Viral hemorrhagic fever]

Rett syndrome and Angelman syndrome are neurodevelopmental disorders characterized by severe intellectual disability, microcephaly, speech disturbance, movement disorders with gait and/or truncal ataxia, and occasionally a similar facial appearance. Both conditions can be difficult to diagnose in girls early in their clinical course and can be difficult to distinguish from each other. Genomic imprinting is a known association in Angelman syndrome and previously has been suggested in Rett syndrome. Our aim was to evaluate the methylation status in a cohort of classical patients with Rett syndrome, using a methylation system for chromosome 15q11-13. Methylation analysis of chromosome 15 has not been previously reported in Rett syndrome. Furthermore, we document the clinical features of 31 girls with classical Rett syndrome and confirm the phenotypic similarities between Rett syndrome and Angelman syndrome. The methylation studies in these girls with Rett syndrome were normal. This excludes an imprinting error of the Angelman syndrome critical region on chromosome 15 (15q11-13) as an association with Rett syndrome, and indicates that methylation studies may be useful in distinguishing Rett syndrome from Angelman syndrome in young patients with an overlapping clinical phenotype. A normal methylation pattern, however, does not exclude the diagnosis of Angelman syndrome and clear distinction between the two syndromes will evolve over time.     

Dengue and dengue hemorrhagic fever

In this report, the genomic DNA was examined from two siblings with gonadal LH resistance. A 46,XY pseudohermaphrodite presented with female external genitalia and his 46,XX sister exhibited menstrual irregularities (oligoamenorrhea) and infertility. Exons 1-11 of the LH receptor (LHR) gene were amplified by the PCR using different sets of intronic primers and were directly sequenced. Sequencing revealed that both individuals carried a deletion of nucleotides 1822-1827, resulting in the deletion of Leu-608 and Val-609 within the seventh transmembrane helix. This mutation was introduced into a recombinant human (h) LHR cDNA. Transfections of 293 cells with hLHR(wt) vs. hLHR(deltaL608,V609) revealed that very little of the mutant receptor was expressed at the cell surface. This was due to both a decrease in the total amount of receptor expressed as well as to an increased intracellular retention of the mutant receptor. In spite of the decreased cell surface expression of the mutant, sufficient amounts were present to allow for assessment of its functions. Equilibrium binding assays showed that the cell surface hLHR(deltaL608,V609) binds hCG with an affinity comparable to that of the wild-type receptor. However, the cells expressing the hLHR(deltaL608,V609) exhibit only a 1.5- to 2.4-fold stimulation of cAMP production in response to hCG. In contrast, cells expressing comparably low levels of hLHR(wt) responded to hCG with 11- to 30-fold increases of cAMP levels. Therefore, the testicular and ovarian unresponsiveness to LH in these patients appears to be due to a mutation of the hLHR gene in which Leu-608 and Val-609 are deleted. As a consequence, the majority of the mutant receptor is retained intracellularly. The small percentage of mutant receptor that is expressed at the cell surface binds hormone normally but is unable to activate Gs.     

Replication of Marburg virus in human endothelial cells. A possible mechanism for the development of viral hemorrhagic disease

Marburg and Ebola virus, members of the family Filoviridae, cause a severe hemorrhagic disease in humans and primates. The disease is characterized as a pantropic virus infection often resulting in a fulminating shock associated with hemorrhage, and death. All known histological and pathophysiological parameters of the disease are not sufficient to explain the devastating symptoms. Previous studies suggested a nonspecific destruction of the endothelium as a possible mechanism. Concerning the important regulatory functions of the endothelium (blood pressure, anti-thrombogenicity, homeostasis), we examined Marburg virus replication in primary cultures of human endothelial cells and organ cultures of human umbilical cord veins. We show here that Marburg virus replicates in endothelial cells almost as well as in monkey kidney cells commonly used for virus propagation. Our data support the concept that the destruction of endothelial cells resulting from Marburg virus replication is a possible mechanism responsible for the hemorrhagic disease and the shock syndrome typical of this infection.     

Identification of alpha-dystroglycan as a receptor for lymphocytic choriomeningitis virus and Lassa fever virus

A peripheral membrane protein that is interactive with lymphocytic choriomeningitis virus (LCMV) was purified from cells permissive to infection. Tryptic peptides from this protein were determined to be alpha-dystroglycan (alpha-DG). Several strains of LCMV and other arenaviruses, including Lassa fever virus (LFV), Oliveros, and Mobala, bound to purified alpha-DG protein. Soluble alpha-DG blocked both LCMV and LFV infection. Cells bearing a null mutation of the gene encoding DG were resistant to LCMV infection, and reconstitution of DG expression in null mutant cells restored susceptibility to LCMV infection. Thus, alpha-DG is a cellular receptor for both LCMV and LFV.     

