Dimethylformamide dimethyl acetal reagent for in situ chiral analyses of organic molecules on Titan with the Dragonfly mass spectrometer space instrument (Dragonfly mission)

Thanks to the Cassini-Huygens space mission between 2004 and 2017, a lot was learned about Titan, the biggest satellite of Saturn, and its intriguing atmosphere, surface, and organic chemistry complexity. However, key questions about the potential for the atmosphere and surface chemistry to produce organic molecules of direct interest for prebiotic chemistry and life did not find an answer. Due to Titan potential as a habitable world, NASA selected the Dragonfly space mission to be launched in 2027 to Titan's surface and explore the Shangri-La surface region for minimum 3 years. One of the main goals of this mission will be to understand the past and actual abundant prebiotic chemistry on Titan, especially using the Dragonfly Mass Spectrometer (DraMS). Two recently used sample pre-treatments for Gas Chromatography - Mass Spectrometry (GC-MS mode of DraMS) analyses are planned prior analysis to extract refractory organic molecules of interest for prebiotic chemistry and astrobiology. The dimethylformamide dimethylacetal (DMF-DMA) derivatization reaction offers undoubtedly an opportunity to detect biosignatures by volatilizing refractory biological or prebiotic molecules and conserving the chiral carbons' conformation while an enantiomeric excess indicates a chemical feature induced primarily by life (and may be aided on the primitive systems by light polarization). The goal of this study is to investigate the ageing of DMF-DMA in DraMS (and likely MOMA) capsules prior to in situ analysis on Titan (or Mars). The main results highlighted by our work on DMF-DMA are first its satisfactory stability for space requirements through time (no significant degradation over a year of storage and less than 30 % of lost under thermal stress) to a wide range of temperature (0 °C to 250 °C), or the presence of water and oxidants during the derivatization reaction (between 0 and 10 % of DMF-DMA degradation). Moreover, this reagent derivatized very well amines and carboxylic acids in high or trace amounts (ppt to hundreds of ppm), conserving their molecular conformation during the heat at 145 °C for 3 min (0 to 4% in the enantiomeric form change).

Splicing factor Prp18p promotes genome-wide fidelity of consensus 3'-splice sites

The fidelity of splice site selection is critical for proper gene expression. In particular, proper recognition of 3'-splice site (3'SS) sequences by the spliceosome is challenging considering the low complexity of the 3'SS consensus sequence YAG. Here, we show that absence of the Prp18p splicing factor results in genome-wide activation of alternative 3'SS in S. cerevisiae, including highly unusual non-YAG sequences. Usage of these non-canonical 3'SS in the absence of Prp18p is enhanced by upstream poly(U) tracts and by their potential to interact with the first intronic nucleoside, allowing them to dock in the spliceosome active site instead of the normal 3'SS. The role of Prp18p in 3'SS fidelity is facilitated by interactions with Slu7p and Prp8p, but cannot be fulfilled by Slu7p, identifying a unique role for Prp18p in 3'SS fidelity. This fidelity function is synergized by the downstream proofreading activity of the Prp22p helicase, but is independent from another late splicing helicase, Prp43p. Our results show that spliceosomes exhibit remarkably relaxed 3'SS sequence usage in the absence of Prp18p and identify a network of spliceosomal interactions centered on Prp18p which are required to promote the fidelity of the recognition of consensus 3'SS sequences.

Influence of pH and salts on DMF-DMA derivatization for future Space Applications

