Distinct phenotype of SARS-CoV-2 Omicron BA.1 in human primary cells but no increased host range in cell lines of putative mammalian reservoir species

SARS-CoV-2's genetic plasticity has led to several variants of concern (VOCs). Here we studied replicative capacity for seven SARS-CoV-2 isolates (B.1, Alpha, Beta, Gamma, Delta, Zeta, and Omicron BA.1) in primary reconstituted airway epithelia (HAE) and lung-derived cell lines. Furthermore, to investigate the host range of Delta and Omicron compared to ancestral SARS-CoV-2, we assessed replication in 17 cell lines from 11 non-primate mammalian species, including bats, rodents, insectivores and carnivores. Only Omicron's phenotype differed in vitro, with rapid but short replication and efficient production of infectious virus in nasal HAEs, in contrast to other VOCs, but not in lung cell lines. No increased infection efficiency for other species was observed, but Delta and Omicron infection efficiency was increased in A549 cells. Notably replication in A549 and Calu3 cells was lower than in nasal HAE. Our results suggest better adaptation of VOCs towards humans, without an extended host range, and may be relevant to the search for the putative intermediate host and reservoirs prior to the pandemic.

Poxvirus sensitivity of a novel diploid sheep embryonic heart cell line

Lumpy skin disease virus (LSDV), camelpox virus (CPV), and orf virus (ORFV) are members of the family Poxviridae. These viruses are usually isolated or produced in embryonated eggs or primary cells because continuous cell lines are less sensitive to infection. Disadvantages of the use of eggs or primary cells include limited availability, potential endogenous contaminants, and a limited ability to perform multiple passages. In this study, we developed a diploid cell culture from sheep embryonic hearts (EHs) and demonstrated its high proliferative and long-term storage capacities. In addition, we demonstrated its sensitivity to representatives of three genera of the family Poxviridae: Capripoxvirus (LSDV), Orthopoxvirus (CPV), and Parapoxvirus (ORFV). The cell culture had a doubling time of 24 h and reached 40 passages with satisfactory yield. This is comparable to that observed in primary lamb testis (LT) cells at passage 5 (P5). After infection, each poxvirus titer was 7.0-7.6 log TCID50/mL for up to five passages and approximately 6.8, 6.4, and 5.6 for the three viruses at P6-P25, P30, and P40, respectively. The sensitivity of sheep EH cells to poxvirus infection did not decrease after long-term storage in liquid nitrogen and was higher than that of primary LT cells, which are used for capripoxvirus and parapoxvirus detection and growth, and Vero cells, which are used for orthopoxvirus detection and growth. Thus, EH diploid cells are useful for poxvirus isolation and production without embryonated eggs or primary cells.

Limited permissibility of ENL-R and Mv-1-Lu mink cell lines to SARS-CoV-2

The SARS-CoV-2 pandemic started in the end of 2019 in Wuhan, China, which highlighted the scenario of frequent cross-species transmission events. From the outbreak possibly initiated by viral spill-over into humans from an animal reservoir, now we face the human host moving globally while interacting with domesticated and peridomestic animals. The emergence of a new virus into the ecosystem leads to selecting forces and species-specific adaptations. The adaptation of SARS-CoV-2 to other animals represents a risk to controlling the dissemination of this coronavirus and the emergence of new variants. Since 2020, several mink farms in Europe and the United States have had SARS-CoV-2 outbreaks with human–mink and mink–human transmission, where the mink-selected variants possibly hold evolutionary concerning advantages. Here we investigated the permissibility of mink lung-derived cells using two cell lines, Mv-1-Lu and ENL-R, against several lineages of SARS-CoV-2, including some classified as variants of concern. The viral release rate and the infectious titers indicate that these cells support infections by different SARS-CoV-2 lineages. The viral production occurs in the first few days after infection with the low viral release by these mink cells, which is often absent for the omicron variant for lung cells. The electron microscopy reveals that during the viral replication cycle, the endomembrane system of the mink-host cell undergoes typical changes while the viral particles are produced, especially in the first days of infection. Therefore, even if limited, mink lung cells may represent a selecting source for SARS-CoV-2 variants, impacting their transmissibility and pathogenicity and making it difficult to control this new coronavirus.

Evaluation of ELISA and VNT for sheeppox virus antibody detection and development of an immunoenzymatic quantitative method

Vaccination against sheep pox (SPV) is the most efficient tool to control spread of the disease and virus neutralization test (VNT) is the gold standard for vaccination monitoring. In the presented study, we evaluated the use of ELISA and VNT for quantification of SPV humoral response post vaccination. Results confirmed that VNT is more sensitive since ELISA did not detect 22% of positive tested sera, and VNT weak positive sera were either negative or doubtful by ELISA. The most sensitive cells to perform VNT were ESH-L instead of Lamb primary cells. We also investigated immunoperoxidase IPMA and immunofluorescence IFA assays for detection of SPV specific antibodies and IPMA showed higher antibody titers comparatively to IFA. VNT using ESH-L cells with immune-enzymatic revelation provide specific quantitative SPV antibody titers, easier to read in shorter incubation time.

