tremor, bradykinesia, rigidity, gait and balance impairment. The risk factors for depression in patients with PD remain controversial. Several investigators have demonstrated a significant association between cognitive dysfunction and depression, but motoric and disease variables can confound this evaluation and have shown an inconsistent relation to depression. A consecutive series of 88 patients with PD were examined using the motor subscale of the Unified Parkinson's Disease Rating Scale (UPDRSm), Hoehn-Yahr stage (HY), and Hamilton Rating Scale for Depression (HRSD). Major depression was diagnosed according to the criteria in the Diagnostic and Statistic Manual of Mental Disorders, 4th edition. Gender, age, handedness, PD duration, side of PD onset, motor fluctuations, UPDRSm total score, daily Levodopa dose, and Mini-Mental State Examination score (MMSE) were analyzed using multivariate and univariate logistic regression, Fisher's Exact test, and Pearson correlations. Major depression was diagnosed in 12 patients (7.3%). Low MMSE score, axial bradykinesia, gait and balance impairment were strongly significant predictors of depression. In conclusion, depression and physical function are important factors impairing the quality of life for patients with PD, and regular depression screening and treatment should focus on patients with PD who have cognitive impairment, high axial bradykinesia, gait and balance impairment.

A zinc finger domain gene in the lizard, Calotes versicolor, shows extensive homology with the mammalian ZFX and is expressed embryonically

A 590-bp long zinc finger domain DNA fragment has been isolated by polymerase chain reaction from the lizard, Calotes versicolor, employing the primers used for amplifying the zinc finger domain of the human Y-chromosomal gene, ZFY. Cloned in pUC18, the fragment, called CvZfa, was sequenced and its expression during development was studied. At the nucleotide and amino acid level CvZfa shows respectively 83% and 90% identity with the human ZFY, but its extent of homology is greater with the ZFX of human (86% at nucleotide and 92% at amino acid level) and the ZFY-like genes of turtle and chick. Similarly its homology with the mouse Zfx and Zfa is much greater than that with Zfy-1 and Zfy-2. It appears that the mammalian ZFX (Zfx) evolved from reptilian ancestors with a considerable degree of conservation, but the ZFX to ZFY divergence within the class mammalia was more rapid. The CvZfa transcripts were seen in all the embryonic stages from which RNA was analysed. The whole mount in situ hybridization with the posteriorly placed mesonephros and the gonadal primordia of 10 to 25 day old embryos showed signal selectively in mesonephros of the 20 and 25 day embryos. There was no signal in the genital ridge. Thus CvZfa may not have a direct role in gonadogenesis of C. versicolor, but the possibility of its inductive role in the formation of adreno-gonadal axis through mesonephros cannot be discounted.

Acute orthostatic hypotension when starting dopamine agonists in Parkinson's disease

OBJECTIVE

To study the frequency and severity of acute orthostatic hypotension (OH) in patients with Parkinson's disease who are starting dopamine agonist therapy.

PATIENTS AND METHODS

In the context of an outpatient clinical practice, 29 consecutive patients with Parkinson's disease who were starting dopamine agonist therapy were brought into the clinic for their first dose of agonist. After a baseline supine and standing blood pressure assessment, patients were given a test dose of either pergolide mesylate (0.025, 0.05, 0. 125, or 0.25 mg), pramipexole dihydrochloride (0.125 mg), or ropinirole hydrochloride (0.125 or 0.25 mg). At 3 selected times, blood pressure readings were repeated in the supine and standing positions.

MAIN OUTCOME MEASURE

Orthostatic hypotension was defined as a drop in either systolic blood pressure of more than 25 mm Hg or diastolic pressure of more than 10 mm Hg. Patients with OH before the administration of the dopamine agonist were excluded.

RESULTS

Ten subjects (34%) met the criteria for acute OH. There was no evidence that OH was related to the use of a specific dopamine agonist or the concurrent use of levodopa. Of the patients who met the criteria for OH, only 3 (30%) had symptoms of OH, such as lightheadedness or general malaise.

CONCLUSIONS

Acute OH occurs frequently when starting dopamine agonist therapy in Parkinson's disease, but is frequently not appreciated by patients. Knowledge of acute blood pressure responses may be useful when making decisions regarding agonist titration schedules in clinical practice. Arch Neurol. 2000;57:1461-1463

Sequencing of 3-O sulfate containing heparin decasaccharides with a partial antithrombin III binding site

