THE NEOPLASTIC POTENTIALITIES OF MOUSE EMBRYO TISSUES : III. THE TUMORS ELICITED FROM GASTRIC EPITHELIUM

Epithelial tumors have been readily obtained by the implantation of embryo stomach tissue together with olive oil containing methylcholanthrene (with or without Scharlach R) in adult mice of homologous strain. The implanted tissue from the squamous portion of the stomach rapidly encysted the oil, and benign and malignant papillomas and squamous cell carcinomas soon arose from the stratified squamous lining of the cysts. Bits of the glandular portion of the stomach also formed cysts, but the gland cells underwent metaplasia in response to the carcinogen, altering first to transitional epithelium and then to a stratified squamous layer. So swiftly did these changes take place that nearly all of the tumors took origin from epithelium that had already become stratified and squamous, and the growths themselves were of this type. A single transitional cell carcinoma and an adenoacanthoma were procured, but no adenocarcinomas; nor did any benign papillomas develop, though they often resulted from the action of methylcholanthrene on the squamous portion of the embryo stomach. Search failed to disclose any distinctive precancerous changes in the gastric tissue. Five of the cancers were transplanted and they grew in every host. No tumors arose from any of the numerous control implants. Those consisting of glandular tissue formed cysts lined partly with columnar epithelium secreting mucus and partly with tubular glands equipped with chief and parietal cells in good condition. Pepsin and rennin were found in the fluid contained in these cysts, but no free hydrochloric acid. The enzymes were present also when the cysts contained methylcholanthrene and the glands had not yet been wholly replaced by metaplastic epithelium. The tumors appeared months sooner than when methylcholanthrene is injected into the stomach of adult animals or given by mouth; some of them were well established after 5 or 6 weeks. They arose regularly when the requisite experimental conditions were provided. The utilization of transplanted embryo tissue provides a means whereby gastric tumors free from bacterial infection can be procured swiftly and easily.

THE NEOPLASTIC POTENTIALITIES OF MOUSE EMBRYO TISSUES : I. THE FINDINGS WITH SKIN OF C STRAIN EMBRYOS TRANSPLANTED TO ADULT ANIMALS

A method has been devised whereby the transplanted epidermis of mouse embryos can be selectively exposed to the action of a chemical carcinogen. Scharlach R was dissolved in olive oil with the aim of stimulating and attracting the epidermal cells, methylcholanthrene was added to the solution, and numerous fine globules of it were injected into the thigh muscles of adult mice together with fragments of embryo skin. Much of the oil underwent primary inclusion in the resulting cysts, and the proliferating epidermis, while forming them, extended to not a few of the outlying droplets with result that they too were added to the cyst contents. During these activities the methylcholanthrene came into direct contact with many of the epithelial cells, and later on the layer lining the cyst was continually exposed to the influence of the carcinogen. The epidermis underwent neoplastic changes with great rapidity; often in less than 4 weeks papillomas and carcinomas had arisen like those deriving from adult epidermis. The growths were punctate in origin and usually multiple. Many were transplanted to adults of the same homologous breed of mice that furnished the embryo material (mice of C strain). The grafts did not uniformly succeed as was the case with those of normal skin of embryos of the same stock,-which regularly grew at first in the new hosts and remained alive long after. The benign papillomas failed to live or barely survived, and the apparently malignant papillomas, though rapidly forming nodules of considerable size, usually regressed later. Some of the carcinomas also regressed or wholly failed, while others gave rise to progressively enlarging tumors. The best results were obtained with grafts in which several neoplasms were intermingled, these flourishing together in the new hosts. Methylcholanthrene in olive oil exerts an influence on epidermal cells like that of Scharlach R, stimulating them to multiply, attracting them, and causing them to mimic carcinomatous elements.