Replication of Rift Valley Fever Virus in Amphibian and Reptile-Derived Cell Lines

Rift Valley fever phlebovirus (RVFV) is a zoonotic arthropod-borne virus, which has led to devastating epidemics in African countries and on the Arabian Peninsula. Results of in-vivo, in-vitro and field studies suggested that amphibians and reptiles may play a role as reservoir hosts of RVFV, promoting its maintenance during inter-epidemic periods. To elucidate this hypothesis, we examined two newly established reptile-derived cell lines (Egyptian cobra and Chinese pond turtle) and five previously generated reptile- and amphibian-derived cell lines for their replicative capacity for three low- and high-pathogenic RVFV strains. At different time points after infection, viral loads (TCID₅₀), genome loads and the presence of intracellular viral antigen (immunofluorescence) were assessed. Additionally, the influence of temperatures on the replication was examined. Except for one cell line (read-eared slider), all seven cell lines were infected by all three RVFV strains. Two different terrapin-derived cell lines (Common box turtle, Chinese pond turtle) were highly susceptible. A temperature-dependent replication of RVFV was detected for both amphibian and reptile cells. In conclusion, the results of this study indicate the general permissiveness of amphibian and reptile cell lines to RVFV and propose a potential involvement of terrapins in the virus ecology.

Comparative sensitivity study of primary cells, vero, OA3.Ts and ESH-L cell lines to lumpy skin disease, sheeppox, and goatpox viruses detection and growth

Lumpy skin disease virus (LSDV), sheeppox virus (SPPV) and goatpox (GTPV) virus have been usually grown on primary cells for diagnosis, production and titration purposes. The use of primary cells present several inconvenient, heavy preparation, heterogeneous cell population, non-reproducible viral titration and presence of potential endogenous contaminants. Therefore investigating sensitivity of candidate continuous cell lines is needed. In this study, we compared the above Capripox viruses (CaPVs) sensitivity of primary cells of four origin (heart, skin, testis and kidney), with three cell lines (Vero, OA3.Ts and ESH-L). We tested sensitivity for virus isolation, replication cycle and titration, revealed by cytopathic effect (CPE), immunoenzymatic staining and immunofluorescence. Our results show that ESH-L cells and primary fetal heart cells present the highest sensitivity for CaPVs growth and detection. Vero cells can replicate those viruses but without showing any CPE while the titer obtained on OA3.Ts is lower than primary and ESH-L cells. ESH-L cells are an effective alternative to primary cells use for growing Capripoxviruses and their diagnosis.

Common vole (Microtus arvalis) and bank vole (Myodes glareolus) derived permanent cell lines differ in their susceptibility and replication kinetics of animal and zoonotic viruses

Pathogenesis and reservoir host adaptation of animal and zoonotic viruses are poorly understood due to missing adequate cell culture and animal models. The bank vole (Myodes glareolus) and common vole (Microtus arvalis) serve as hosts for a variety of zoonotic pathogens. For a better understanding of virus association to a putative animal host, we generated two novel cell lines from bank voles of different evolutionary lineages and two common vole cell lines and assayed their susceptibility, replication and cytopathogenic effect (CPE) formation for rodent-borne, suspected to be rodent-associated or viruses with no obvious rodent association. Already established bank vole cell line BVK168, used as control, was susceptible to almost all viruses tested and efficiently produced infectious virus for almost all of them. The Puumala orthohantavirus strain Vranica/Hällnäs showed efficient replication in a new bank vole kidney cell line, but not in the other four bank and common vole cell lines. Tula orthohantavirus replicated in the kidney cell line of common voles, but was hampered in its replication in the other cell lines. Several zoonotic viruses, such as Cowpox virus, Vaccinia virus, Rift Valley fever virus, and Encephalomyocarditis virus 1 replicated in all cell lines with CPE formation. West Nile virus, Usutu virus, Sindbis virus and Tick-borne encephalitis virus replicated only in a part of the cell lines, perhaps indicating cell line specific factors involved in replication. Rodent specific viruses differed in their replication potential: Murine gammaherpesvirus-68 replicated in the four tested vole cell lines, whereas murine norovirus failed to infect almost all cell lines. Schmallenberg virus and Foot-and-mouth disease virus replicated in some of the cell lines, although these viruses have never been associated to rodents. In conclusion, these newly developed cell lines may represent useful tools to study virus-cell interactions and to identify and characterize host cell factors involved in replication of rodent associated viruses.

