Treatment of childhood vulvar lichen sclerosus with potent topical corticosteroid

Potent topical corticosteroid is recognized as the treatment of choice for vulvar lichen sclerosus in adults. A series of 11 children with vulvar lichen sclerosus were treated with the potent topical corticosteroid betamethasone dipropionate 0.05%, seven using an optimized vehicle preparation. There was an excellent response to therapy in all cases. No serious adverse effects or unwanted sequelae occurred. Eight of the 11 children experienced complete remission after 3 months of therapy. In these children no maintenance therapy has been necessary during follow-up periods ranging from 3 to 18 months. Three children required maintenance therapy with a mild topical corticosteroid. We conclude that in children, as in adults, potent topical corticosteroid is a safe and effective treatment for vulvar lichen sclerosus.

NIEHS/EPA Workshops. Growth and differentiation factors

The work group identified a number of research areas where they felt there were significant data gaps where additional research was critical to better under standing of the origins of birth defects and to developing ways for their prevention. These included: 1. Studies designed to determine the role of growth and differentiation factors during pre- and postimplantation stages of development. These investigations could include descriptive studies involving the localization and timing of genes expressed and their products, but must also emphasize and include studies involving the function of these molecules and their interactions in normal and abnormal development. 2. Studies designed to develop and utilize models for investigating normal and abnormal development. These approaches could include in vivo and in vitro techniques, such as creation of genetically defined systems and cell, organ, and whole embryo cultures. These technologies should emphasize ways to study the functions of growth and differentiation factors and the effects of environmental factors. 3. Studies designed to identify environmental agents and their targets in embryonic, extraembryonic, and maternal tissues that may play a role in producing developmental abnormalities through peturbations of growth and differentiation factors. 4. Studies designed to determine cellular and molecular mechanisms for protection and recovery from environmental insults.

Calcium flux through predominantly independent purinergic ATP and nicotinic acetylcholine receptors

Ligand-gated nicotinic acetylcholine receptors (nAChRs) and purinergic ATP receptors are often expressed in the same peripheral and central neurons, and ATP and acetylcholine (ACh) are stored together in some synaptic vesicles. Evidence has suggested that nAChRs and ATP receptors are not independent and that some agonists strongly cross-activate and desensitize both receptor types. Rat sympathetic neurons and nAChRs expressed in Xenopus oocytes were studied to determine the significance of the interactions caused by the two agonist types. Current amplitudes included with separate or combined applications of ATP and nicotine are > 90% additive and independent. Half of all neurons tested responded to either ATP or nicotine but not to both, indicating differences in the expression of the two receptors. In neurons that expressed both receptors types, the nAChRs were inhibited by the activity-dependent open-channel blocker chlorisondamine. If the purinergic and nicotinic receptors were significantly dependent and coactivated, then blocking the ion channels opened by a nicotinic agonist should diminish the current activated by a purinergic agonist. That result was not seen; rather, complete open-channel block of nAChRS with chlorisondamine did not significantly alter the amplitude or kinetics of ATP-induced currents in the same neurons. Finally, when cloned nAChR subunits were expressed in oocytes, ATP activated only very small currents compared with the current activated by Ach. For the 13 different nAChR subunit combinations that were studied, ATP (50-500 microM) activated a current that ranged from 0 to 4% of the size of the current activated by 100 microM ACh. In summary, we find that there is little cross reactivity, and nAChRs and purinergic ATP receptors are predominantly independent, acting with separable physiological characteristics. Therefore the quantitative Ca2+ flux could be separately determined for nAChRs and ATP receptors. The fraction of total current that is carried by Ca2+ was quantitatively determined by simultaneously measuring the whole cell current and the associated change in intracellular Ca2+ with fura-2. For sympathetic neurons bathed in 2.5 mM Ca2+ at a holding potential of -50 mV, Ca2+ carries 4.8 +/- 0.3% (mean +/- SE) of the inward current through neuronal nAChRs and 6.5 +/- 0.1% of the current through purinergic ATP receptors. In conclusion, activity-dependent Ca2+ influx through predominately independent populations of nAChRS and ATP neurons can produce different intracellular signals at purinergic and cholinergic synapses.