THE NEOPLASTIC POTENTIALITIES OF MOUSE EMBRYO TISSUES : II. CONTRIBUTORY EXPERIMENTS; RESULTS WITH THE SKIN OF C3H AND WEBSTER-SWISS EMBRYOS; GENERAL CONSIDERATIONS

Experiments were carried out to learn whether the widely differing liabilities to induced epidermal tumors of individual mice and rabbits are due to a previous localization out of the blood of an agent capable of undergoing change when the skin is exposed to carcinogenic influences, and of producing tumors in consequence. On the assumption that such an agent would localize in increased quantity where cutaneous inflammation exists, like various inert substances of large molecule and the epidermotrophic viruses when circulating, skin areas on adult and new-born animals were for some weeks kept inflamed, and months later, when the areas appeared normal, methylcholanthrene was applied to them and to control areas on the same or other individuals. No differences were observable in tumor incidence. These results led to attempts to test whether embryo epidermis is capable of undergoing neoplastic change, and the work of Paper I was done which showed that epidermal tumors arise with great rapidity and regularity from embryo skin transplanted to adults of homologous strain (C strain) together with methylcholanthrene. Webster-Swiss mice proved unsuited to experiments of the sort owing to heterogeneity of the breed, the transplanted embryo skin dying in most instances before the methylcholanthrene introduced with it could have been carcinogenic. The skin of C3H embryos also did badly, as if from incompatibility in some instances but mostly because its epidermal cells proliferated less vigorously than those of C embryos and did not tolerate methylcholanthrene nearly so well. Despite these difficulties, epidermal tumors were occasionally induced, as also in the transplanted skin of Webster-Swiss embryos, and the growths appeared quite soon, all things considered. The effect of methylcholanthrene on the skin of sucklings, their mothers, and young adult mice of the C strain was studied in order to find out whether the rapid rate of neoplastic change in the transplanted epidermis of embryos is indicative of some liability connected with its period of development. The skin of new-born animals proved very refractory to the carcinogen, hair coming in at the same rate as on control litters and no perceptible inflammation occurring for about 2 weeks, although within this period the mothers of the treated animals and the young adults became hairless where the methylcholanthrene had been put and their skin was much inflamed. Later on, as the applications were kept up, similar changes took place in the sucklings, but none of these developed tumors during some 6 weeks of observation whereas growths appeared within 3 weeks on more than half of the mother mice and on some of the young adults. The failure to produce tumors in the sucklings seems to have been due to cutaneous conditions preventing the necessary exposure of the deeper epidermal cells to methylcholanthrene. In any projected correlation of age differences with the response of cells to carcinogens allowance must be made for such factors. The present findings give no ground for the supposition that embryo skin has any special liability to neoplastic change. The results of transferring the tumors derived from embryo epidermis to new hosts have made plain that the neoplastic state not infrequently entails disabilities which are crucial, the tumor cells failing to succeed unless aided. This holds true of some carcinomas as well as of papillomas. By transplanting pieces of the organs of C embryos together with methylcholanthrene tumors of many sorts besides the epidermal have been obtained. As yet only those of the stomach have been worked with extensively. They can be elicited as quickly and regularly as those of the epidermis and can be as easily transplanted. The findings as a whole render it impossible to suppose that the neoplastic potentialities possessed by transplanted embryo tissues are due to the lodgement in them of tumor-producing viruses as specialized in their effects as those now known, or of precursor agents conferring neoplastic liabilities specialized to the same degree. Some other possibilities are mentioned. The rarity of neoplasms at birth is due to the circumstances of intrauterine life and to its brevity, not to any lack of capacity of the cells of the embryo to undergo neoplastic change.

Psychiatric features in children with genetic syndromes: toward functional phenotypes

Neurodevelopmental disorders with identified genetic etiologies present a unique opportunity to study gene-brain-behavior connections in child psychiatry. Parsing complex human behavior into dissociable components is facilitated by examining a relatively homogenous genetic population. As children with developmental delay carry a greater burden of mental illness than the general population, familiarity with the most common genetic disorders will serve practitioners seeing a general child population. In this article basic genetic testing and 11 of the most common genetic disorders are reviewed, including the evidence base for treatment. Based on their training in child development, family systems, and multimodal treatment, child psychiatrists are well positioned to integrate cognitive, behavioral, social, psychiatric, and physical phenotypes, with a focus on functional impairment.