For gas chromatography - mass spectrometry (GC-MS) analyses performed in situ, pH and salts (e.g., chlorides, sulfates) may enhance or inhibit the detection of targeted molecules of interest for astrobiology (e.g. amino acids, fatty acids, nucleobases). Obviously, salts influence the ionic strength of the solutions, the pH value, and the salting effect. But the presence of salts may also produce complexes or mask ions in the sample (masking effect on hydroxide ion, ammonia, etc.). For future space missions, wet chemistry will be conducted before GC-MS analyses to detect the full organic content of a sample. The defined organic targets for space GC-MS instrument requirements are generally strongly polar or refractory organic compounds, such as amino acids playing a role in the protein production and metabolism regulations for life on Earth, nucleobases essential for DNA and RNA formation and mutation, and fatty acids that composed most of the eukaryote and prokaryote membranes on Earth and resist to environmental stress long enough to still be observed on Mars or ocean worlds in geological well-preserved records. The wet-chemistry chemical treatment consists of reacting an organic reagent with the sample to extract and volatilize polar or refractory organic molecules (i.e. dimethylformamide dimethyl acetal (DMF-DMA) in this study). DMF-DMA derivatizes functional groups with labile H in organics, without modifying their chiral conformation. The influence of pH and salt concentration of extraterrestrial materials on the DMF-DMA derivatization remains understudied. In this research, we studied the influence of different salts and pHs on the derivatization of organic molecules of astrobiological interest with DMF-DMA, such as amino acids, carboxylic acids, and nucleobases. Results show that salts and pH influence the derivatization yield, and that their effect depend on the nature of the organics and the salts studied. Second, monovalent salts lead to a higher or similar organic recovery compared to divalent salts regardless of pH below 8. However, a pH above 8 inhibits the DMF-DMA derivatization influencing the carboxylic acid function to become an anionic group without labile H. Overall, considering the negative effect of the salts on the detection of organic molecules, future space missions may have to consider a desalting step prior to derivatization and GC-MS analyses.

Spliceosomal mutations decouple 3' splice site fidelity from cellular fitness

The fidelity of splice site selection is thought to be critical for proper gene expression and cellular fitness. In particular, proper recognition of 3'-splice site (3'SS) sequences by the spliceosome is a daunting task considering the low complexity of the 3'SS consensus sequence YAG. Here we show that inactivating the near-essential splicing factor Prp18p results in a global activation of alternative 3'SS, many of which harbor sequences that highly diverge from the YAG consensus, including some highly unusual non-AG 3'SS. We show that the role of Prp18p in 3'SS fidelity is promoted by physical interactions with the essential splicing factors Slu7p and Prp8p and synergized by the proofreading activity of the Prp22p helicase. Strikingly, structure-guided point mutations that disrupt Prp18p-Slu7p and Prp18p-Prp8p interactions mimic the loss of 3'SS fidelity without any impact on cellular growth, suggesting that accumulation of incorrectly spliced transcripts does not have a major deleterious effect on cellular viability. These results show that spliceosomes exhibit remarkably relaxed fidelity in the absence of Prp18p, and that new 3'SS sampling can be achieved genome-wide without a major negative impact on cellular fitness, a feature that could be used during evolution to explore new productive alternative splice sites.

Protocol for High-Resolution Mapping of Splicing Products and Isoforms by RT-PCR Using Fluorescently Labeled Primers

We describe an RT-PCR protocol that allows high-resolution mapping of splicing products and isoforms using fluorescently labeled primers. Each species contains one fluorescent group allowing a direct comparison of the different isoforms despite size differences. A custom-size ladder enables the precise determination of cDNA lengths and discrimination of isoforms differing by less than five nucleotides on polyacrylamide gels. This protocol also allows the detection of products from in vitro splicing reactions, circumventing the need to use radiolabeled transcripts. For complete details on the use and execution of this protocol, please refer to Gabunilas and Chanfreau (2016).

BC200 (BCYRN1) - The shortest, long, non-coding RNA associated with cancer

With the discovery that the level of RNA synthesis in human cells far exceeds what is required to express protein-coding genes, there has been a concerted scientific effort to identify, catalogue and uncover the biological functions of the non-coding transcriptome. Long, non-coding RNAs (lncRNAs) are a diverse group of RNAs with equally wide-ranging biological roles in the cell. An increasing number of studies have reported alterations in the expression of lncRNAs in various cancers, although unravelling how they contribute specifically to the disease is a bigger challenge. Originally described as a brain-specific, non-coding RNA, BC200 (BCYRN1) is a 200-nucleotide, predominantly cytoplasmic lncRNA that has been linked to neurodegenerative disease and several types of cancer. Here we summarise what is known about BC200, primarily from studies in neuronal systems, before turning to a review of recent work that aims to understand how this lncRNA contributes to cancer initiation, progression and metastasis, along with its possible clinical utility as a biomarker or therapeutic target.