Heparin- and heparan sulfate-like glycosaminoglycans (HLGAGs) represent an important class of molecules that interact with and modulate the activity of growth factors, enzymes, and morphogens. Of the many biological functions for this class of molecules, one of its most important functions is its interaction with antithrombin III (AT-III). AT-III binding to a specific heparin pentasaccharide sequence, containing an unusual 3-O sulfate on a N-sulfated, 6-O sulfated glucosamine, increases 1,000-fold AT-III's ability to inhibit specific proteases in the coagulation cascade. In this manner, HLGAGs play an important biological and pharmacological role in the modulation of blood clotting. Recently, a sequencing methodology was developed to further structure-function relationships of this important class of molecules. This methodology combines a property-encoded nomenclature scheme to handle the large information content (properties) of HLGAGs, with matrix-assisted laser desorption ionization MS and enzymatic and chemical degradation as experimental constraints to rapidly sequence picomole quantities of HLGAG oligosaccharides. Using the above property-encoded nomenclature-matrix-assisted laser desorption ionization approach, we found that the sequence of the decasaccharide used in this study is DeltaU(2S)H(NS,6S)I(2S)H(NS, 6S)I(2S)H(NS,6S)IH(NAc,6S)GH(NS,3S,6S) (+/-DDD4-7). We confirmed our results by using integral glycan sequencing and one-dimensional proton NMR. Furthermore, we show that this approach is flexible and is able to derive sequence information on an oligosaccharide mixture. Thus, this methodology will make possible both the analysis of other unusual sequences in HLGAGs with important biological activity as well as provide the basis for the structural analysis of these pharamacologically important group of heparin/heparan sulfates.

Spectroscopic imaging of radiation-induced effects in the white matter of glioma patients

External radiation therapy of brain tumors may cause adverse effects on normal brain tissue, resulting in severe neuropsychological and cognitive impairment. We investigated the late delayed radiation effects in the white matter (WM) using (1)H magnetic resonance spectroscopic imaging ((1)HMRSI). Nine glioma patients with local radiation-induced signal abnormalities in the T(2)-weighted MR images were studied with nine age- and sex-matched controls. The metabolite ratios in the radiation-induced hyper intensity area (RIHA) and in the normal appearing white matter (NAWM) of the patients were compared with respective WM areas of the controls. In RIHA, choline/creatine (Cho/Cr) was 17% decreased (1.22 +/- 0.13 vs 1.47 +/- 0.16, p = 0.0027, significant (s), unpaired Student's t test with Bonferroni correction) in the patients compared to the controls, while there was no difference in N-acetyl aspartate/Cr (NAA/Cr) (2.49 +/- 0.57 vs 2.98 +/- 0.32, p = 0.039) or NAA/Cho (2. 03 +/- 0.40 vs 2.04 +/- 0.17, p = 0.95). In NAWM, Cho/Cr was 24% decreased (1.21 +/- 0.15 vs 1.59 +/- 0.13, p < 0.0001, s) and NAA/Cho was 20% increased (2.49 +/- 0.49 vs 1.98 +/- 0.15, p = 0. 0082, s) in the patients compared to the controls, while there was no difference in NAA/Cr (2.99 +/- 0.46 vs 3.16 +/- 0.32, p = 0.38). NAA(RIHA)/NAA(NAWM) was 25% decreased (0.75 +/- 0.20 vs 1.00 +/- 0. 12, p = 0.0043, s) and Cr(RIHA)/Cr(NAWM) was 16% decreased (0.89 +/- 0.15 vs 1.06 +/- 0.10, p = 0.013, s) in the patients compared to the controls, while there was no difference in Cho(RIHA)/Cho(NAWM) (0.92 +/- 0.23 vs 0.98 +/- 0.10, p = 0.47). (1)HMRSI reveals widespread chemical changes in the WM after radiation therapy. In RIHA, there is loss of NAA, Cho, and Cr implying axonal and membrane damage and in NAWM, there is loss of Cho, reflecting membrane damage.

Cloning of the Arabidopsis clock gene TOC1, an autoregulatory response regulator homolog

The toc1 mutation causes shortened circadian rhythms in light-grown Arabidopsis plants. Here, we report the same toc1 effect in the absence of light input to the clock. We also show that TOC1 controls photoperiodic flowering response through clock function. The TOC1 gene was isolated and found to encode a nuclear protein containing an atypical response regulator receiver domain and two motifs that suggest a role in transcriptional regulation: a basic motif conserved within the CONSTANS family of transcription factors and an acidic domain. TOC1 is itself circadianly regulated and participates in a feedback loop to control its own expression.

Evolutionary conservation of the gene Cvsox9 in the lizard, Calotes versicolor, and its expression during gonadal differentiation

We have cloned and sequenced an orthologue of the human SOX9 gene in the lizard, Calotes versicolor, which lacks heteromorphic sex chromosomes as well as temperature-dependent sex determination. PCR amplification of Calotes cDNA using human SOX9 primers yielded an 861-bp fragment which harboured the high-mobility group domain and flanking sequences and had identity greater than 85% at nucleotide and greater than 90% at amino acid level with the hitherto known homologues of Sox9, demonstrating its evolutionary conservation. CvSox9 makes an approx. 5-kb transcript which is expressed in the genital ridge and mullerian duct of all the embryos from their very inception. In the genital ridge the expression in day 40 and day 45 embryos is confined to the embryonic testis (medulla) of only 50% embryos, indicating a shift in the expression from non-gonad-specific to testis-specific. The temporal and cell-specific expression in the genital ridge suggests a vital role for CvSox9 in the determination and/or differentiation of testis.