Sibling phenotype concordance in classical infantile Pompe disease

Pompe disease (acid-alpha-glucosidase deficiency) encompasses a clinical spectrum, ranging from severe infantile-onset disease with clinical symptoms appearing before 1 year of age with rapid progression to an early death, to late-onset disease with a much more variable age at onset and disease course. Sibling phenotype discordance has been reported for late-onset Pompe disease, but has not been studied in classical infantile disease. We reviewed the medical literature for affected sibships in which at least one sibling had clinical and pathology or biochemical findings consistent with infantile Pompe disease including symptoms beginning in infancy, early hypotonia, cardiomegaly documented by 6 months of age, and early death. The age at symptom onset, age at death, and clinical course were compared between probands and affected siblings. Our results showed that since 1931, publications document 13 families with 31 affected infants (11 probands; 20 affected siblings). The median age at symptom onset for all affected infants was 3 months (range 0-6 months) with significant correlation (R = 0.60, P = 0.04) between probands and affected siblings. The median age at death for all affected infants was 6 months (range 1.5-13 months); probands were slightly older at death than their siblings. The median length of disease course for all affected infants was 3 months (0-10 months) and was slightly longer for probands. Unlike late-onset Pompe disease, there appears to be minimal phenotypic and lifespan variation among siblings with infantile Pompe disease. This prognostic information is vital for families with affected infants and allows for appropriate genetic counseling.

Practical control of SERRS enhancement

The demonstration that quantitative and sensitive analysis can be carried out using surface enhanced resonance Raman scattering (SERRS) prompted a discussion and investigation of the main variables which are within the control of the analyst using colloidal silver as the substrate. Previous papers have dealt with the crucial need to obtain good chemisorption of the analyte to the surface and have reported the use of specially designed dyes for SERRS. One of the most variable processes is the aggregation of the colloid. Here, we investigate the addition of controlled amounts of an organic aggregating agent, poly-L-lysine, at concentrations which reduce the zeta potential in a controlled manner, thus aiding aggregation control. The relationship between the excitation frequency, the surface plasmon resonance frequency of the silver colloid and the frequency of the maximum absorbance of the molecular chromophore is studied using low concentrations of dye and no aggregating agent. Under these conditions, little to no aggregation is expected. The magnitude of the enhancement is strongly dependent on the frequency of the molecular chromophore as well as the plasmon resonance frequency. However, when sodium chloride is used to aggregate the colloid, a larger enhancement is obtained and the strong dependence on the molecular chromophore largely disappears. A much broader enhancement profile is obtained which appears to be related more to the specific enhancement processes caused by aggregation than the frequency of the chromophore. However, the total enhancement for SERRS is higher than for SERS thus indicating that the chromophore is still important to the process.

TBX5 genetic testing validates strict clinical criteria for Holt-Oram syndrome

Holt-Oram syndrome (HOS) is an autosomal dominant heart-hand syndrome characterized by congenital heart disease (CHD) and upper limb deformity, and caused by mutations in the TBX5 gene. To date, the sensitivity of TBX5 genetic testing for HOS has been unclear. We now report mutational analyses of a nongenetically selected population of 54 unrelated individuals who were consecutively referred to our center with a clinical diagnosis of HOS. TBX5 mutational analyses were performed in all individuals, and clinical histories and findings were reviewed for each patient without reference to the genotypes. Twenty-six percent of the complete cohort was shown to have mutations of the TBX5 gene. However, among those subjects for whom clinical review demonstrated that their presentations met strict diagnostic criteria for HOS, TBX5 mutations were identified in 74%. No mutations were identified in those subjects who did not meet these criteria. Thus, these studies validate our clinical diagnostic criteria for HOS including an absolute requirement for preaxial radial ray upper limb malformation. Accordingly, TBX5 genotyping has high sensitivity and specificity for HOS if stringent diagnostic criteria are used in assigning the clinical diagnosis.