Noise-induced time-dependent changes in oxidative stress in the mouse cochlea and attenuation by D-methionine

Oxidative stress in the cochlea is considered to play an important role in noise-induced hearing loss. This study determined changes in superoxide dismutase (SOD), catalase, lipid peroxidation (LPO) and the auditory brainstem response (ABR) in the cochlea of C57BL/6 mice prior to and immediately, 1, 3, 7, 10, 14 and 21 days after noise exposure (4 kHz octave band at the intensity of 110 dB SPL for 4 h). A significant increase in SOD activity immediately and on 1st day after noise exposure, without a concomitant increase in catalase activity suggested a difference in the time dependent changes in the scavenging enzymes, which facilitates the increase in LPO observed on day 7. The ABR indicated significant noise-induced functional deficits which stabilized in 2 weeks with a permanent threshold shift (PTS) of 15 dB at both 4 kHz and 8 kHz. The antioxidant D-methionine (D-Met) reversed the noise-induced changes in LPO levels and enzyme activities. It also significantly reduced the PTS observed on the 14th day from 15 dB to 5 dB for 4 kHz. In summary, the findings indicate that time-dependent alterations in scavenging enzymes facilitate the production of reactive oxygen species and that D-met effectively attenuates noise-induced oxidative stress and the associated functional loss in the mouse cochlea.

Serotonin turnover in different duration of sleep recovery in discrete regions of young rat brain after 24 h REM sleep deprivation

Sleep plays an important role in restorative function and serotonin (5-hydroxytryptamine: 5HT) equally plays important roles in sleep. Though various studies have revealed the roles of 5HT in sleep/wake cycle, the mechanism involved is yet unclear. In the present study we investigated alteration of the 5HT turnover in various regions of the young rat brains after 24 hours (h) REM sleep (sREM) deprivation to elucidate the roles of 5HT in sleep restoration function in the these regions. The 5HT turnover was evaluated by the ratio of 5-hydroxyindole acetic acid against 5HT. The sREM deprivation was performed by the inverted flowerpot technique. The 5HT turnover showed significant alteration in the all regions of the brain examined after 24h sREM deprivation, particular depending on the brain region. These results revealed that sREM modulates the 5HT turnover in the brain with region specificity and this may be one of the restorative functions of sleep indicating that sREM is regionally generated.

Serotonin turnover in discrete regions of young rat brain after 24 h REM sleep deprivation

The present study has attempted to elucidate the alteration of serotonin turnover after 24 h REM sleep deprivation in different regions in brain of young rat. Sleep deprivation was induced by the inverted flower pot technique. Results of this study show increased serotonin turnover after 24 h REM sleep deprivation in all the brain regions except in the hypothalamus. The decreased 5-HT ratio shows increased serotonin in the hypothalamus after 24 h sleep deprivation. This study indicates increased activity of serotonergic neurons in the hypothalamus after 24 h sleep deprivation. This also indicates that the hypothalamus plays a role in the immediate compensatory mechanism during 24 h REM sleep deprivation in young rats.

Periapical central giant cell granuloma misdiagnosed as odontogenic cyst

AIM

To present the clinicopathological features of a series of four periapically located central giant cell granulomas (CGCGs) that were misdiagnosed and treated as being of endodontic origin.

SUMMARY

Four cases of periapical CGCGs were submitted with a clinical diagnosis of either radicular or residual cyst. In two cases, root canal treatment had been performed previously. The patients were two women and two men whose age ranged from 31 to 85 years. Two cases were located in the mandibular premolar-molar region, and two in the anterolateral region of the maxilla. Two lesions were submitted for histological examination with a diagnosis of radicular cyst whereas the remaining two were submitted with a diagnosis of residual cyst.

KEY LEARNING POINTS

Periapical giant cell lesions may be unilocular and therefore misdiagnosed as an endodontic lesion because of their radiographic similarity to an inflammatory periradicular lesion, especially if the teeth have been root filled or if the vitality is negative or doubtful. It is important to follow up the healing process of a periapical radiolucency related to a root filled tooth and, in case of persistence, to perform surgery and to submit the specimen for histological examination.