Post stapedotomy hyperacousis-A mechanical explanation

Mechanical explanation for the hyperacousis that sometimes occurs after stapedectomy or stapedotomy is presented.

Removal of a Fish Bone in the Thyroid Gland without the Need for Thyroid Lobectomy

We report the first published case of the removal of a migratory fish bone from the thyroid gland that did not necessitate a thyroid lobectomy.

Removal of a fish bone in the thyroid gland without the need for thyroid lobectomy

We report the first published case of the removal of a migratory fish bone from the thyroid gland that did not necessitate a thyroid lobectomy.

Objective changes in motor function during placebo treatment in PD

OBJECTIVE

To examine the frequency, temporal development, and stability of objectively derived motor changes during placebo treatment in PD and to define the clinical domains and demographic groups most affected.

BACKGROUND

Placebo effects are documented in neurology, but the timing and specific disabilities most susceptible to changes during placebo treatment in PD have not been examined.

METHODS

The authors examined the placebo-treated group from a randomized, multicenter, placebo-controlled clinical trial of monotherapy ropinerole in PD patients without motor fluctuations. In 105 patients, they evaluated placebo-associated effects on the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS), dividing the motor examination into four categories: tremor, bradykinesia, rigidity, and gait/balance/midline functions. The motor UPDRS and its subscales were compared over time (at baseline and at 4, 12, and 24 weeks) using Wilcoxon's signed rank test. They applied a rigorous definition of placebo-associated improvement as an improvement over baseline score in motor UPDRS of at least 50% or a change in at least two motor items at any one visit by > or =2 points.

RESULTS

During the 6-month study, 16% of subjects improved on placebo treatment. The prevalence of response was steady (8 to 9%) at any one visit without a predominance of an early effect. No patient showed a placebo-associated improvement on all visits. All domains of parkinsonian disability were subject to placebo-associated improvement, with a trend toward more response in bradykinesia and rigidity than in tremor or gait/balance/midline function. Gender, age, disease duration, and baseline disability score did not influence the likelihood of improvement in association with placebo treatment.

CONCLUSION

Based on a rigorous definition of placebo-associated improvement, prominent improvements in objective measures of PD disability occur during clinical trials. Because placebo-associated improvements occur throughout a 6-month trial, placebo-controlled studies in PD should be at least 6 months to capture early as well as late improvements.

Effects of central dopaminergic stimulation by apomorphine on speech in Parkinson's disease

OBJECTIVE

To determine the effect of central dopaminergic stimulation with apomorphine on speech in PD.

BACKGROUND

Most patients with PD have a speech disorder. Of those, 89% have involvement of laryngeal function, and 45% have additional articulatory dysfunction. The effect of dopaminergic medications on these two dimensions of speech impairment in PD has not been selectively studied.

METHODS

In a randomized, double-blind, placebo-controlled crossover design, patients with PD and speech impairment, Hoehn and Yahr stages 2 to 4 "off," and without severe dyskinesias were given placebo or apomorphine injections 0.05 mg/kg subcutaneously during two consecutive outpatient visits. They were pretreated with domperidone for 48 hours and were tested off their parkinsonian medications for 12 hours. Laryngeal function was assessed by maximum sustained vowel phonations and comfortable vowel phonations. Articulatory function was evaluated by speech intelligibility score, speaking rate, and efficiency ratio.

RESULTS

Ten patients, mean age 73.4 years (SD = 6.6), disease duration 8.7 years (SD = 6.3), were tested. The baseline motor score on the Unified Parkinson's Disease Rating Scale (UPDRSm) and all experimental speech variables were equivalent on both placebo and apomorphine days. At a dose of apomorphine that provoked improvement in UPDRSm (p = 0.0078), no index of either laryngeal or articulatory function improved significantly after apomorphine administration.

CONCLUSION

Laryngeal and articulatory speech components are not under prominent dopaminergic control in PD. Treatment regimens should focus on nondopaminergic pharmacology and other therapies.

Decreased color discrimination and contrast sensitivity in Parkinson's disease

Patients with Parkinson's disease (PD) often complain of blurred vision or even of distinctive visual disturbances like hallucinations and illusions. Recent studies have emphasized the potential influence of primary visual deficits of color and contrast discrimination. To study primary visual function, we studied color discrimination (CD) and contrast sensitivity (CS) during 'on' medication in PD patients and compared them to non-PD subjects. Twenty one PD patients were compared to 30 age-matched controls using CD tested by the D-15 Lanthony test (D15) and the Farnsworth-Munsell 100 Hue test (FM) and CS tested by the Pelli-Robson (PL) and the Vis-Tech tables (VT). We excluded subjects with a visual acuity </=0.6 Snellen fraction or known ophthalmological diseases. PD patients showed greater impairment on all visual tests than controls. This difference was significant for the FM test (P<0.001), the spatial frequencies 12 and 18 cpd (cycles per degree) of the VT test (P<0.05) and both the monocular and binocular PR tests (P<0.05). Most tests for CS and CD showed statistical independency. CS deficits, but not CD deficits, correlated with age in both patients and controls. This study documents major and independent impairment of both color and contrast discrimination in PD patients. Further studies should elucidate possible clinical implications and correlations, such as the frequency of falls or visual hallucinations.