Atovaquone for salvage treatment and suppression of toxoplasmic encephalitis in patients with AIDS. Atovaquone/Toxoplasmic Encephalitis Study Group

To examine the efficacy of atovaquone as salvage therapy in patients with AIDS-related toxoplasmic encephalitis, 93 patients with AIDS and toxoplasmic encephalitis who were intolerant of standard therapy (pyrimethamine plus sulfadiazine or clindamycin) or for whom such therapy was failing were treated with atovaquone tablets (750 mg four times daily) for 18 weeks. Plasma levels of atovaquone were measured with high-pressure liquid chromatography, and the clinical and radiological responses and survival were compared according to median plasma concentration groups. During the acute-therapy phase (the first 6 weeks), the conditions of 52% and 37% of the patients, respectively, were clinically or radiologically improved; the conditions of 26% and 15% remained clinically or radiologically improved by week 18. Median survival for all patients was 189 days (Kaplan-Meier estimate). A post-hoc analysis revealed a positive relationship between clinical and radiological responses and median atovaquone plasma concentrations. Survival time among patients with high or medium median steady-state plasma concentrations (319 and 289 days) was significantly better than that among those with low plasma concentrations (114 days; P = .003 and P = .006, respectively).

The acoustic reflex in adults with histories of otitis media in childhood

OBJECTIVE

To investigate the effects of a history of otitis media (OM) in childhood on the acoustic reflex threshold (ART) in young adults.

DESIGN

Questionnaire responses on childhood ear and hearing problems were obtained from populations of university students. In Study 1, 31 students reporting histories of persistent childhood OM and 34 students with no known OM histories were identified. They received pure-tone audiometry, otomicroscopy, and measurement of ARTs for a 500 Hz pure tone. In Study 2, 20 students with OM histories and 20 students with no known OM histories received pure-tone audiometry, otomicroscopy, and measurement of ARTs for a broadband noise.

RESULTS

Subjects with OM histories had higher ARTs than did subjects with no known OM histories. Multiple regression analyses showed that the main variables contributing to elevated reflex thresholds were raised hearing thresholds on the activator ear and tympanic membrane abnormalities on the probe ear.

CONCLUSIONS

The elevated ARTs in adults with histories of childhood OM result from peripheral sequelae of OM. Further evidence is required to determine any functional significance of these raised reflex thresholds.

Macrophage arachidonate release via both the cytosolic Ca(2+)-dependent and -independent phospholipases is necessary for cell spreading

We have observed that phospholipase A2 (PLA2) activation and arachidonate (AA) release are essential for monocyte/macrophage adherence and spreading. In this study, we addressed the relationship between AA release and cell adherence/spreading in murine resident peritoneal macrophages, and the roles of specific PLA2S in these processes. The PLA2-specific inhibitors, (E)-6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one (BEL, specific for the Ca(2+)-independent PLA2 (iPLA2)) and methyl arachidonoyl fluorophosphonate (MAFP, specific for the Ca(2+)-dependent phospholipase (cPLA2)) inhibited AA release and cell spreading in a correlated fashion but only modestly decreased cell adherence. Cell spreading was normalized by the addition of AA to PLA2-inhibited cells. AA release during spreading was also inhibited by Ca2+ depletion or protein kinase C (PKC) inhibition, and was accompanied by increased (but transient) phosphorylation of cPLA2-Inhibition of macrophage spreading, however, only partially inhibited AA release. Moreover, constitutive AA release was seen in fully spread macrophages which was inhibited by BEL, but not MAFP or Ca2+ depletion. BEL also reversed the phenotype of fully spread cells. These data suggest that macrophage spreading requires the release of AA by the iPLA2 (which appears to be constitutively active) and cPLA2 (which appears to be stimulated by adherence/spreading). Maintenance of macrophage spreading, in contrast, appears to be principally dependent on the iPLA2.

