Epstein–Barr virus-related dacryocystitis: a case report

Background and objective

Acute dacryocystitis is an atypical and rare manifestation of pediatric mononucleosis still widely underdiagnosed in clinical practice. We report this rare condition and describe challenges in its diagnosis and treatment on the basis of a presented case.

Case presentation

A 6-year-old Caucasian girl without any ophthalmic history was admitted for right preseptal cellulitis requiring intravenous antibiotic therapy. During hospitalization, she developed a fluctuating lump in the nasolacrimal region which resembled an abscess, both clinically and radiologically. There was no spontaneous purulent discharge. Serology was positive for acute mononucleosis and Epstein–Barr virus-related dacryocystitis was diagnosed. Following multidisciplinary discussion, she was treated conservatively with digital lacrimal sac massages and intravenous antibiotic therapy with an excellent outcome.

Discussion

This rare form of Epstein–Barr virus is poorly documented in the literature, and thus barely known. As initial symptoms are nonspecific (rhinitis, fever, eyelid edema and erythema lack of purulent discharge, and moderate bilateral cervical lymphadenopathy), diagnosis is often difficult. Nevertheless, differentiating between dacryocystitis and abscess is crucial to select the appropriate treatment and avoid unnecessary, potentially harmful surgery. Conservative management of dacryocystitis appears to be the gold standard of treatment.

Conclusion

Acute dacryocystitis in children free of ophthalmic history should raise suspicion of primary Epstein–Barr virus infection. With conservative treatment, prognosis appears to be excellent; therefore, surgery should be avoided as much as possible.

Presentation of trypanosomiasis in nkhotakota

In 2002, we identified 28 people in Nkhotakota District who were suffering from Human African Trypanosomiasis (HAT). Sixteen of these were identified when they presented to the District Hospital with a febrile illness. The remaining twelve were identified through a rural cross-sectional survey, in which 500 people were visited in their homes, persons found to be febrile, were examined by blood film microscopy. Of the 28 people, 50% (14) presented within a month of the onset of symptoms. Sixteen (57%) had splenomegaly, and 24 were anaemic ([Hb] <12 g/dl). Four patients died (14%), of which two were in the late stage of the disease. None of the patients recall having a chancre that could be attributed to the bite of tsetse flies. 9 out of 28 (32%) reported illness longer than 90 days. Of the 9 patients 6 (66%) of them remained in the early stage after reporting illness of 180 days. This study reports on the prevalence and clinical features of Trypansoma brucei rhodesiense infection in a endemic district in Malawi.

Regulation of vesicular monoamine and glutamate transporters by vesicle-associated trimeric G proteins: new jobs for long-known signal transduction molecules

Neurotransmitters of neurons and neuroendocrine cells are concentrated first in the cytosol and then in either small synaptic vesicles ofpresynaptic terminals or in secretory vesicles by the activity of specific transporters of the plasma and the vesicular membrane, respectively. In the central nervous system the postsynaptic response depends--amongst other parameters-on the amount of neurotransmitter stored in a given vesicle. Neurotransmitter packets (quanta) vary over a wide range which may be also due to a regulation of vesicular neurotransmitter filling. Vesicular filling is regulated by the availability of transmitter molecules in the cytoplasm, the amount of transporter molecules and an electrochemical proton-mediated gradient over the vesicular membrane. In addition, it is modulated by vesicle-associated heterotrimeric G proteins, Galphao2 and Galphaq. Galphao2 and Galphaq regulate vesicular monoamine transporter (VMAT) activities in brain and platelets, respectively. Galphao2 also regulates vesicular glutamate transporter (VGLUT) activity by changing its chloride dependence. It appears that the vesicular content activates the G protein, suggesting a signal transduction from the luminal site which might be mediated by a vesicular G protein-coupled receptor or as an alternative possibility by the transporter itself. Thus, G proteins control transmitter storage and thereby probablylink the regulation of the vesicular content to intracellular signal cascades.

Properties of pseudopotentials for higher partial waves

Contact psuedopotentials for relative angular momentum greater than zero are of interest for the study of cold atomic gases. For bosons, it is known that when the s-wave scattering length becomes infinite, an infinite number of three-body bound states, called Efimov states, are predicted by such potentials. Realistic potentials also exhibit the such states, thus a study of the Efimov effect for contact psuedopotentials for higher partial waves and fermions is important for the study of cold atoms. In this Letter we analyze three-body states of three particles interacting via psuedopotentials for higher partial waves and show that there is an Efimov effect for three fermions interacting via p-wave psuedopotentials.