Sequencing complex polysaccharides

Although rapid sequencing of polynucleotides and polypeptides has become commonplace, it has not been possible to rapidly sequence femto- to picomole amounts of tissue-derived complex polysaccharides. Heparin-like glycosaminoglycans (HLGAGs) were readily sequenced by a combination of matrix-assisted laser desorption ionization mass spectrometry and a notation system for representation of polysaccharide sequences. This will enable identification of sequences that are critical to HLGAG biological activities in anticoagulation, cell growth, and differentiation.

Opinion of New Zealand physicians on management of acute ischaemic stroke: results of a national survey

BACKGROUND

Randomised trials have evaluated various treatments for acute ischaemic stroke, but it is unclear how the results of these studies are used in everyday practice.

AIMS

To obtain the opinions of physicians on the management of acute ischaemic stroke.

METHODS

A questionnaire was sent to 368 New Zealand Fellows of the Royal Australasian College of Physicians. The survey included questions about the availability of hospital services for stroke patients, management of acute ischaemic stroke and opinion on the efficacy of treatments used in acute ischaemic stroke.

RESULTS

Of the 293 physicians who responded to the questionnaire, 171 managed patients in the first week after stroke. Forty-seven per cent of these physicians were general physicians. Ninety-five per cent usually managed these patients in a general medical ward. Only five physicians admitted patients to an acute stroke unit and only 57% considered acute stroke units were beneficial. Aspirin was usually or sometimes used for patients with acute ischaemic stroke by 92% of physicians, intravenous heparin by 43%, low-dose subcutaneous heparin by 41%, low-molecular-weight heparin by 25% and tissue-plasminogen activator (t-PA) by 3%. Two thirds considered that aspirin was definitely beneficial, but most were uncertain about the efficacy of intravenous heparin, low-dose subcutaneous heparin, low-molecular-weight heparin and t-PA. Sixty-two per cent were prepared to begin aspirin and 21% subcutaneous heparin before computerised tomography (CT). Twenty-three per cent used anti-hypertensive treatment in the first few hours after an ischaemic stroke.

CONCLUSIONS

Several common deficiencies in the management of acute ischaemic stroke were identified. The widespread lack of stroke units, use of aspirin and heparin before CT, and lowering of blood pressure after an acute ischaemic stroke differed from accepted guidelines. Many physicians used heparin despite lack of evidence from randomised trials that it is beneficial. The development of stroke units and the appointment of physicians with a special interest in the management of stroke may improve the management of patients with acute stroke.

Temporal difference between testis and ovary determinations with possible involvement of testosterone and aromatase in gonadal differentiation in TSD lacking lizard, Calotes versicolor

In the garden lizard, Calotes versicolor, which lacks identifiable sex chromosomes, incubation temperature also does not have a deterministic effect on the gender. However, the embryos reared at high temperature (33-35 degrees C) have a shorter duration of incubation as well as gonadal differentiation. In contrast, exogenous application of the male hormone testosterone to embryos at ambient temperature (28 degrees C) results in almost all individuals with only testis. Thus the testosterone treatment reverts genic females to males and accelerates the differentiation of testis, a feature similar to the high-temperature treatment. Treatment of eggs with estradiol shows no difference from that seen in the untreated eggs. The present series of experiments was done to establish the "window" of testosterone sensitivity and to understand the interaction between sex hormones and high temperature on gonadal differentiation. The period between day 5 and 15 of embryonic development was the window period of testosterone sensitivity for sex reversal. This period coincided with the formation of the genital ridge and its differentiation into cortex and medulla. Treatment of the 33 degrees C-reared embryos with testosterone resulted in hatchlings of both the sexes, in contrast to only males at the ambient temperature. In contrast, at the same temperature (33 degrees C), all the dihydrotestosterone (nonaromatisable testosterone)-treated embryos hatched into males. However, those given estradiol showed no sex bias regardless of the day of application and the concentration of drug. Eggs were also treated with aromatase inhibitor, CGS 16949 A, at ambient temperature and at 33 degrees C. All the 33 degrees C eggs to which the drug was given on day 25 hatched into males. These results suggest that though high temperature has no direct effect on sex determination in this species, it may have a stimulatory effect on aromatase activity, leading to the conversion of the exogenously applied testosterone into estradiol and permitting ovarian differentiation in the genic females. It also follows from the present report that the pathway of testis formation in Calotes versicolor is triggered much earlier, and irreversibly, than that for the ovary.