Characterization of a prion protein (PrP) gene from rabbit; a species with apparent resistance to infection by prions

The prion protein gene (PrP) encodes a cellular protein of unknown function. A conformational isoform of this protein is involved in the neurodegenerative prion diseases. To facilitate the identification of structurally and antigenically important regions within the PrP molecule, the rabbit PrP open reading frame (ORF) was cloned and characterised. There is 82-87% identity at the nucleotide sequence level and 88-93% identity at the amino acid (aa) sequence level, between the rabbit gene and PrP sequences of other mammals. The rabbit gene shares structural and organisational features common to all known PrP genes signifying that it is the rabbit PrP gene. Comparison of the rabbit PrP aa sequence with PrP aa sequences from different species revealed several potential epitopes. Two anti-ovine PrP peptide Ab raised in rabbits, 168-92 and 98-92, confirmed that two separate cross-reacting epitopes segregate with single aa differences between rabbit and sheep PrP at positions 43 and 99 of the rabbit PrP polypeptide. The presence of these epitopes correlates with the species recognition patterns of previously published Ab. The usefulness of the rabbit PrP gene sequence in predicting antigenic regions within the PrP proteins of various species is illustrated. The structure of the rabbit PrP protein in relation to rabbits apparent resistance to infection by prions is discussed.

Double stapled transabdominal anastomosis for one-stage resection of acute sigmoid volvulus

A double stapling technique is described for the restoration of colonic continuity in patients undergoing sigmoid colectomy for volvulus.

Pregnancy outcome after successful external cephalic version for breech presentation at term

OBJECTIVE

Our purpose was to review the outcome of pregnancies after external cephalic version at term, in particular the incidence and indications of intrapartum cesarean section after successful external cephalic version.

STUDY DESIGN

A prospective study was performed of 241 term pregnancies that had a total of 243 external cephalic versions. Each case with successful external cephalic version was matched to two control cases with cephalic presentation to compare pregnancy outcome.

RESULTS

External cephalic version was successful in 169 attempts (69.5%), of which 7 (4.1%) reverted to breech presentation. There was one case of abruptio placentae and eight cases (3.3%) of transient fetal bradycardia after the procedure. Among those who had a successful external cephalic version, the incidence of intrapartum cesarean section was 16.9%, which was 2.25 times higher than that of the control group (p < 0.005). This large number of abdominal deliveries was due to a significantly higher incidence of fetal distress and dystocic labor. The incidence of augmentation of labor was also significantly higher in the study group (37.7% vs 27.6%, p < 0.05).

CONCLUSION

Pregnancies after a successful external cephalic version at term are not the same as those with cephalic presentation. They are at higher risk of both dystocic labor and fetal distress and therefore require close intrapartum monitoring.

A randomized, double blind, controlled trial of tocolysis to assist external cephalic version in late pregnancy

BACKGROUND

External cephalic version at term is not always successful. This trial was done to ascertain whether tocolysis has any effect on the success rate.

METHODS

A randomized, double blind, controlled trial, with continuous paired sequential analysis. Fifty-one consecutive patients with a singleton fetus in a breech presentation between 36 and 38 weeks gestation, external version being attempted on each. Ritodrine infusion or placebo was infused before attempt at external cephalic version.

SETTING

A university teaching hospital with 8000 confinements annually.

RESULTS

Version was successful in 17 of the 25 patients given tocolysis, but in only eight of the 25 given placebo (p < 0.01). A positive benefit for tocolysis was shown after version had been completed in 10 pairs of patients. However the trial was continued until 25 pairs had been analyzed. The benefit deteriorated during analysis of the last 15 pairs suggesting that the initial benefit may reflect a learning curve for the procedure.

CONCLUSION

Tocolysis is likely to improve the success rate of external cephalic version in late pregnancy, especially in nulliparous mothers or where doctors are learning the technique.