Hypocaloric total parenteral nutrition: effectiveness in prevention of hyperglycemia and infectious complications--a randomized clinical trial

OBJECTIVE

To determine whether the frequency rate of hyperglycemia and infectious complications can be reduced by an underfeeding strategy in patients requiring total parenteral nutrition (TPN), without deleterious effects on nitrogen balance.

DESIGN

Prospective, randomized, controlled nonblinded trial.

SETTING

A university-affiliated teaching hospital with a dedicated TPN service.

PATIENTS

TPN was initiated in 40 adult patients and continued for > or =5 days.

INTERVENTION

Two different TPN feeding strategies were compared: hypocaloric feeding (1 L containing 70 g protein and 1000 kcal) and standard weight-based regimen, begun in similar amounts initially, but advanced in increments toward 25 kcal and 1.5 g protein/kg dry (or adjusted ideal) weight.

MEASUREMENTS AND MAIN RESULTS

We evaluated the frequency rate of hyperglycemia, average blood glucose, numbers and types of infections while receiving nutritional support and nitrogen balance after 5 days of TPN. There were significant differences between the quantities of calories, dextrose, fat, and protein provided to the two groups. However, average blood glucose, frequency rate of hyperglycemia, and infection rates (from intravenous catheter, pneumonia, and wound/abdominal collection) were similar in each group. The control group showed a trend toward a higher insulin requirement. Nitrogen balance, only available as a subset, was significantly more negative in the hypocaloric group.

CONCLUSIONS

Provision of TPN to a goal of 25 kcal/kg was not associated with more hyperglycemia or infections than a deliberate underfeeding strategy. A regimen of 1.5 g/kg protein in conjunction with 25 kcal/kg did, however, provide significant nutritional benefit in terms of nitrogen balance in comparison with hypocaloric TPN.

T-Cell responses during Trypanosoma brucei infections in mice deficient in inducible nitric oxide synthase

We have investigated the possibility that nitric oxide (NO) synthesis may affect the course of a trypanosome infection via T-cell responses using mice deficient in inducible NO synthase (iNOS). Parasitemia levels increased at the same rate in both iNOS-deficient homozygous and control heterozygous mice, and peak parasitemia values were the same in both groups. However, the heterozygous mice maintained higher parasitemia levels after the peak of an infection than the homozygous mice due to a decrease in the rate of clearance of parasites. In iNOS-deficient mice there was an increase in the numbers of total CD4(+) cells and activated (interleukin-2 receptor-expressing) CD4(+) cells in infected mice compared with the numbers in uninfected mice. Spleen cells from infected iNOS-deficient mice displayed increased proliferative responses and gamma interferon secretion when stimulated in vitro than those of control mice. These data suggest that NO production depresses T-helper 1-like responses generated during Trypanosoma brucei infections, thus promoting the survival of the parasite.

Bone marrow nitric oxide production and development of anemia in Trypanosoma brucei-infected mice

Mice infected with Trypanosoma brucei rapidly develop anemia, with the number of circulating erythrocytes reduced by 50% within a week after infection. The present study investigated the relationship between anemia and bone marrow nitric oxide (NO) production. Bone marrow cell populations from T. brucei-infected mice exhibited elevated levels of NO synthase activity which was inhibitable by NG-nitro-L-arginine methyl ester. NO production was found to coincide with suppressed bone marrow T-cell proliferation in response to stimulation with the mitogen concanavalin A both in vitro and in vivo. As this indicated that NO may inhibit proliferation in other cell types, particularly hemopoietic precursors, we examined the role of NO in anemia during trypanosome infection. NO production correlated directly with the development of anemia, and treatment of infected mice with NG-nitro-L-arginine methyl ester in vivo to systemically inhibit NO synthesis led to a significant reduction in the anemia. Thus, elevated NO production in the bone marrow of T. brucei-infected mice is likely to play a significant role in the anemia resulting from T. brucei infection.

Inhibition of nitric oxide synthesis leads to reduced parasitemia in murine Trypanosoma brucei infection

In murine Trypanosoma brucei infection, macrophage activation and nitric oxide (NO) production lead to suppressed splenic T-cell responses (J. Sternberg and F. McGuigan, Eur. J. Immunol. 22:2741-2744, 1992). In this study, evidence is presented that NO has no detectable trypanocidal activity under simulated in vivo conditions and that inhibition of NO production in vivo results in reduced parasitemia.