Metabolic evaluation of the sick neonate

Inherited metabolic diseases are rare causes of neonatal morbidity, but they are associated with significant recurrence risks for the parents. Prompt identification and treatment of an infant with an inherited metabolic disease can minimize morbidity, mortality, and lifelong developmental problems. Diagnosis often requires specialized laboratory testing, but common laboratory tests can help identify those infants needing further evaluation. This paper reviews the laboratory abnormalities which can be found in various inherited metabolic diseases and can guide selection of specialized metabolic testing. Consultation with a metabolic specialist is essential for timely diagnosis and treatment to ensure the best possible outcome.

Three-dimensional optical trapping of partially silvered silica microparticles

We demonstrate three-dimensional trapping of micrometer-diameter silica particles, partially coated with silver, within conventional optical tweezers. Although metallic particles are usually repelled from the beam focus by the scattering force, we show that transparent spheres partially coated with silver can be trapped with efficiencies comparable with dielectric particles. The trapping characteristics of these particles are examined as a function of metallic coverage, and the application of these particles to surface-enhanced resonance Raman scattering is investigated.

Characterization of novel Ag on TiO2 films for surface-enhanced Raman scattering

Novel Ag on TiO2 films are generated by semiconductor photocatalysis and characterized by ultraviolet-visible (UV/Vis) spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM), as well as assessed for surface-enhanced Raman scattering (SERS) activity. The nature and thickness of the photodeposited Ag, and thus the degree of SERS activity, is controlled by the time of exposure of the TiO2 film to UV light. All such films exhibit the optical characteristics (lambda(max) congruent with 390 nm) of small (< 20 nm) Ag particles, although this feature becomes less prominent as the film becomes thicker. The films comprise quite large (> 40 nm) Ag islands that grow and merge with increasing levels of Ag photodeposition. Tested with a benzotriazole dye probe, the films are SERS active, exhibiting activity similar to that of 6-nm-thick vapor-deposited films. The Ag/TiO2 films exhibit a lower residual standard deviation (approximately 25%) compared with Ag vapor-deposited films (approximately 45%), which is, however, still unacceptable for quantitative work. The sample-to-sample variance could be reduced significantly (< 7%) by spinning the film during the SERS measurement. The Ag/TiO2 films are mechanically robust and resistant to removal and damage by scratching, unlike the Ag vapor-deposited films. The Ag/TiO2 films also exhibit no obvious loss of SERS activity when stored in the dark under otherwise ambient conditions. The possible extension of this simple, effective method of producing Ag films for SERS, to metals other than Ag and to semiconductors other than TiO2, is briefly discussed.

Resonance Raman scattering of cytochrome P450 BM3 and effect of imidazole inhibitors

Resonance Raman scattering from cytochrome P450 BM3 is obtained with a Raman microprobe using 406-nm excitation with an accumulation time of a few seconds. The small sample size and rapid measurement time make the routine characterization of P450 systems by resonance Raman spectroscopy easier. Addition of imidazole and imidazole derivatives as inhibitors causes the appearance of additional peaks due to vinyl modes, increases the relative intensity of symmetric modes that would be A(1g) in D(4h) symmetry, and causes a large drop in the intensity of nu(11). This information indicates that the ligation of imidazoles to the heme iron causes the alignment of the vinyl modes with the plane of the heme ring and reduces the out of plane distortion of the ring. The effect of both inhibitors is similar but there is a subtle difference in the extent of the reduction in the intensity of nu(11), which suggests that steric effects within the pocket are having some effect.

Microduplication 22q11.2, an emerging syndrome: clinical, cytogenetic, and molecular analysis of thirteen patients

Chromosome 22, particularly band 22q11.2, is predisposed to rearrangements due to misalignments of low-copy repeats (LCRs). DiGeorge/velocardiofacial syndrome (DG/VCFS) is a common disorder resulting from microdeletion within the same band. Although both deletion and duplication are expected to occur in equal proportions as reciprocal events caused by LCR-mediated rearrangements, very few microduplications have been identified. We have identified 13 cases of microduplication 22q11.2, primarily by interphase fluorescence in situ hybridization (FISH). The size of the duplications, determined by FISH probes from bacterial artificial chromosomes and P(1) artificial chromosomes, range from 3-4 Mb to 6 Mb, and the exchange points seem to involve an LCR. Molecular analysis based on 15 short tandem repeats confirmed the size of the duplications and indicated that at least 1 of 15 loci has three alleles present. The patients' phenotypes ranged from mild to severe, sharing a tendency for velopharyngeal insufficiency with DG/VCFS but having other distinctive characteristics, as well. Although the present series of patients was ascertained because of some overlapping features with DG/VCF syndromes, the microduplication of 22q11.2 appears to be a new syndrome.