Identification and characterization of the protective hepatocyte erythrocyte protein 17 kDa gene of Plasmodium yoelii, homolog of Plasmodium falciparum exported protein 1

We recently reported the discovery of a 17-kDa Plasmodium yoelii protein expressed in infected hepatocytes and erythrocytes, P. yoelii hepatocyte erythrocyte protein 17 (PyHEP17), and have demonstrated that this protein is a target of protective antibodies and T cells. Here, we report the identification and characterization of the gene encoding this protein and reveal that it is composed of two exons. Immunization of mice with PyHEP17 plasmid DNA induces antibodies, cytotoxic T lymphocytes, and protective immunity directed against the infected hepatocyte. Based on extensive sequence homology, expression pattern, and antigenic cross-reactivity, the Plasmodium falciparum homolog of PyHEP17 is identified as the protein known as exported protein-1 (PfExp-1), also called antigen 5.1, circumsporozoite related antigen, or QF116. Identity between PyHEP17 and PfExp-1 is 37% at the amino acid level (60/161 residues), mapping primarily to two regions within the second exon of 73% (16/22 residues) and 71% (25/35 residues) identity. On this basis, PfExp-1 is proposed as an important component of pre-erythrocytic human malaria vaccines.

Cost-effectiveness of short-course zidovudine to prevent perinatal HIV type 1 infection in a sub-Saharan African Developing country setting

OBJECTIVE

To evaluate the cost-effectiveness of a short-course zidovudine program to prevent perinatal transmission of human immunodeficiency virus (HIV) type 1 in sub-Saharan African country settings.

DESIGN AND SETTING

Several clinical trials of short-course zidovudine during pregnancy for prevention of perinatal transmission of HIV are under way in developing countries in sub-Saharan Africa. A decision model was used to examine the cost-effectiveness of zidovudine programs in a hypothetical 1-year birth cohort in a sub-Saharan African setting from the perspective of the health care system and of society. A completed short course of zidovudine was assumed to reduce perinatal HIV transmission from 25% to 16.5%, approximately one half of the effect of the longer-course zidovudine. Estimates of program costs, lifetime HIV-related health care costs, and lost productivity costs were derived from the published literature and from preliminary data available from sites of planned clinical trials. Sensitivity analyses were conducted on all relevant parameters.

MAIN OUTCOME MEASURES

Medical costs, lost productivity costs, program costs, cost savings, and incremental cost-effectiveness, expressed as cost per infant HIV infection prevented.

RESULTS

The model estimated that a national zidovudine program in a setting with 12.5% HIV seroprevalence would reduce perinatal HIV incidence by 12% (4.9 infections per 1000 births). The costs to the health care system would be $3748 per infant HIV infection prevented. When productivity losses were included in the model, the cost decreases to $1115 per infant HIV infection prevented. The cost to implement a national zidovudine program including the cost of counseling, testing, and drugs, would be $2 million per 100,000 births or $20 per pregnant woman. In the base case, decreases in the cost of counseling and testing and increases in maternal HIV prevalence, zidovudine efficacy, and medical and lost productivity costs improved cost-effectiveness of the zidovudine program.

CONCLUSIONS

Assuming demonstrable efficacy of short-course zidovudine prevention of perinatal HIV, a national perinatal HIV prevention program with zidovudine in most sub-Saharan African country settings would reduce the incidence of infant HIV infection and, in some settings, provide societal savings; however, substantial initial investment in such programs will be required. Where health care resources are limited, as in these regions, allocation of resources to a perinatal zidovudine program will need to be considered in the context of resources required for other pressing medical care needs.

Auditory attentional deficits in patients with schizophrenia. A positron emission tomography study

BACKGROUND

Patients with schizophrenia have frequently been found to perform poorly on tasks requiring selective attention, defined as the ability to focus attention on relevant information while simultaneously ignoring irrelevant stimuli. This study explores the brain mechanisms mediating attentional processing in patients with schizophrenia by measuring their regional cerebral blood flow (rCBF) with positron emission tomography using [15O] water as they performed tasks that differed systematically in attentional demand.