Semiconductor laser-induced fluorescence detection in capillary electrophoresis using a cyanine dye

Cy5, an activated carboxyl cyanine fluorophore, was characterized by capillary electrophoresis (CE) using a semiconductor laser at 652 nm to induce fluorescence. Hydrolysis of the activated Cy5 in the presence of ammonia results in the formation of a mono- and diamide and a dicarboxylic acid. A Cy5-labeled oligonucleotide M13 primer for DNA sequencing (M13mp18 template) was synthesized with a purity of better than 95%. The labeled primer was analyzed by liquid chromatography, using UV-visible detection, and by CE, monitored by laser-induced fluorescence (LIF) detection. Analysis of the Cy5-labeled oligonucleotide primer by CE-LIF in a 9% polyacrylamide gel-filled capillary indicated the purity of the major Cy5-oligonucleotide primer was greater than 90%. The detection sensitivity for Cy5-based CE-LIF detection system with a 2.5-mW red semiconductor laser is about 10(-10) M.

Nitric oxide mediates suppression of T cell responses in murine Trypanosoma brucei infection

African trypanosomes induce a generalized state of immunosuppression in their mammalian hosts. One characteristic of this is a suppression of lymphocyte responses to mitogen, which is mediated by suppressor macrophages. We investigated the involvement of nitric oxide in this phenomenon. Both peritoneal and splenic cell cultures from infected mice released nitrite and this was inhibitable by NG-monomethyl L-arginine (L-NMMA). The release of nitrite correlated with suppressed splenic T cell proliferative responses to concanavalin A. It was shown that adherent spleen cells from infected mice mediate suppression, which could be abrogated by L-NMMA. These results suggest that in T. brucei infection, the activation of macrophages to produce nitric oxide leads to impaired lymphocyte responses and immunosuppression.

Genetic exchange in African trypanosomes

African trypanosomes are important pathogens of humans and domestic animals, but little was known, until recently, of the genetic system of these parasites. Recent results demonstrate the existence of nonobligatory genetic exchange between different stocks of T. brucei. A number of models have been put forward for the mechanism of genetic exchange, including a fusion model with subsequent random loss of chromosomes and a more conventional mendelian system.

Gene exchange in African trypanosomes: frequency and allelic segregation

The existence of a system of genetic exchange in Trypanosoma brucei is now established, but the frequency with which mating occurs and the mechanisms by which genes are exchanged are still unknown. This paper presents the results of a study of one pair of trypanosome stocks, which show that mating is a non-obligatory but frequent event in a life-cycle stage within the insect vector. Analysis of ten progeny clones using a total of eleven markers (iso-enzymes and DNA probes detecting restriction fragment length polymorphisms) has indicated that segregation of alleles occurs at five of these loci. The segregation patterns of a polymorphic EcoRI site in the maxi-circle of the kinetoplast DNA (kDNA) show that the progeny inherit one or other of the parental kDNA types. These results demonstrate that segregation of alleles occurs and that new combinations of alleles at different loci are generated in the progeny clones. The implications of these findings for defining the mechanism of gene exchange are discussed in relation to a simple mendelian genetic system involving meiosis and syngamy.

Neuropeptide expression in cultures of adult sensory neurons: modulation of substance P and calcitonin gene-related peptide levels by nerve growth factor

In contrast to developing sensory neurons, the survival of adult rat dorsal root ganglion neurons in pure neuronal culture is not dependent on specific neurotrophic factors such as nerve growth factor or brain-derived neurotrophic factor [Lindsay R. M. (1988) J. Neurosci. 8, 2394-2405]. In the present study we have examined possible modulatory effects of nerve growth factor on the neuropeptide content of sub-populations of adult rat dorsal root ganglion neurons in vitro. During the first 1-2 days in culture the neuropeptides substance P and calcitonin gene-related peptide could be detected by immunofluorescence staining in cultures grown in the presence or absence of nerve growth factor, but at longer times in nerve growth factor-deprived cultures there was loss of immunoreactive staining for both peptides. In the presence of nerve growth factor, however, the percentage of substance P- and calcitonin gene-related peptide-immunoreactive neurons remained relatively constant, for at least 14 days, at levels that were similar to the percentage of such peptide-containing neurons found in sections of adult rat dorsal root ganglia. Quantitation by radioimmunoassay of the levels of substance P and calcitonin gene-related peptide in cultures grown in the presence or absence of nerve growth factor agreed with the qualitative observations obtained by immunofluorescence: 10-15-fold higher levels of substance P and calcitonin gene-related peptide were found in cultures grown with nerve growth factor for 18 days, as compared to nerve growth factor-deprived cultures. In nerve growth factor-treated cultures increased levels of substance P and calcitonin gene-related peptide were observed within 3-6 days in vitro, and further steady increases in the levels of both peptides were found up to 18 days. A low basal level of both peptides could always be detected, even in the presence of an excess of antibodies to nerve growth factor. Up-regulation of the synthesis of substance P and calcitonin gene-related peptide did not depend on nerve growth factor being present at the initiation of the cultures, as elevated levels of both peptides could be induced in cultures even after up to 10 days' prior deprivation of nerve growth factor. Removal of nerve growth factor from the cultures resulted in reduced levels of peptide within 3 days.(ABSTRACT TRUNCATED AT 400 WORDS)