Biogenic amine changes in brain regions and attenuating action of Ocimum sanctumin noise exposure

Broadband white noise exposure (100 dB) in wistar strain male albino rats significantly increased the levels of dopamine (DA), serotonin (5-HT) and 5-HT turnover in many of the discrete brain regions (cerebral cortex, cerebellum, hypothalamus, hippocampus, pons-medulla and corpus striatum) during sub-chronic noise exposure (4 h daily for 15 days). In acute (4 h for 1 day) and chronic noise exposures (4 h daily for 30 days) the levels were significantly altered only in certain regions. The turnover study of serotonin clearly indicates that neurotransmitter level alone cannot be an indicator, as in some brain regions the rate of synthesis matched with the degradation in order to maintain the normal levels. The intraperitoneal administration of 70% ethanolic extract of Ocimum sanctum(OS) at the dosage of 100 mg/kg body weight to animals subjected to noise exposure has prevented the noise induced increase in neurotransmitter levels without affecting the normal levels. This indicates that OS can be a probable herbal remedy for noise induced biogenic amine alterations.

Ostéonécrose des maxillaires chez des patients traités par bisphosphonates

INTRODUCTION

The latest generations of bisphosphonates constitute a major advance in the management of disorders including Paget's disease, osteoporosis, and osteolytic bone tumors. Recent reports describe numerous cases of osteonecrosis of the jaw in patients treated with bisphosphonates. Some of these reports mention predisposing factors, including surgical procedures, chemotherapy, and radiotherapy.

CASES

In the past 12 months, we have observed and treated 9 cases of maxillary osteonecrosis, which we present summarily.

DISCUSSION

Some of our cases (3 of 9), like many of those described in literature, do not present predisposing factors. The osteonecrosis may thus be due mainly to the effect of bisphosphonates that, by blocking bone remodeling, may cause excessive bone mineralization. If this hypothesis is confirmed, these cases of osteonecrosis may be due to excess doses. Better dose adjustment should thus help prevent this complication.

Effect of noise stress on free radical scavenging enzymes in brain

The levels of free radical scavenging enzymes in six discrete brain regions (cerebral cortex, cerebellum, midbrain, pons medulla, hippocampus and hypothalamus), after exposure to three different durations of noise stress (broadband white noise, 100dB, 4h/day, in acute: 1 day, sub acute: 15 days and chronic stress: 30 days) was studied in Wister strain male albino rats. Acute noise stress significantly increases the levels of superoxide dismutase (SOD: EC 1.15.1.1), catalase (EC 1.11.1.6), glutathione peroxidase (GPx: EC 1.11.1.9), oxidized glutathione (GSSG) and lipid peroxidation (LPO) and decreases the levels of reduced glutathione (GSH), GSH/GSSG ratio and protein thiols. The free radical scavenging enzymes levels, in sub acute and chronic noise stress also showed marked deviation in certain regions from the controls within the study duration. The results indicate that adaptation to noise stress does not occur immediately in all the brain regions. The noise induced alterations in free radicals may be assumed to serve as a linkage between the environmental noise and the manifestation of multifactorial diseases attributed to noise exposure. Moreover the quantification of the health effects of noise by the alterations in free radicals seems inappropriate in chronic noise stress.

Orofacial granulomas after injection of cosmetic fillers. Histopathologic and clinical study of 11 cases

BACKGROUND

Purposely, cosmetic injections in orofacial tissues of various resorbable, biodegradable, or permanent fillers may be followed by development of foreign-body granulomas. The aim of this article is to contribute to the histologic identification of the filler material.

METHODS

Histologic and clinical features of 11 cases of granulomas on orofacial fillers are described.

RESULTS

Only 3/11 patients knew the nature of the injected product. Four histologic patterns were found: (i) Artecoll, (ii) Dermalive, and (iii) New-Fill granuloma, all three of the classic giant cell granuloma type, differing in respect of foreign particles; and (iv) Liquid Silicone granuloma, which featured a cystic and macrophagic type. Information was often missing or misleading, patients or practitioners being reluctant to give the details.

CONCLUSION

Increasing demand for orofacial tissue augmentation makes pathologists face new, and sometimes, puzzling granuloma types. Identification of the foreign product might be required for therapeutic or medico-legal reasons.

Focal cemento-osseous dysplasia involving a mandibular lateral incisor

AIM

To report a case of focal cemento-osseous dysplasia (FCOD) affecting a single tooth misdiagnosed as an inflammatory periapical lesion.