METHODS

Ten schizophrenic patients (either neurolepticnaive or withdrawn from medication) (patient group) and 10 normal volunteers (control group) performed auditory target detection tasks. Different types of auditory stimuli (environmental sounds, meaningless speech sounds, and words) were presented either binaurally (ie, same sounds in both ears) or dichotically (simultaneous and different sounds in the 2 ears). In dichotic conditions, subjects were instructed to focus on either their left or right ear.

RESULTS

Initial subtraction-based image analyses sought significant rCBF changes anywhere in the brain. Patients consistently had less significant activation than controls in right superotemporal gyrus (STG). Follow-up analyses used regions of interest traced on individual magnetic resonance images to precisely measure rCBF in STG. Unlike controls, patients had higher rCBF in the left STG during all activation conditions.

CONCLUSIONS

The abnormal task-related rCBF asymmetry in STG of schizophrenic patients may indicate an isolated temporal lobe deficit, but it may also indicate abnormality in the thalamocortical circuitry mediating selective attention and/or in the brain systems that integrate auditory processing in the 2 hemispheres.

Noradrenaline inhibition of Ca2+ channels and secretion in single patch-clamped insulinoma cells

Noradrenaline effects on voltage-operated calcium channels and exocytosis were studied, for the first time, in single patch-clamped RINm5F insulin-secreting cells. Noradrenaline, despite small and variable inhibition of calcium currents, strongly inhibited the increase in membrane capacitance (a measure of exocytosis) stimulated by both step depolarizations and the calcium ionophore, ionomycin. Noradrenaline similarly inhibited KCl- and ionomycin-induced [3H]serotonin release from RINm5F cell populations. Noradrenaline effects were mediated by PTX-sensitive G proteins. Noradrenaline inhibitory effects on secretion are, therefore, mainly exerted downstream from Ca2+ influx.

A positron emission tomography study of binaurally and dichotically presented stimuli: effects of level of language and directed attention

Regional cerebral blood flow (rCBF) was measured using positron emission tomography with oxygen- 15 labeled water as 10 normal subjects listened to three types of auditory stimuli (environmental sounds, meaningless speech, and words) presented binaurally or dichotically. Binaurally presented environmental sounds and words caused similar bilateral rCBF increases in left and right superior temporal gyri. Dichotically presented stimuli (subjects attended to left or right ears) caused asymmetric activation in the temporal lobes, resulting from increased rCBF in temporal lobe regions contralateral to the attended ear and decreased rCBF in the opposite hemisphere. The results indicate that auditorily presented language and non-language stimuli activate similar temporal regions, that dichotic stimulation dramatically changes rCBF in temporal lobes, and that the change is due both to attentional mechanisms and to hemispheric specialization.

Vision impairment in Liverpool: prevalence and morbidity

A database related to the activities of the Liverpool vision assessment team was used to identify all children with vision impairment aged 0-16 years, resident in Liverpool, UK, on 1 April 1995. Prevalence rates were calculated for all children with vision impairment, and separately for two groups: those with uncomplicated vision impairment, and those with additional pathology. Visual tract pathologies were tabulated and compared. Associated handicapping conditions were defined and the extent of multiple disability was investigated for all vision impaired children, for very low birthweight children, and for those with cortical visual impairment. Of 199 children with vision impairment, 69 (35%) had uncomplicated impairment and 130 (65%) had additional and usually multiple pathology. There were 111 boys (56%); the excess of males was not statistically significant. Prevalence rates per 10,000 population were 18.1 for all vision impairment, 6.3 for uncomplicated vision impairment, and 11.8 for vision impairment complicated by additional pathology. Genetically determined disease accounted for over half the cases of uncomplicated vision impairment. Among the 130 children with additional pathology, cortical visual impairment was the commonest visual tract finding, affecting 64 (49%); 86% had learning difficulties; 53% had cerebral palsy. Multidisability (two or more disabling conditions in addition to vision impairment) affected half the entire childhood vision impairment population. These data should assist health and education authorities to determine the size of the vision impairment problem and how it relates to other disabilities in childhood, and can facilitate resource allocation and service planning.