Nerve growth factor (NGF) regulates adult rat cultured dorsal root ganglion neuron responses to the excitotoxin capsaicin

An overlap between subpopulations of nerve growth factor (NGF)-responsive and capsaicin-sensitive dorsal root ganglion (DRG) sensory neurons has been suggested from a number of in vivo studies. To examine this apparent link in more detail, we compared the effects of capsaicin on adult rat DRG neurons cultured in the presence or absence of NGF. Capsaicin sensitivity was assessed histochemically by a cobalt staining method, by measuring capsaicin-induced 45Ca2+ uptake, and by electrophysiological recording of capsaicin-evoked membrane currents. When cultured with NGF, approximately 50% of these adult DRG neurons were capsaicin-sensitive, whereas adult sympathetic neurons or ganglionic nonneuronal cells were insensitive. DRG cultures grown in the absence of NGF, however, were essentially unresponsive to capsaicin. Capsaicin sensitivity could be regained fully within 4-6 days of replacement of NGF. These results indicate that, at least in vitro, NGF can modify the capsaicin sensitivity of adult DRG neurons.

Nuclear DNA content of Trypanosoma congolense

We have measured the nuclear DNA content of the major life cycle stages of Trypanosoma congolense, in two clones of geographically distant origin. We find that nuclear DNA content in epimastigote, mammalian blood-stream and metacyclic forms is constant and that the nuclear DNA contents of the two clones were 0.1 pg and 0.09 pg, respectively.

Gene exchange in African trypanosomes: characterisation of a new hybrid genotype

We describe the isolation of a hybrid Trypanosoma brucei clone following the mixed cyclical transmission of two parental clones through tsetse flies. The characterisation of this clone reveals some new facets of the process of genetic exchange in T. brucei. The inheritance of four isoenzyme loci and restriction fragment polymorphisms at two loci was interpretable in 'mendelian' genetic terms, involving meiosis either before or after the genetic exchange event. However, at a further two isoenzyme loci a deviation from mendelian behaviour was observed. Pulse field gel analysis showed that the hybrid clone possessed a new combination of intermediate size chromosomes. Examination of kinetoplast DNA variants showed uniparental kinetoplast inheritance, and with reference to previous work we conclude that the kinetoplast can be inherited from either parent. The nuclear DNA content of the hybrid clone was measured and found to be identical to the parental nuclear DNA contents. This finding, together with the inheritance of isoenzyme and RFLP markers, is discussed with respect to possible models for genetic exchange.

The relationship between emerging neural crest cells and basement membranes in the trunk of the mouse embryo: a TEM and immunocytochemical study

The earliest stage of neural crest cell (NCC) migration is characterized by an epitheliomesenchymal transformation, as the cells leave the neural tube. There is evidence that in a number of cell systems this transformation is accompanied by alteration or depletion of associated basement membranes. This study examines the ultrastructural relationship between mouse NCCs and adjacent basement membranes during the earliest stages of migration from the neural tube. Basement membranes were identified by transmission electron microscopy (TEM) and immunofluorescence using antibodies to type-IV collagen. The ultrastructural features of NCCs and their relationship with surrounding tissues were also examined using TEM. In the dorsal region of the neural tube, from which NCCs originate, the basement membrane was depleted or absent, and with the immunofluorescence technique it was shown that this pattern was reflected in a deficit of type-IV collagen. TEM observations indicated that ultrastructurally NCCs differ from their neuroepithelial neighbours only in overall cell shape and their relationship to other cells and the extracellular matrix.