SUMMARY

The patient, a black 47-year-old woman complained of pain affecting the right side of the mandible. Routine X-ray examination discovered a periapical radiolucency on the mandibular left lateral incisor (tooth 32), which was otherwise normal and not carious. As the response of this tooth to a vitality test was doubtful, the lesion was diagnosed as a periapical granuloma or cyst secondary to pulpal necrosis. Endodontic treatment and curettage of the periapical lesion were performed, and histological examination of the curettage material revealed a localized osseous dysplasia.

KEY LEARNING POINTS

FCOD may rarely affect only one tooth, resembling a periapical granuloma or cyst. Careful diagnosis is of paramount importance in cases of questionable periapical lesions affecting normal-looking teeth, before beginning treatment. FCOD generally requires no treatment. Biopsy is warranted in case of doubt.

[Solitary circumscribed neuroma (palisaded encapsulated neuroma) of the oral mucosa]

BACKGROUND

The solitary circumscribed neuroma or "Palisaded Encapsulated Neuroma" is an infrequent benign tumor of the skin of adults, often localised on the face, around the orifices. The involvement of the oral mucosa or of the vermilion border of the lips is rare.

CASE REPORTS

In our 5 cases, a small painless and more or less protruding nodule had been present for years on the mucosa of the hard palate (50 year-old man, 43 year-old woman), the soft palate (63 year-old woman), the vermilion border of the lower lip (48 year-old woman), and the gingiva (26 year-old man). The non specific clinical aspect did not permit a correct diagnosis.

DISCUSSION

Histologically, the solitary circumscribed neuroma is formed by a proliferation of Schwann cells arranged in interlacing bundles, featuring one or several well-limited nodules, sometimes surrounded by a thin capsule. At first sight, this aspect might sometimes mimic schwannoma or neurofibroma. The lesion is interspersed with a variable amount of axons. An association with neurofibromatosis or MEN syndrome type IIb has never been found. Even after incomplete excision the solitary circumscribed neuroma does not recur, a fact supporting a reactive rather than a neoplastic origin.

The importance of Na+/H+ exchanger for the generation of procoagulant activity by porcine blood platelets

This study addresses the role of the Na+/H+ exchanger (NHE) in the generation of procoagulant activity in blood platelets. It was found that monensin (simulating the action of NHE) and gramicidin (causing sodium influx without concomitant H+ efflux) produced a dose- and time-dependent increase in platelet procoagulant activity. Alkalinization of platelet cytosol by NH(4)Cl failed to evoke a procoagulant response. Collagen-induced procoagulant response was diminished in the absence of external Na+ and in the presence of EIPA (NHE inhibitor) or GF 109203X (protein kinase C inhibitor). Phorbol ester (PMA) produced a dose- and time-dependent generation of procoagulant response which was inhibited in the absence of the external Na+ and in the presence of EIPA. Platelets stimulated by collagen and PMA accumulated (22)Na+, a phenomenon inhibited in the presence of EIPA. The data indicate that development of procoagulant activity in platelets may occur as a result of Na+ influx via Na+/H+ exchanger.

Absence of leukocyte microchimerism in oral lichen planus (OLP): an in situ hybridisation study

Oral lichen planus (OLP) is a relatively common chronic inflammatory disease. The majority of patients are between 30 and 50 years of age with a higher incidence in females. The aetiology is unknown and various hypotheses on the pathogenic mechanisms, including autoimmunity, have been proposed over the years. In the present study, we investigated whether leukocyte microchimerism, a biological situation implicated in the aetiology of some autoimmune diseases, might play a role in the pathogenesis of OLP. We used in situ hybridisation to identify Y chromosome DNA in a series of formalin-fixed paraffin-embedded oral mucosa biopsies of women with established clinical and histological disease who had given birth to a male child. The positive control, two mucosal specimens from a man with OLP, showed over 90% of keratinocytes and cells within the inflammatory infiltrate, a positive nuclear signal. The negative control, biopsies from three women having carried only female foetuses and one nulliparous woman, all with OLP, did not show any nuclear signal. In the fifteen selected cases of OLP biopsies from women who had only male offspring, nucleated cells containing the Y chromosome were not detected within the chronic inflammatory infiltrate. These results suggest that unlike some other immunologically mediated diseases, leukocyte microchimerism does not seems to be involved in the pathogenesis of OLP.