Characterisation of developmentally regulated chromatin structure in the coding region of the proto-oncogene, c-fos, in the male laboratory mouse

In mouse, tissue-specific developmental de novo methylation of the proto-oncogene c-fos, which is abundantly expressed during embryonic stages, occurs perinatally (between the day of birth to 20 dpp) and is maintained in the adult. In liver, where c-fos is only active up to the day of birth, the gene has more sites methylated than in brain, where it is expressed until about day 5 post-partum. We have studied chromatin organisation of c-fos and compared thisto DNA methylation in the fetal and adult brain and liver. Purified nuclei of these tissues from fetus as well as adult were digested with the restriction enzyme Mspl. DNA was extracted from the Mspl digested chromatin and probed with two DNA segments covering the major part of the body of the gene (from distal part of second exon to major part of fourth exon). Southern hybridisation studies revealed that in the fetus, in both liver and brain, the chromatin in the coding region was sensitive to Mspl digestion and the extent of sensitivity was nearly the same between the two. In the adult tissues, however, chromatin from brain was almost as sensitive as in the fetus, but in the liver it was highly resistant to Mspl. We suggest that a shift from the undermethylated state in the fetus to the heavy methylated state in the adult causes a corresponding change in the organisation of chromatin of c-fos in the coding region. Furthermore, the difference in the tissue-specificity in the methylation induced chromatin compaction could be due to differences in the transcription levels of c-fos and de novo methylation during early neonatal development.

Advantages of a modified scoring method for the Rush Video-Based Tic Rating Scale

Previously, we published a video-based objective rating scale of tics that met reliability and validity criteria for measurement of five domains of tic disability. In the original form, the scale's metric properties did not permit internal comparison of each of the five domains of impairment and did not provide a total score for use as a primary outcome measure. In this study, we retained the original scale and videotape protocol but tested whether a modified scoring system corrected these limitations. The new scoring method rated assigned tic data to ratings of 0-4 on five disability categories: number of body areas, frequency of motor tics, frequency of phonic tics, severity of motor tics, and severity of phonic tics. The sums of these ratings yielded a total score of overall tic disability (0-20). In a series of 31 patients with Gilles de la Tourette syndrome, we assessed Spearman correlation coefficients for the old and new scoring systems as well as the correlation of the new ratings with the objectively derived sections of the Yale Global Tic Severity Scale (YGTSS), another valid and reliable scale used in clinical practice and research. For each domain, the rank order for the scores on the original scale was well retained in the new scores. Likewise, for each domain, ranking with the new scoring system correlated well with scores on the comparable objective item from the YGTSS. The new total score accurately captured the rank order of the combined five domains from the original scale and correlated well with the total objective motor plus phonic tic score from the YGTSS and the YGTSS Tourette Syndrome Overall Impairment Rating. These data demonstrate that the modified videotape-based scoring system retains the essential information gathered in the original Rush scale. The modification provides comparisons among the five assessed domains and a total objectively based disability score that can be used as a single outcome measure for assessing tic disability.

Approach to Surgery in the Middle Ear without the Need for an Aural Speculum

This article describes a new approach to permeatal surgery in the middle ear that does not require the use of an aural speculum.

Approach to surgery in the middle ear without the need for an aural speculum

This article describes a new approach to permeatal surgery in the middle ear that does not require the use of an aural speculum.

Post stapedotomy hyperacousis - a mechanical explanation

A mechanical explanation for the hyperacousis that sometimes occurs after stapedectomy or stapedotomy is offered.

Molecular characteristics of fibroblast growth factor-fibroblast growth factor receptor-heparin-like glycosaminoglycan complex

Fibroblast growth factor (FGF) family plays key roles in development, wound healing, and angiogenesis. Understanding of the molecular nature of interactions of FGFs with their receptors (FGFRs) has been seriously limited by the absence of structural information on FGFR or FGF-FGFR complex. In this study, based on an exhaustive analysis of the primary sequences of the FGF family, we determined that the residues that constitute the primary receptor-binding site of FGF-2 are conserved throughout the FGF family, whereas those of the secondary receptor binding site of FGF-2 are not. We propose that the FGF-FGFR interaction mediated by the 'conserved' primary site interactions is likely to be similar if not identical for the entire FGF family, whereas the 'variable' secondary sites, on both FGF as well as FGFR mediates specificity of a given FGF to a given FGFR isoform. Furthermore, as the pro-inflammatory cytokine interleukin 1 (IL-1) and FGF-2 share the same structural scaffold, we find that the spatial orientation of the primary receptor-binding site of FGF-2 coincides structurally with the IL-1beta receptor-binding site when the two molecules are superimposed. The structural similarities between the IL-1 and the FGF system provided a framework to elucidate molecular principles of FGF-FGFR interactions. In the FGF-FGFR model proposed here, the two domains of a single FGFR wrap around a single FGF-2 molecule such that one domain of FGFR binds to the primary receptor-binding site of the FGF molecule, while the second domain of the same FGFR binds to the secondary receptor-binding site of the same FGF molecule. Finally, the proposed model is able to accommodate not only heparin-like glycosaminoglycan (HLGAG) interactions with FGF and FGFR but also FGF dimerization or oligomerization mediated by HLGAG.