Validation of a KHV antibody enzyme-linked immunosorbent assay (ELISA)

Koi herpesvirus (KHV) causes KHV disease (KHVD). The virus is highly contagious in carp or koi and can induce a high mortality. Latency and, in some cases, a lack of signs presents a challenge for virus detection. Appropriate immunological detection methods for anti-KHV antibodies have not yet been fully validated for KHV. Therefore, it was developed and validated an enzyme-linked immunosorbent assay (ELISA) to detect KHV antibodies. The assay was optimized with respect to plates, buffers, antigens and assay conditions. It demonstrated high diagnostic and analytical sensitivity and specificity and was particularly useful at the pond or farm levels. Considering the scale of the carp and koi industry worldwide, this assay represents an important practical tool for the indirect detection of KHV, also in the absence of clinical signs.

Detection of Herpesvirus anguillae (AngHV-1) in European eel Anguilla anguilla (L.) originating from northern Poland-assessment of suitability of selected diagnostic methods

The Community Action Plan requests EU member states to implement measures that ensure the recovery of the severely depleted European eel stocks. One of the main threats is posed by Anguillid herpesvirus 1 (AngHV-1) leading to increased mortality in both wild and farmed eels. Following recommendations of the OIE to minimize the risk of obtaining false-negative results, the main aim of the study was to optimize diagnostic methods for AngHV-1 detection using conventional PCR, nested PCR and in situ hybridization assay. While 53.3% of the individual organ samples were tested positive for AngHV-1 by PCR, the additional virus analysis via nested PCR revealed that the actual prevalence was 93.3%. In the cell cultivation passages, a cytopathic effect was hardly found in the first two rounds. In the third passage onto cell cultures, a lytic CPE was detected. The identification and confirmation of the viruses obtained from cell cultures as well as directly from the organ tissues were proceeded by PCR, nested PCR and sequencing of the PCR products. While no positive signal was detectable in the first round by PCR using samples from the third cell culture passages, the nested PCR provided weak but visible positive signals.

A bovine cell line that can be infected by natural sheep scrapie prions

Cell culture systems represent a crucial part in basic prion research; yet, cell lines that are susceptible to prions, especially to field isolated prions that were not adapted to rodents, are very rare. The purpose of this study was to identify and characterize a cell line that was susceptible to ruminant-derived prions and to establish a stable prion infection within it. Based on species and tissue of origin as well as PrP expression rate, we pre-selected a total of 33 cell lines that were then challenged with natural and with mouse propagated BSE or scrapie inocula. Here, we report the successful infection of a non-transgenic bovine cell line, a sub-line of the bovine kidney cell line MDBK, with natural sheep scrapie prions. This cell line retained the scrapie infection for more than 200 passages. Selective cloning resulted in cell populations with increased accumulation of PrP^res, although this treatment was not mandatory for retaining the infection. The infection remained stable, even under suboptimal culture conditions. The resulting infectivity of the cells was confirmed by mouse bioassay (Tgbov mice, Tgshp mice). We believe that PES cells used together with other prion permissive cell lines will prove a valuable tool for ongoing efforts to understand and defeat prions and prion diseases.

Replicative Capacity of MERS Coronavirus in Livestock Cell Lines

Replicative capacity of Middle East respiratory syndrome coronavirus (MERS-CoV) was assessed in cell lines derived from livestock and peridomestic small mammals on the Arabian Peninsula. Only cell lines originating from goats and camels showed efficient replication of MERS-CoV. These results provide direction in the search for the intermediate host of MERS-CoV.

Isolation and partial characterization of a novel virus from different carp species suffering gill necrosis - ultrastructure and morphogenesis

Two isolates of a novel enveloped RNA virus were obtained from carp and koi carp with gill necrosis. Both isolates behaved identically and could be propagated in different cyprinid cell lines forming large syncytia. The virus was sensitive to lipid solvents and neither exhibited haemadsorption/haemagglutination nor reverse transcriptase activity. Mature virus particles displayed a spherical shape with diameter of 100-350 nm after negative staining and 100-300 nm in ultrathin sections, covered by short projections of 8-10 nm in length. Maturation of virus progeny was shown to occur by budding and envelopment of the filamentous helical nucleocapsids at the cell surface. A detailed comparison of ultrastructure and morphogenesis of the novel virus isolates with selected arena-, ortho- and paramyxoviruses as possible candidates for evaluation of taxonomic classification yielded no consistency in all phenotypic features. Thus, on the basis of ultrastructure the novel virus isolates could not be assigned unequivocally to any established virus family.