Surface-enhanced resonance Raman scattering of black inkjet dyes in solution and in situ printed onto paper

Understanding the changes that occur when dyes are absorbed onto paper is crucial for the design of new inkjet dyes. This problem is particularly difficult for black dyes that have complex chromophores, and as a result, spectroscopic information on electronic and structural changes can be of importance. Surface-enhanced resonance Raman scattering (SERRS) and electronic structure calculations were used to probe in situ changes in the chromophore in black di-azo dyes printed onto paper. The data indicate that the low-energy chromophore is due mainly to the hydrazone group and the high-energy chromophore to both the azo and hydrazone groups. A comparison of SERRS from the dyes adsorbed onto silver particles in suspension and from the dyes on paper demonstrated a broadening of the chromophore into the red for both dyes and evidence of a structural change in one dye.

Rare disorders of metabolism with elevated butyryl- and isobutyryl-carnitine detected by tandem mass spectrometry newborn screening

Tandem mass spectrometry was adopted for newborn screening by North Carolina in April 1999. Since then, three infants with short-chain acyl-CoA dehydrogenase (SCAD) and one with isobutyryl-CoA dehydrogenase deficiency were detected on the basis of elevated butyrylcarnitine/isobutyrylcarnitine (C4-carnitine) concentrations in newborn blood spots analyzed by tandem mass spectrometry. For three SCAD-deficient infants, biochemical evaluation included a plasma acylcarnitine profile with markedly elevated C4-carnitine, urine organic acid analysis with markedly elevated ethylmalonic and 2-methylsuccinic acids, and markedly elevated [U-13C]butyrylcarnitine concentrations in medium from fibroblasts incubated with [U-13C]palmitic acid and excess l-carnitine, consistent with classic SCAD deficiency. Two of three infants diagnosed with classic SCAD deficiency remained asymptomatic; however, the third infant presented with seizures and a cerebral infarct at 10 wk of age. All three infants had putatively inactivating mutations in both alleles of the SCAD gene. The highly elevated plasma C4-carnitine levels in the three infants detected by newborn screening tandem mass spectrometry differentiated them from infants and children who were homozygous or compound heterozygous for one of two SCAD gene susceptibility variations; for the latter group the C4-carnitine levels were normal. Isobutyryl-CoA dehydrogenase deficiency in a fourth infant was confirmed after isolated elevation of C4-carnitine in the acylcarnitine profile.

Shiga toxin 1 triggers a ribotoxic stress response leading to p38 and JNK activation and induction of apoptosis in intestinal epithelial cells

Shiga toxins made by Shiga toxin-producing Escherichia coli (STEC) are associated with hemolytic uremic syndrome. Shiga toxins (Stxs) may access the host systemic circulation by absorption across the intestinal epithelium. The effects of Stxs on this cell layer are not completely understood, although animal models of STEC infection suggest that, in the gut, Stxs may participate in both immune activation and apoptosis. Stxs have one enzymatically active A subunit associated with five identical B subunits. The A subunit inactivates ribosomes by cleaving a specific adenine from the 28S rRNA. We have previously shown that Stxs can induce multiple C-X-C chemokines in intestinal epithelial cells in vitro, including interleukin-8 (IL-8), and that Stx-induced IL-8 expression is linked to induction of c-Jun mRNA and p38 mitogen-activated protein (MAP) kinase pathway activity. We now report Stx1 induction of both primary response genes c-jun and c-fos and activation of the stress-activated protein kinases, JNK/SAPK and p38, in the intestinal epithelial cell line HCT-8. By 1 h of exposure to Stx1, mRNAs for c-jun and c-fos are induced, and both JNK and p38 are activated; activation of both kinases persisted up to 24 h. Stx1 enzymatic activity was required for kinase activation; a catalytically defective mutant toxin did not activate either. Stx1 treatment of HCT-8 cells resulted in cell death that was associated with caspase 3 cleavage and internucleosomal DNA fragmentation; this cytotoxicity also required Stx1 enzymatic activity. Blocking Stx1-induced p38 and JNK activation with the inhibitor SB202190 prevented cell death and diminished Stx1-associated caspase 3 cleavage. In summary, these data link the Stx1-induced ribotoxic stress response with both chemokine expression and apoptosis in the intestinal epithelial cell line HCT-8 and suggest that blocking host cell MAP kinases may prevent these Stx-associated events.