Rare middle ear anomaly in a patient with Turner's syndrome

A patient with Turner's syndrome presented with a rare anomaly of absent oval window, inferiorly placed facial nerve, and abnormal stapes. To our knowledge, this is the first report of this combination of malformations.

Animal model of posthypoxic myoclonus: effects of serotonergic antagonists

OBJECTIVE

To study specific serotonin (5-hydroxytryptamine [5-HT]) receptor subtype antagonists in an animal model of posthypoxic myoclonus.

BACKGROUND

Although serotonergic system dysfunction is implicated in posthypoxic myoclonus, anatomic specificity and linkage to receptor subtypes are not delineated.

METHODS

The authors performed a pharmacologic study to identify specific serotonin receptor subtype antagonists effective in inhibiting myoclonus in posthypoxic rats. Sprague-Dawley rats underwent cardiac arrest for 8 minutes and were resuscitated. On the day of pharmacologic testing, animals were rated every 10 minutes at -30 minutes to time 0 (drug injection) and from +60 to +150 minutes. Using a blinded methodology, animals were injected with normal saline, vehicle, or one of seven serotonin antagonists given at a dose that maintains serotonin receptor subtype specificity: WAY100135 (5-HT1A), methiothepin mesylate (5-HT1B/1D/2), mesulergine hydrochloride (5-HT2A/2B), GR 127935 (5-HT1D), SR 46349 (5-HT2), ondansetron (5-HT3), or GR 125487 (5-HT4). Drugs that produced a significant decrease in myoclonus compared with the control were studied in a dose-response study with six doses across a range from the original dose studied to 10% of that dose.

RESULTS

Two drugs were significantly different from placebo: methiothepin mesylate and mesulergine hydrochloride. GR 127935 showed a trend toward reducing myoclonus. Dose-response studies showed that all doses of methiothepin mesylate and the three highest doses of mesulergine hydrochloride inhibited myoclonus effectively.

CONCLUSIONS

5-HT1B, 5-HT2A/2B, and possibly 5-HT1D receptor subtypes likely play a role in posthypoxic myoclonus. More specific 5-HT antagonists that affect these receptor subtypes are candidates for future testing in this model and in Lance-Adams syndrome.

Tissue-specific characterisation of DNA methylation in the gonad-specific proto-oncogene, c-mos, in the male laboratory mouse

The proto-oncogene, c-mos, which is expressed only in the germ cells of both testis and ovary, plays an important role in meiotic maturation of these cells. In this research, the methylation status of several CpG sites, present both upstream and within the coding region of the c-mos gene, has been studied. The HpaII and HhaI sites examined in the 5' half of the coding region were unmethylated in both the c-mos expressing and non-expressing tissues. A HhaI site, h3, present 380bp downstream of the transcription start site, was unmethylated in germ cells, but was partially methylated in the somatic tissues, inversely correlating with the expression status of the gene. In contrast to these tissues, in the mouse fibroblast cell line L929, all the analysed sites were completely methylated.

Hallucinations, sleep fragmentation, and altered dream phenomena in Parkinson's disease

In a series of consecutively randomized outpatients who had Parkinson's disease (PD), we examined the association of three behaviors: sleep fragmentation, altered dream phenomena, and hallucinations/illusions. Using a log-linear model methodology, we tested the independence of each behavior. Sixty-two percent of the subjects had sleep fragmentation, 48% had altered dream phenomena, and 26% had hallucinations/illusions. Eighty-two percent of the patients with hallucinations/illusions experienced some form of sleep disorder. The three phenomena were not independent. The interaction between sleep fragmentation and altered dream phenomena was strongly statistically significant. Likewise, a significant interaction existed between altered dream phenomena and hallucinations/illusions. No interaction occurred between sleep fragmentation and hallucinations/illusions. Sleep fragmentation, altered dream phenomena, and hallucinations/illusions in PD should be considered distinct but often overlapping behaviors. The close association between altered dream phenomena and hallucinations suggests that therapeutic interventions aimed at diminishing dream-related activities may have a specific positive impact on hallucinatory behavior.