Metastatic transitional cell carcinoma of the urinary bladder presenting as a mandibular gingival swelling

Oral cavity metastases mostly originate from the breasts, lungs, or kidneys. Transitional cell carcinoma (TCC), the most frequent malignant tumor of the urinary bladder, rarely metastasizes to the jaws. To the best of our knowledge, only 8 cases of bladder carcinoma have been reported in the English literature to metastasize to the jawbones. A new case of mandibular metastasis of urinary bladder TCC with extension to the gingiva is presented in a 64-year-old white man. The patient was referred for a periodontal infection of the upper right first molar. The clinical examination also showed a gingival swelling located in the lower left premolar region with a hypoasthesia of the left side of the lower lip. The gingival mass was biopsied, and the microscopy showed a mandibular metastatic TCC of the urinary bladder extending to the gingiva. Periodontists should be aware that, although gingival metastases are rare, when they occur they may mimic other local benign pathological conditions.

Transient T cell receptor beta-chain variable region-specific expansions of CD4+ and CD8+ T cells during the early phase of pediatric human immunodeficiency virus infection: characterization of expanded cell populations by T cell receptor phenotyping

T cell receptor (TCR) repertoire perturbations are commonly detected in CD8+ T cells during adult primary human immunodeficiency virus (HIV) infection and have been associated with HIV-specific cytotoxic T cell responses. By use of flow cytometry, transient high-level TCR beta-chain variable region-specific expansions of CD4+ and CD8+ T cells were observed more frequently in HIV-infected children than in children exposed to HIV who remained uninfected. TCR beta-chain diversity analysis and diversity-specific polymerase chain reaction were used to study the clonality of expanded CD4+ and CD8+ subsets. In CD8+ T cells, structural features of the complement-determining regions 3 were altered during the course of the expansion, and persistent TCR clonotypes were observed, consistent with antigen-driven selection. In contrast, TCR beta-chain variable region-specific expansions without clonotypic overrepresentation or persistence were observed in CD4+ T cells, possibly related to HIV-specific helper T cell responses or to the progressive destruction of the CD4+ cell compartment.

Epithelial odontogenic ghost cell tumour of the mandibular gingiva

The epithelial odontogenic ghost cell tumour (EOGCT) is considered as a solid 'neoplastic' variant of the calcifying odontogenic cyst and is an uncommon lesion for which various names have been proposed over the years. We describe here an extraosseous case occurring on the edentulous mandibular gingiva in the right bicuspid area of a 70-year-old woman. The lesion was a painless nodule that appeared clinically as a hyperplastic mass, which was considered to be of reactive nature. Radiographic examination showed a localised resorption of the underlying mandibular bone. The tumour was excised; there was no recurrence at a 2-year follow-up examination.

Intravascular papillary endothelial hyperplasia of the mouth: report of six cases and literature review

OBJECTIVE

Oral intravascular papillary endothelial hyperplasia (IPEH) is an uncommon, reactive vascular lesion with no specific clinical features. Microscopically two subtypes have been described: a pure and a mixed form. The importance of IPEH is in its resemblance to angiosarcoma. The aim of this study was to evaluate both the prevalence of IPEH in a consecutive series of oral vascular malformations and the clinico-pathological features.

MATERIALS AND METHODS

Histological sections of 103 consecutive cases filed as vascular malformations were reviewed for histopathological criteria of IPEH.

RESULTS AND CONCLUSION

We found six cases of oral IPEH, of which three were diagnosed previously. Five of these cases were in males, and the mean age was 58 years. It was usually described as a blue or reddish nodule. The lower lip mucosa was the most common site followed by the tongue and the upper lip. Histologically, thrombi were always present and five out of the six lesions appeared in a mixed form, while only one was in a pure form. Three cases were diagnosed at an early stage and in the other three, the lesions were well-established. In this series, IPEH associated with vascular malformation was more common than reported in previous studies. Lesions at early stages, especially in the mixed form, may be unnoticed.