Concurrent dengue hemorrhagic fever and typhoid fever infection in adult: case report

In Indonesia as well as in many developing countries both typhoid fever and dengue hemorrhagic fever (DHF) are still endemic and prevalent. In Indonesia the incidence of DHF in 1994 was 9.72/100,000 population with CFR of 2.5% and each year about 640,000-1,500,000 cases of typhoid fever were reported with mortality of 1.6-3%. The concurrent infection of both diseases may occur in one patient.     

Fibrinogen metabolism and disseminated intravascular coagulation in dengue hemorrhagic fever

In 29 patients with dengue hemorrhagic fever (DHF), 12 with grade 2 and 17 with grades 3 and 4, fibrinogen metabolism was studied by using 125I-fibrinogen; 11 of these patients were studied during shock. Hemostatic studies were also performed to search for evidence of disseminated intravascular coagulation (DIC). Increased intravascular coagulation, as judged by rapid T1/2 of 125I-fibrinogen, as well as evidence of DIC by hemostatic patients with DHF grade 2 had rapid T1/2 and only 17% had DIC. Of the 11 patients studied during shock, 91% had both rapid T1/2 and evidence of DIC, whereas 63% of the 18 patients without shock had rapid T1/2 and only 11% of this latter group had DIC. A correlation between the increased fibrinogen consumption as judged by rapid T1/2 of 125I-fibrinogen, DIC, clinical severity, and shock was demonstrated. The role of DIC in the pathogenesis of DHF is discussed, and heparin is suggested for patients with prolonged shock and severe acidosis when DIC becomes clinically apparent.     

Viral causes of tonsillitis and fever unresponsive to antibiotic therapy

This is a case report of a patient who prematurely terminated two previous magnetic resonance imaging procedures because of his highly claustrophobic condition. The patient was induced into a hypnotic trance twice before his third magnetic resonance imaging examination and he was given posthypnotic suggestions for decreased anxiety and increased physiologic control. Using a communication device with headphones on the patient, he was induced into a trance as he entered the magnet. This patient was successfully able to cope with this procedure and reported great satisfaction with treatment.     

Acute renal insufficiency in hemorrhagic fever with renal syndrome

PURPOSE: Propranolol, a beta-adrenergic antagonist, has been shown to block hyperthermically-induced ocular recurrence of HSV-1 in mice and reduce spontaneous ocular viral shedding and herpetic corneal lesions in latently infected rabbits. The present study was performed to determine the effect of propranolol on epinephrine iontophoresis-induced ocular recurrence and immunosuppression-induced ocular recurrence in the rabbit eye model. METHODS: New Zealand white rabbits were infected with HSV-1 strain 17Syn+ or McKrae. After latency was established, the animals were injected intramuscularly with saline (placebo), or propranolol (5-200 mg/kg) twice daily, and then induced with epinephrine iontophoresis or cyclophosphamide and dexamethasone administration. Tear film swabs were cultured to determine the frequency of viral shedding. RESULTS: Propranolol administered at a range of doses did not affect the frequency or duration of viral shedding following epinephrine or cyclophosphamide/dexamethasone induction as compared to saline treatment. CONCLUSION: These results demonstrate that propranolol does not significantly reduce ocular HSV-1 shedding following induction by epinephrine iontophoresis or immunosuppression. By inference, these results suggest two possibilities: (1) that viral pathways leading to spontaneous and induced shedding of virus are under separate control mechanisms or (2) in rabbits, these inducers are of such potency that propranolol is ineffectual.     

Elevated levels of IL-8 in dengue hemorrhagic fever

AIMS: To characterise retinal function using electrophysiological and psychophysical tests in 17 patients with helicoidal peripapillary chorioretinal degeneration. METHODS: The electroretinogram (ERG) was recorded using gold foil corneal electrodes. The electro-oculogram (EOG) was recorded using a standard protocol. Dark adaptometry was recorded with an SST-1 dark adaptometer and colour vision assessed with Ishihara plates and Farnsworth D-15. RESULTS: All subjects had a recordable ERG. The amplitudes and implicit times of the a- and b-waves were within normal limits at all luminances in five subjects (age 21-70 years, mean 40 years). The ERG of six (age 26-55 years, mean 40.7 years) had subnormal amplitudes at all luminances, but normal implicit times, and six (age 38-81 years, mean 60.7 years) had abnormal ERGs with marked reduction of a- and b-waves, and delayed implicit times of the b-wave. The implicit times of the a-wave were normal in all subjects. A reduction in the b/a wave ratios was not found, nor was there selective loss of scotopic, mixed rod/cone, or cone responses. The light/dark ratio of the EOG was subnormal (150-185%) or abnormal (below 150%) in all but three subjects. Two patients with normal EOG showed normal ERGs in both eyes, but one had subnormal ERGs in both eyes. The scotopic sensitivity was normal in all subjects and dark adaptation showed a normal time course. Colour vision was normal in all patients. CONCLUSION: The results suggest that in most cases the function of the retinal pigment epithelium is affected by this disease before any changes in the function of the sensory retina are detectable by our methods, and that retinal dysfunction is focal rather than diffuse.     