The influence of glucose tolerance tests on subsequent carbohydrate metabolism in pregnancy

BACKGROUND

This present study was designed to prospectively confirm a previous observational finding that a 75g glucose load exerts an influence on the results of a subsequent 50g glucose tolerance test performed after an interval of one week.

METHODS

Pregnant Chinese patients were given both 50g 3-hour and 75g 2-hour oral glucose tolerance test (OGTT) in random order, 7 days apart, between 28 and 32 weeks of gestation. Patients were divided according to whether they received 50g test first (group 1) or 75g test first (group 2). Student's t-test for independent samples and for paired samples were used for between group comparisons and within patient comparisons respectively using SPSS for Windows software.

RESULTS

Significant decrease in fasting glucose levels (p<0.0001) between paired 50g and 75g OGTT was found when 75g test was performed first. The mean difference in 2-hour values was also 35% lower. Similar results were also found when individual timed glucose levels were compared between groups.

CONCLUSIONS

Differences in the blood glucose levels between OGTTs were confirmed to be related to which glucose load was given first. The 75g test exerts a significant effect on the fasting glucose and the response to a 50g glucose load up to one week later. These effects are consistent with improvement in glucose utilization. The differences observed will not significantly alter current clinical practice but may necessitate modification in the diagnostic crieria of mild abnormal glucose tolerance in pregnancy. We postulate that in some cases of mild glucose intolerance, the response to diet may not be due to caloric reduction but rather stimulation of a previously inadequate insulin response since a proportion of our local pregnant women consistently have calorice intakes significantly below the 1800 kcal per day.

Lichen striatus

Lichen striatus is a self-limiting inflammatory condition of unknown etiology in which the lesions follow the lines of Blaschko. We report a series of 61 cases of this condition in children, describing the clinical features, age distribution, and season of onset. The preponderance of cases in the preschool-age group and onset in the spring and summer months support the hypothesis of an environmental agent, possibly an infection, in the etiology of the condition.

Hair shaft abnormalities: Part II

The clinical and microscopic features are reviewed for trichothiodystrophy, woolly hair, uncombable hair, pili annulati, trichorrhexis invaginata and pseudomonilethrix.

Cloning of the bovine activin receptor type II gene (ACVR2) and mapping to chromosome 2 (BTA2)

The cDNA for the bovine activin receptor type II (ACVR2) gene has been cloned and sequenced. It encodes a protein of 513 amino acids which is highly homologous (approximately 98% identity) to the human, mouse, and rat proteins. Using PCR analysis of bovine x hamster somatic cell lines, the ACVR2 gene was mapped to syntenic group U17, which has been localised to bovine chromosome 2. Comparative mapping has shown that the genes within U17 are also in a syntenic group on the long arm of human and sheep chromosome 2, as well as on mouse chromosome 1. This group of genes represents an evolutionarily conserved mammalian chromosomal segment. Genotyping a highly polymorphic microsatellite locus, (AT)4(GT)9(AT)11, found within an intron of this gene confirmed the localisation by linking the ACVR2-associated microsatellite to the region of chromosome 2 flanked by CSSM42 and TGLA226. This gene locus, which has the characteristics of a type I and type II mapping locus, represents the first localisation of this gene in any species to date.

Unusual electrocardiographic presentation of right ventricular myocardial infarction

Isolated right ventricular infarction is uncommon, but when it occurs its prompt recognition may alter therapy substantially. Electrocardiographic changes accompanying acute right ventricular infarction are variable and may be difficult to recognize. The case of a 40-year-old man who had right ventricular infarction with unusual electrocardiographic findings is presented. The clinical, hemodynamic, and electrocardiographic findings of right ventricular infarction are discussed.