Analysis of thin film coatings on poly(ethylene terephthalate) by confocal Raman microscopy and surface-enhanced Raman scattering

The characterization of thin coatings on polymers such as poly(ethylene terephthalate) (PET) is required in order to study chemical composition and coating continuity. Two different methods of applying Raman spectroscopy for this purpose are compared in this paper. Using confocal Raman microscopy, thick coatings (> 10 microns) are relatively easily identified; however, the Raman scattering from the acrylic coatings commonly used is much weaker than that of PET and consequently, there is a background due to the substrate. Thin acrylic coatings (< 1 micron) usually cannot be detected. Surface-enhanced Raman scattering (SERS) of uncoated PET gives intense signals and if the spectra are taken from the metal-coated side, there is no evidence of the underlying Raman scattering from the bulk. Acrylic coatings do not give sufficiently strong or reproducible SERS to be reliably identified, but even thin (20 nm) coatings completely block the SERS from the substrate. Only where gaps appear in the coating is the SERS of the underlying PET seen. To detect a positive signal from the coating, SERS active labels were incorporated into the acrylic at low concentrations either as a physical mixture or as reactive co-monomers. This uniquely labels the coating and allows detection and, in principle, mapping of the coverage. Thus, for thick (> > 1 micron) coatings, normal Raman spectroscopy is an effective technique for detecting the presence of the surface coating. However, it is ineffective with thin (< 1 micron) coatings, and SERS alone only indicates where the coating is incomplete or defective. However, when a SERS label is added, spectra can be detected from very thin coatings (20 nm). The concentration of the labels is sufficiently low for the coating to remain colorless.

Evaluation of 3-methylcrotonyl-CoA carboxylase deficiency detected by tandem mass spectrometry newborn screening

Since the addition of tandem mass spectrometry (MS/MS) to the North Carolina Newborn Screening Program, 20 infants with two consecutive elevated 3-hydroxyisovalerylcarnitine (C5OH) levels have been evaluated for evidence of inborn errors of metabolism associated with this metabolite. Ten of these 20 infants had significant concentrations of both 3-hydroxyisovaleric acid and 3-methylcrotonylglycine in their urine, suggestive of 3-methylcrotonyl-CoA carboxylase (3-MCC) deficiency. Four of these 10 were infants whose abnormal metabolites were found to be of maternal origin. Of 8 patients with probable 3-MCC deficiency, 7 have been tested and found to have the enzyme deficiency confirmed in lymphoblasts or cultured fibroblasts; one of these 7 infants had only marginally decreased 3-MCC activity in lymphocytes but deficient 3-MCC in fibroblasts. We estimate the incidence of 3-MCC deficiency at 1:64000 live births in North Carolina. We conclude that MS/MS newborn screening will detect additional inborn errors of metabolism, such as 3-MCC deficiency, not traditionally associated with newborn screening. The evaluation of newborns with two abnormally elevated C5OH levels on MS/MS newborn screening should include, at least, urine organic acid analysis by capillary GC-MS and a plasma acylcarnitine profile by MS/MS. Long-term follow-up is needed to determine the outcome of presymptomatically diagnosed patients with 3-MCC deficiency by MS/MS newborn screening.