Poor visual discrimination and visual hallucinations in Parkinson's disease

This study examined the relationship between deficits in color and contrast discrimination and visual hallucinations (VH) in patients with Parkinson's disease (PD) and normal visual acuity. Thirty-five nondemented and nonpsychotic PD patients with normal visual acuity and without major ophthalmologic disease were interviewed twice and divided into two groups: hallucinators (n = 14) and non-hallucinating controls (n = 21). The groups were compared for color vision (assessed by Lanthony D-15 [LD] and Farnsworth-Munsell 100 hue [FM] tests), and for contrast sensitivity (tested by Vis tech tables [VT] and monocular and binocular Pelli-Robson test [PR]). There was no difference in age, duration or stage of PD, or dosage or duration of levodopa therapy between the two groups. Parkinson's disease patients showed impairment on all visual tests, with the hallucinators performing worse than the controls on all tests. This difference was significant for the LD (p < 0.007), the VT at 1.5 and 3 cycles per degree (p < 0.037 and 0.043, respectively) and the monocular PR tests (p < 0.049). The results led the authors to conclude that in patients with normal visual acuity, those with VH show added visual deficits of color and contrast discrimination. These ophthalmopathies may therefore be facilitating factors for visual hallucinations in PD and justify more focused research on the pathophysiology of visual hallucinations in Parkinson's disease.

Cerebral processes related to visuomotor imagery and generation of simple finger movements studied with positron emission tomography

Positron emission tomography was used to compare the functional anatomy of visual imagination and generation of movement. Subjects were asked to generate visual images of their finger movement in response to a preparatory signal. Four conditions were tested: in two, no actual movement was required; in the other two, a second signal prompted the subjects to execute the imagined movement. Which movement to imagine was either specified by the preparatory stimulus or freely selected by the subjects. Compared with a rest condition, tasks involving only imagination activated several cortical regions (inferoparietal cortex, presupplementary motor area, anterior cingulate cortex, premotor cortex, dorsolateral prefrontal cortex) contralateral to the imagined movement. Tasks involving both imagination and movement additionally increased activity in the ipsilateral cerebellum, thalamus, contralateral anteroparietal, and motor cortex and decreased activity in the inferior frontal cortex. These results support the hypothesis that distinct functional systems are involved in visuomotor imagination and generation of simple finger movements: associative parietofrontal areas are primarily related to visuomotor imagination, with inferior frontal cortex likely engaged in active motor suppression, and primary motor structures contribute mainly to movement execution.

Vital signs services for secure telemedicine applications

Telemedicine using teleconference provides only a part of the picture. The remote patient's electronic medical record and vital signs may often be essential for proper diagnosis and treatment. While there are commercial solutions for telemonitoring, they do not address issues such as security and interoperability leveraging the growing public communications infrastructure. On the other hand there are performance considerations due to the quality of service over available communications media that can hinder real-time operation. The objective of this research effort is to develop secure tele-monitoring facilities that enable healthcare providers to collaborate over public communication networks; to securely convey their patient's vital signs to a remote specialist; and to enable "near real-time" examination of those vital sign data. It is our belief that such applications can help overcome barriers to quality healthcare in the scattered populations of rural areas enabling telemedicine to be a part of the practice of medicine. The authors, who are developing secure telemedicine applications, describe their approach in developing secure vital signs services.

De novo methylation of the proto-oncogene, c-fos, during development occurs step-wise and directionally in the laboratory mouse

We have analyzed the ontogenic initiation and maintenance of methylation of certain Hpall (m), Hhal (H), Hincll (Hc), and Sall (SI)-specific CpG sites in the coding region of the proto-oncogene, c-fos, through testicular cells, sperm, and fetal, neonatal, and adult somatic tissues. The results show that 1) sperm-derived methylated sites get demethylated in early development. However, unlike other studied genes, they remain so at least up to day 13.5 post coitum (pc); 2) de novo methylation proceeds unidirectionally in a step-wise, site-specific manner between m5-m3 sites; 3) the mature, tissue-specific, adult methylation pattern is established between day 0 and day 20 of neonatal development; 4) the Hc and SI sites (CGTCGAC), occurring at an interval of one nucleotide, are only partially methylated in all the tissues; and 5) m3 and H1 sites, which occur close to an Sp1 motif, escape methylation in most of the tissues. The present study on the embryonic gene, c-fos, thus provides a novel pattern of de novo methylation in development. Also, it suggests that close proximity of CpGs may prevent methylation.

Increased choline signal coinciding with malignant degeneration of cerebral gliomas: a serial proton magnetic resonance spectroscopy imaging study

The authors tested the hypothesis that proton magnetic resonance spectroscopy (1H-MRS) imaging can be used as a supportive diagnostic tool to differentiate clinically stable brain tumors from those progressing as a result of low- to high-grade malignant transformation or posttherapeutic recurrence. Twenty-seven patients with cerebral gliomas verified on histological examination were studied repeatedly with 1H-MRS imaging over a period of 3.5 years. At the time of each 1H-MRS imaging study, clinical examination, MR imaging, positron emission tomography with 18F-fluorodeoxyglucose, and biopsy findings (when available) were used to categorize each patient as having either stable or progressive disease. Measures of the percentage changes in the choline (Cho) 1H-MRS imaging signal intensity between studies, which were obtained without knowledge of the clinical categorization, allowed the investigators to segregate the groups with a high degree of statistical significance. All progressive cases showed a Cho signal increase between studies of more than 45%, whereas all stable cases showed an elevation of less than 35%, no change, or even a decreased signal. The authors conclude that increased Cho levels coincide with malignant degeneration of cerebral gliomas and therefore may possibly be used as a supportive indicator of progression of these neoplasms.