The relationship between emerging neural crest cells and basement membranes in the trunk of the mouse embryo: a TEM and immunocytochemical study

The earliest stage of neural crest cell (NCC) migration is characterized by an epitheliomesenchymal transformation, as the cells leave the neural tube. There is evidence that in a number of cell systems this transformation is accompanied by alteration or depletion of associated basement membranes. This study examines the ultrastructural relationship between mouse NCCs and adjacent basement membranes during the earliest stages of migration from the neural tube. Basement membranes were identified by transmission electron microscopy (TEM) and immunofluorescence using antibodies to type-IV collagen. The ultrastructural features of NCCs and their relationship with surrounding tissues were also examined using TEM. In the dorsal region of the neural tube, from which NCCs originate, the basement membrane was depleted or absent, and with the immunofluorescence technique it was shown that this pattern was reflected in a deficit of type-IV collagen. TEM observations indicated that ultrastructurally NCCs differ from their neuroepithelial neighbours only in overall cell shape and their relationship to other cells and the extracellular matrix.

Distribution of fibronectin, laminin and entactin in the environment of migrating neural crest cells in early mouse embryos

The distribution of the extracellular matrix molecules fibronectin, laminin and entactin was studied in frozen sections of 9 1/2-day mouse embryos in order to relate their presence to neural crest cell migration. It was found that all three components were present in basement membranes, laminin and entactin being mainly restricted to these. Fibronectin was present at high levels in basement membranes and extracellular spaces throughout the embryo, including the regions of neural crest cell migration. Fibronectin is known to affect migration in a variety of cell systems, so its presence in the embryo at the time of migration may indicate that it is influencing cell movement. This influence is likely to be via the cell surface through interactions with other matrix components such as glycosaminoglycans, and possibly entactin and laminin.

Distribution of fibronectin, laminin and entactin in the environment of migrating neural crest cells in early mouse embryos

The distribution of the extracellular matrix molecules fibronectin, laminin and entactin was studied in frozen sections of 9½-day mouse embryos in order to relate their presence to neural crest cell migration. It was found that all three components were present in basement membranes, laminin and entactin being mainly restricted to these. Fibronectin was present at high levels in basement membranes and extracellular spaces throughout the embryo, including the regions of neural crest cell migration. Fibronectin is known to affect migration in a variety of cell systems, so its presence in the embryo at the time of migration may indicate that it is influencing cell movement. This influence is likely to be via the cell surface through interactions with other matrix components such as glycosaminoglycans, and possibly entactin and laminin.

Dot-blotting--a novel screening assay for antibodies in hybridoma cultures

A novel solid phase radioimmunoassay using nitrocellulose filters, is described. The method is of particular value in screening hybridoma cultures for monoclonal antibodies against chromosomal protein. Also it permits detection of antibodies directed against epitopes stable to SDS denaturation.

Effect of vitamin E on post irradiation death in mice

The 30-day survival after exposure to 800 Rad 60Co gamma radiation has been compared for female mice maintained on vitamin E deficient, vitamin E supplemented or regular lab rations before and/or after irradiation. Pre- or post-irradiation dietary supplementation had no effect on survival; however, injection of alpha-tocopherol immediately after irradiation significantly reduced radiation lethality.

Bilateral renal cell carcinoma

Bilateral renal cell carcinoma was diagnosed simultaneously in 6 patients and sequentially in 4 patients, 3 to 14 years after the first tumor had been removed by nephrectomy. Four patients treated conservatively with incomplete excision of the malignant disease are alive 18 months to 14 years after diagnosis. Oue experience suggests that a radical excision, requiring renal dialysis or transplantation, is seldom warranted.

Radiation and pregnancy

Irradiation during pregnancy may occur either as the result of radioactive pollution of the environment, or during a medical procedure using x-rays or radionuclides. While the former is usually unforeseeable, the latter is known and accepted by both physician and patient.Recent statistics estimate that about one quarter of pregnant women have had a radiographic experience during the pregnancy, either for obstetrical reasons or in the course of medical and dental examinations. The amount of radiation delivered to the fetus is in the range of one rad or less. Radionuclidic procedures may result in fetal radiocontamination, chiefly after placental transfer and fetal uptake. Radioiodine, radioactive calcium and selenomethionine are dangerous for the fetus, since they cross the placenta freely and are taken up by fetal tissues. The labelled proteins, radiocolloids and some mercury compounds remain in the maternal compartment and therefore can affect the fetus only through their gamma radiation at some distance from the fetus.The teratogenic effect, the leukemogenic threshold and the lowered resistance to neonatal infections have been demonstrated after irradiation with doses far higher than those encountered during diagnostic applications of ionizing radiation. Statistical data suggest an increase of susceptibility to leukemia in infancy after intra-uterine irradiation at a diagnostic level. Cytogenic analysis may.... offer valuable data for the establishment of the extent of radiation damage.