Assessment of silver and gold substrates for the detection of amphetamine sulfate by surface enhanced Raman scattering (SERS)

Methods of detection of amphetamine sulfate using surface enhanced Raman scattering (SERS) from colloidal suspensions and vapour deposited films of both silver and gold are compared. Different aggregating agents are required to produce effective SERS from silver and gold colloidal suspensions. Gold colloid and vapour deposited gold films give weaker scattering than the equivalent silver substrates when high concentrations of drug are analysed but they also give lower detection limits, suggesting a smaller surface enhancement but stronger surface adsorption. A 10(-5) mol dm(-3) solution (the final concentration after addition of colloid was 10(-6) mol dm(-3)) of amphetamine sulfate was detected from gold colloid with an RSD of 5.4%. 25 microl of the same solution could be detected on a roughened gold film. The intensities of the spectra varied across the film surface resulting in relatively high RSDs. The precision was improved by averaging the scattering from several points on the surface. An attempt to improve the detection limit and precision by concentrating a suspension of gold colloid and amphetamine sulfate in aluminium wells did not give effective quantitation. Thus, positive identification and semi-quantitative estimation of amphetamine sulfate can be made quickly and easily using SERS from suspended gold colloid with the appropriate aggregating agents.

Shiga toxins induce, superinduce, and stabilize a variety of C-X-C chemokine mRNAs in intestinal epithelial cells, resulting in increased chemokine expression

Exposure of humans to Shiga toxins (Stxs) is a risk factor for hemolytic-uremic syndrome (HUS). Because Stx-producing Escherichia coli (STEC) is a noninvasive enteric pathogen, the extent to which Stxs can cross the host intestinal epithelium may affect the risk of developing HUS. We have previously shown that Stxs can induce and superinduce IL-8 mRNA and protein in intestinal epithelial cells (IECs) in vitro via a ribotoxic stress response. We used cytokine expression arrays to determine the effect of Stx1 on various C-X-C chemokine genes in IECs. We observed that Stx1 induces multiple C-X-C chemokines at the mRNA level, including interleukin-8 (IL-8), GRO-alpha, GRO-beta, GRO-gamma, and ENA-78. Like that of IL-8, GRO-alpha and ENA-78 mRNAs are both induced and superinduced by Stx1. Furthermore, Stx1 induces both IL-8 and GRO-alpha protein in a dose-response fashion, despite an overall inhibition in host cell protein synthesis. Stx1 treatment stabilizes both IL-8 and GRO-alpha mRNA. We conclude that Stxs are able to increase mRNA and protein levels of multiple C-X-C chemokines in IECs, with increased mRNA stability at least one mechanism involved. We hypothesize that ribotoxic stress is a pathway by which Stxs can alter host signal transduction in IECs, resulting in the production of multiple chemokine mRNAs, leading to increased expression of specific proteins. Taken together, these data suggest that exposing IECs to Stxs may stimulate a proinflammatory response, resulting in influx of acute inflammatory cells and thus contributing to the intestinal tissue damage seen in STEC infection.

Hepatic storage of glycogen in Niemann-Pick disease type B

We report 2 patients with confirmed Niemann-Pick disease, type B, with previous diagnoses of glycogen storage disease based on excessive glycogen on liver biopsy specimens. These cases emphasize the importance of a complete evaluation, including biochemical confirmation, for patients with suspected metabolic storage diseases.

Glutaric acidemia, type I, missed by newborn screening in an infant with dystonia following promethazine administration

We report a child initially diagnosed with promethazine-induced dystonia despite a lack of response to diphenhydramine therapy. On further evaluation, the child was diagnosed with glutaric acidemia, type I (GA-I), an autosomal recessive inborn error of metabolism caused by the deficiency of glutaryl-CoA dehydrogenase. The characteristic clinical feature of GA-I is an acute encephalopathic and neurologic crisis typically occurring during a catabolic state. Despite slow improvement, many patients do not fully recover from a neurologic crisis, and residual neurologic morbidity can be significant. Although newborn screening using tandem mass spectrometry is expected to enable presymptomatic diagnosis of GA-I, this patient was not detected by newborn screening with tandem mass spectrometry. Therefore, a high suspicion of GA-I must be maintained in the evaluation of childhood dystonia, even when newborn screening results are reportedly normal.