Prevalence of risk factors associated with human papillomavirus infection in women living with HIV. Canadian Women's HIV Study Group

BACKGROUND

Concurrent infection with HIV and human papillomavirus (HPV) in women is associated with increased rates of cervical dysplasia and shorter survival following the development of cervical cancer. The authors examined risk factors for HPV infection at study entry in HIV-positive women enrolled in the Canadian Women's HIV Study, a prospective open cohort study.

METHODS

Subjects eligible for this analysis included the 375 HIV-positive women in the Canadian Women's HIV Study for whom HPV test results were available. Questionnaires on behavioural and clinical information, Pap smears, cervicovaginal lavage specimens and vaginal tampon specimens for HPV detection and typing by polymerase chain reaction were obtained at study entry.

RESULTS

Overall, 67.2% (252/375) of the women were HPV-positive; the global prevalence of intermediate- and high-risk oncogenic HPV types was 49.1% (184/375). Women with squamous cell dysplasia (32/294) were more likely to have HPV infection than those without dysplasia (90.6% v. 62.6%; p = 0.002). Multivariate logistic regression analysis, with adjustment for number of lifetime partners and history of STD, revealed that the following risk factors were independently associated with HPV infection: CD4 count of less than 0.20 x 10(9)/L (adjusted odds ratio [OR] 1.99 [95% confidence interval (Cl) 1.17-3.37 (p = 0.011)]), non-white race (adjusted OR 2.00 [95% Cl 1.17-3.42 (p = 0.011)]), inconsistent condom use in the 6 months before study entry (adjusted OR 2.02 [95% Cl 1.16-3.50 (p = 0.013)]), and lower age, with women age 30-39 years (adjusted OR 0.51 [95% Cl 0.30-0.87 (p = 0.013)]) and age 40 years or older (adjusted OR 0.52 [95% Cl 0.26-1.01 (p = 0.052)]) compared with women less than 30 years of age.

INTERPRETATION

Close monitoring for HPV-related effects is warranted in all HIV-positive women, particularly younger, non-white women who do not always use condoms. Counselling for women living with HIV, particularly younger women, should emphasize the importance of regular cytological screening, with increasing frequency as the CD4 count falls.

Natural history of Epstein-Barr virus infection in a prospective pediatric cohort born to human immunodeficiency virus-infected mothers

To determine whether Epstein-Barr virus (EBV) constitutes a contributing factor in AIDS and, conversely, whether the human immunodeficiency virus (HIV) alters the course of primary EBV infection in a pediatric population, 62 children born to HIV-infected mothers and prospectively followed were evaluated. EBV infection was documented by EBV-specific serology and polymerase chain reaction and by clinical history. HIV infection status was determined according to the Centers for Disease Control and Prevention pediatric classification system. Demographics from HIV-infected and HIV-uninfected children were comparable. The data suggest that HIV-infected children may acquire primary EBV infection earlier in life. The incidence of accompanying splenomegaly or hepatomegaly (or both) around the time of EBV seroconversion was higher among HIV-infected children than among HIV-uninfected children. In contrast, HIV disease progression and HIV-1 RNA load did not seem to be influenced by primary EBV infection.

Antiribonucleoprotein antibodies in children with HIV infection: a comparative study with childhood-onset systemic lupus erythematosus

A number of clinical and laboratory features of HIV infection are found in systemic lupus erythematosus (SLE). The objective of this study was to analyze the presence of circulating antibodies to small nuclear ribonucleoproteins (snRNP) in both diseases. Sera from 44 HIV-infected children, from 22 patients with childhood-onset SLE, and from 50 healthy children were studied. Anti-snRNP antibodies were detected by ELISA using recombinant and affinity-purified nuclear antigens, by counterimmunoelectrophoresis (CIE), and by immunoblotting using extractable nuclear antigens. Results included the detection of anti-snRNP antibodies by ELISA in 30 HIV-infected patients (68.1%) and 19 SLE patients (86.3%). These antibodies were directed against U1-RNP (61.3% and 77.2%, respectively), Sm (29.5% and 54.5%, respectively), 60 kDa Ro/SS-A (47.7% and 50%, respectively), and La/SS-B proteins (18.1% and 9%, respectively). None of the HIV-infected children and 11 SLE patients (50%) showed anti-snRNP antibodies by CIE. None of the HIV-infected patients showed anti-70 kDa U1-RNP or anti-D-Sm antibodies by immunoblotting. No differences between the two groups were noted on the presence of nonprecipitating anti-snRNP antibodies. No such reactivities were observed among the normal sera tested. The authors concluded that nonprecipitating anti-snRNP antibodies in HIV-infected children are as frequent as in childhood-onset SLE. The significance of these antibodies is not clear at present. Although polyreactive and low-affinity antibodies and a mechanism of molecular mimicry may explain these results, a specific stimulation of B cells by nuclear antigens could not be excluded.