Infectious bursal disease and hemorrhagic enteritis

Infectious bursal disease (IBD) of chickens and hemorrhagic enteritis (HE) of turkeys are caused by infectious bursal disease virus (IBDV) and hemorrhagic enteritis virus (HEV), respectively. Both diseases have common features, including an acute stage followed by immunosuppression, resulting in lowered resistance to a variety of infectious agents and poor response to commonly used vaccines. The IBDV and HEV infections are widespread in commercial chicken and turkey flocks, respectively. The acute stage of the disease, the immunosuppression that follows, and the widespread distribution of both diseases, are major factors contributing to the economic significance of both diseases. The mechanism of immunosuppression for both infections has similarities, both affect lymphocytes and macrophages, and both are lymphocidal. In this report, an overview of both diseases with emphasis on some of the recent findings will be presented. There has been greater research activity on IBD than on HE, reflecting the relative economic importance of the species affected and the recent changes in the antigenic make up and pathogenicity of the IBDV.     

Analysis of simian hemorrhagic fever virus (SHFV) subgenomic RNAs, junction sequences, and 5' leader

Full-length simian hemorrhagic fever virus (SHFV) genome RNA (about 15 kb in length) and six subgenomic RNAs, ranging in size from 0.65 to 4.7 kb, were detected by Northern blot hybridization in MA104 cytoplasmic extracts with a 3' genomic antisense probe. The 5' regions of the two smallest subgenomic RNAs (RNAs 6 and 7) were cloned and sequenced. Sequence analysis indicated that these two RNAs contained a common 5' leader sequence joined to the subgenomic RNA bodies via a highly conserved junction sequence; the junction sequence of RNA 7 was 5'-TTAACC-3', while that of RNA 6 was 5'-TCAACC-3'. The complete 5' leader sequence (208 nt) was obtained from genomic RNA. The genomic 5' junction sequence is identical to that of RNA 7. Northern blot hybridization with an antisense 5' leader probe confirmed the presence of the complete leader sequence in all six species of subgenomic RNA. In its virion morphology, genome size, gene order, and replication strategy, SHFV is most similar to viruses such as equine arteritis virus, lactate dehydrogenase-elevating virus, and Lelystad virus/porcine respiratory and reproductive syndrome virus.     

The clinico-epidemiological characteristics of Omsk hemorrhagic fever in 1988-1992

Materials on morbidity in Omsk hemorrhagic fever at the period of 1988-1992 in the districts of the Novosibirsk region are presented. Cases of the disease were registered mainly in September-October (83.3% of cases). Transmission of the disease by contact played the leading role in the epidemiology of Omsk hemorrhagic fever. The disease took the course of medium severity with faintly pronounced hemorrhagic syndrome.     

Gallbladder wall thickening in dengue hemorrhagic fever: an ultrasonographic study

This study attempts to investigate whether gallbladder wall thickening (GBWT) measured by ultrasonography can be used in children as a reliable criterion to predict the onset of severe dengue hemorrhage fever (DHF). In this prospective study, we performed ultrasound examinations focusing on the gallbladder wall and the presence of intraperitoneal free fluid in 48 mild DHF cases (grades I-II) and 48 severe cases (grades III-IV). GBWT varied between 1 mm and 8 mm with a mean of 3.77 mm +/- 2.04 mm. The mean value of DHF grades I and II (2.39 mm +/- 1.48 mm) is significantly lower than that of grades III and IV (5.14 mm +/- 1.54 mm), p < 0.001. GBWT exceeded 3 mm in only 16 of 48 (33.3%) grade I-II patients and in 45 of 48 (93.8%) grade III-IV patients. A significant positive correlation was apparent between GBWT and the severity of illness, p < 0.001. Patients with ascites have significantly thicker gallbladder walls than those without, p < 0.01. In clinically confirmed DHF cases, the sonographic finding of GBWT > 3 mm to 5 mm, with 93.8% sensitivity, can be used as a criterion indicating the need for admission and monitoring. A GBWT of > or = 5 mm, with 91.7% specificity, is useful as a criterion for identifying DHF patients at high risk of developing hypovolemic shock.     

Marburg and Ebola hemorrhagic fevers: does the primary course of infection depend on the accessibility of organ-specific macrophages?

The consistency of measures from informants' report and from objective testing, both incorporated into the CAMDEX interview, was tested for elderly persons with mild dementia (n = 46), with moderate dementia (n = 41), and without cognitive impairment (controls, n = 56). Informants' reports permitted grading severity of dementia and provided measures of memory and mental functioning in everyday activities highly related to indices derived from objective testing.