CvSox-4, the lizard homologue of the human SOX4 gene, shows remarkable conservation among the amniotes

SOX family genes share a high sequence similarity with the HMG box region of the human Y chromosomal gene, SRY. We have cloned and sequenced the HMG box motif of a Sox gene of the lizard, Calotes versicolor. A database search for the cloned sequence, CvSox-4, revealed 100% identity with the SOX4 gene of the human and its homologue in a bird. The result strongly suggests that SOX4 evolved prior to the diversification of amniotes and is highly conserved.

Male-biased distribution of the human Y chromosomal genes SRY and ZFY in the lizard Calotes versicolor, which lacks sex chromosomes and temperature-dependent sex determination

In the present investigation on the lizard Calotes versicolor, which lacks temperature-dependent sex determination, all the conventional cytological techniques used failed to resolve a distinguishable pair of sex chromosomes. However, probing of the genome with the human Y-linked genes SRY and ZFY showed sex-specific bias in their distribution. While the SRY probe hybridized to all the males, more than half of the females examined did not show any hybridization. ZFY hybridized to both the sexes, giving two bands; one was common to all the individuals of both sexes, but the other, of the lower molecular length, occurred in all the males but in less than 50% of females. This predominantly male-specific band is named AMF. The SRY-positive females were also positive for the AMF of ZFY. As positive as well as negative females were fertile and none of the males lacked SRY, it appears that SRY is essential for males only and that both the genes are syntenic in this species. This report raises interesting possibilities on the differentiation of the sex chromosomes in C. versicolor and evolution of SRY/ZFY on the Y chromosome of eutherian mammals through the ancestral group(s) that harbour sex-independent SRY- and ZFY-related genes.

Giant cell arteritis: validity and reliability of various diagnostic criteria

PURPOSE

To ascertain the validity, reliability, sensitivity, and specificity of various signs and symptoms of and diagnostic tests for early diagnosis of giant cell arteritis.

METHODS

From 1973 to 1994, we studied 363 patients who had temporal artery biopsy for suspected giant cell arteritis. All patients underwent detailed clinical evaluation and had erythrocyte sedimentation rates determined; since 1985, 223 patients had their C-reactive protein values estimated. Erythrocyte sedimentation rate and C-reactive protein levels were also estimated in 749 and 138 control subjects, respectively. Signs and symptoms of giant cell arteritis, erythrocyte sedimentation rate, and C-reactive protein levels among patients with positive and negative biopsies were compared.

RESULTS

Of the 363 patients, temporal artery biopsy was positive in 106 and negative in 257. The odds of a positive biopsy were 9.0 times greater with jaw claudication (P < .0001), 3.4 times greater with neck pain (P = .0085), 2.0 times greater with an erythrocyte sedimentation rate of 47 to 107 mm/hour (P = .0454), 3.2 times greater with C-reactive protein above 2.45 mg/dl (P = .0208), and 2.0 times greater for age 75 years or more (P = .0105).

CONCLUSIONS

Clinical criteria most strongly suggestive of giant cell arteritis include jaw claudication, C-reactive protein above 2.45 mg/dl, neck pain, and an erythrocyte sedimentation rate of 47 mm/hour or more, in that order. C-reactive protein was more sensitive (100%) than erythrocyte sedimentation rate (92%) for detection of giant cell arteritis; erythrocyte sedimentation rate combined with C-reactive protein gave the best specificity (97%).

Experiences with ARTEMIS--an Internet-based telemedicine system

ARTEMIS is one of the first systems to exploit the Internet/Intranet technologies for exchanging patient information among health care providers. The primary project goal was to develop and demonstrate a regional telehealth environment specifically to support real-time consultations among health care providers via a computer network, provide secure access to multi-media patient records and discharge summaries, facilitate authentication/digital sign-off, multi-media mail-based referrals, and network-based dictation/transcription. A prototype is deployed in southern West Virginia in a Community Care Network (CCN). The CCN consists of providers, hospitals, clinics, laboratories, that make up one "Virtual" clinic on the "Intranet". ARTEMIS employs new technologies such as Java and JavaScript for the browser, and CORBA-based "middleware" for interoperability at the server-end. Several experiments were designed for evaluating the impact of ARTEMIS on patient care. In this paper we discuss the challenges we faced and the means by which we plan to meet these challenges. We conclude by outlining new thrust areas in which we are concentrating in our next phase of development of ARTEMIS.