Prevalent diseases of ostrich chicks farmed in Canada

In Canada, ostriches are now slaughtered for their meat and hides. The mortality rate in ostrich farming is highest in chick units. An increased chick survival rate impacts positively on production and profit. This paper will focus on common health disorders that affect chick production costs. These are discussed under the following categories: digestive, orthopedic, respiratory, and integumentary disorders. Methods for elimination or reduction of these mortality factors are also discussed.

Recurrent peripheral giant cell granuloma associated with cervical resorption

A case of recurrent peripheral giant cell granuloma in a 38-year-old man is reported. The lesion was localized on the attached gingiva of the lower left second premolar (tooth #35). The surgical excision of the lesion revealed a superficial resorption of the cervical region of the involved tooth. The resorption was smoothed out, and there was no sign of recurrence or further resorption after 14 months. Root resorption, although extremely rare, may be associated with peripheral giant cell granuloma.

The association of lifetime psychiatric illness and increased retinopathy in patients with type I diabetes mellitus

Forty-nine patients with Type I diabetes mellitus were assessed to examine the relationship between lifetime prevalence of psychiatric illness and retinopathy severity. The subjects with a history of psychiatric illness had significantly worse retinopathy than the subjects without psychiatric illness. Eighty-nine percent of the subjects with severe nonproliferative retinopathy or proliferative retinopathy had a history of psychiatric illness, predominantly affective illness. In addition, the subjects with a history of psychiatric illness had significantly higher current glycohemoglobin levels than those with no psychiatric history. This study's findings suggest that psychiatric illness may be a risk factor for development of retinopathy in Type I diabetic patients.

Antibody responses to two Epstein-Barr virus (EBV) nuclear antigens (EBNA-1 and EBNA-2) during EBV primary infection in children born to mothers infected with human immunodeficiency virus

A variety of antibody response patterns to the latent Epstein-Barr nuclear antigen (EBNA) family have been described in different groups of subjects infected with Epstein-Barr virus (EBV). The purpose of this study was to characterize the immune response to two EBNA proteins, EBNA-1 and EBNA-2, in a population of children who were born to mothers infected with HIV and who underwent EBV seroconversion. Serial serum specimens from 33 children (nine were infected with HIV, and 24 were not infected) were evaluated for the presence of antibodies to EBNA-1 and EBNA-2 by anticomplement immunofluorescence. All the EBNA serology profiles observed for children in our study who were not infected with HIV were consistent with those described for immunocompetent hosts with acute EBV infection, i.e., development of antibodies to EBNA-1, often preceded by the appearance of a humoral immune response to EBNA-2. In contrast, following EBV primary infection in HIV-infected children, antibodies to EBNA-2 arose after antibodies to EBNA-1 and tended to persist. Further studies are needed to investigate the role of EBNA-2 serology as a prognostic marker in HIV-infected children.

Pleomorphic adenoma of the palate in a child: 9-year follow-up

Pleomorphic adenoma (PA), the most common of the benign salivary gland tumors, is an extremely rare entity in children before the age of 14 years. Until now, only five cases arising in the palate have been reported in detail. A case of PA of the hard palate in a 10-year-old girl is presented. After a 9-year follow-up period, no recurrence was observed.

Behavioral problems of farmed ostriches in Canada

Ostriches farmed in Canada often have particular behavioral problems that are brought about by periods of extreme confinement during winter months. Although they still perform normal species specific behaviors such as twirling, kanteling, and kicking, abnormal behaviors become prominent when excessively confined. They include for all age groups of ostriches, feather-picking, behavioral stargazing, dietary indiscretion, pica, anorexia and adipsia, and aggression. These abnormal behaviors initiated by inadequate husbandry techniques, eventually become medical problems because of their severity.