More novel hantaviruses and diversifying reservoir hosts--time for development of reservoir-derived cell culture models?

Due to novel, improved and high-throughput detection methods, there is a plethora of newly identified viruses within the genus Hantavirus. Furthermore, reservoir host species are increasingly recognized besides representatives of the order Rodentia, now including members of the mammalian orders Soricomorpha/Eulipotyphla and Chiroptera. Despite the great interest created by emerging zoonotic viruses, there is still a gross lack of in vitro models, which reflect the exclusive host adaptation of most zoonotic viruses. The usually narrow host range and genetic diversity of hantaviruses make them an exciting candidate for studying virus-host interactions on a cellular level. To do so, well-characterized reservoir cell lines covering a wide range of bat, insectivore and rodent species are essential. Most currently available cell culture models display a heterologous virus-host relationship and are therefore only of limited value. Here, we review the recently established approaches to generate reservoir-derived cell culture models for the in vitro study of virus-host interactions. These successfully used model systems almost exclusively originate from bats and bat-borne viruses other than hantaviruses. Therefore we propose a parallel approach for research on rodent- and insectivore-borne hantaviruses, taking the generation of novel rodent and insectivore cell lines from wildlife species into account. These cell lines would be also valuable for studies on further rodent-borne viruses, such as orthopox- and arenaviruses.

Impact of propofol on mid-latency auditory-evoked potentials in children

BACKGROUND

Propofol is increasingly used in paediatric anaesthesia, but can be challenging to titrate accurately in this group. Mid-latency auditory-evoked potentials (MLAEPs) can be used to help titrate propofol. However, the effects of propofol on MLAEP in children are unclear. Therefore, we investigated the relationship between propofol and MLAEP in children undergoing anaesthesia.

METHODS

Fourteen healthy children aged 4-16 yr received anaesthesia for elective surgery. Before surgery, propofol was administered in three concentrations (3, 6, 9 µg ml(-1)) through a target-controlled infusion pump using Kataria and colleagues' model. MLAEPs were recorded 5 min after having reached each target propofol concentration at each respective concentration. Additionally, venous propofol blood concentrations were assayed at each measuring time point.

RESULTS

Propofol increased all four MLAEP peak latencies (peaks Na, Pa, Nb, P1) in a dose-dependent manner. In addition, the differences in amplitudes were significantly smaller with increasing propofol target concentrations. The measured propofol plasma concentrations correlated positively with the latencies of the peaks Na, Pa, and Nb.

CONCLUSIONS

Propofol affects MLAEP latencies and amplitudes in children in a dose-dependent manner. MLAEP measurement might therefore be a useful tool for monitoring depth of propofol anaesthesia in children.

Effects of increasing sevoflurane MAC levels on mid-latency auditory evoked potentials in infants, schoolchildren, and the elderly

BACKGROUND

Detection of mid-latency auditory evoked potentials (MLAEPs) is a technology to monitor central nervous structures. As seen in adults and children, general anaesthesia influences the MLAEP latencies. MLAEP detection seems to be a promising tool to assess different levels of anaesthesia depth in adults and children.

METHODS

MLAEPs were recorded in 10 infants (2 months-3 yr), 12 schoolchildren (6-14 yr), and 10 elderly (75-89 yr) under general anaesthesia with increasing concentrations of sevoflurane at steady state. In addition, MLAEPs were detected before and after the application of sufentanil.

RESULTS

At all different ages, MLAEP latencies increased significantly with higher volume percentages of sevoflurane. These results were also detectable when MAC values of sevoflurane were compared with MLAEP peaks. An age-dependent effect could be displayed as elderly people need lower absolute sevoflurane concentrations to achieve the same MLAEP peak increase. Overall, the application of sufentanil under steady-state sevoflurane application at 1 MAC did not importantly affect the MLAEP latencies.

CONCLUSIONS

MLAEP latencies increase at the influence of sevoflurane in a dose-dependent manner and in relation to age. These results imply that MLAEP detection is a reasonable tool for monitoring hypnotic effects at all ages. Further studies are required to standardize MLAEP alterations related to effects of medication used for general anaesthesia at all different ages.

Susceptibility of koi x crucian carp and koi x goldfish hybrids to koi herpesvirus (KHV) and the development of KHV disease (KHVD)

Hybrids of koi, Cyprinus carpio x crucian carp, Carassius carassius and koi x goldfish, Carassius auratus, proved to be susceptible to koi herpesvirus (KHV, syn. CyHV-3) and developed KHV disease (KHVD). While hybrids of koi x goldfish were partly resistant to mortality following infection by immersion, most koi x crucian carp hybrids died after bath infection. KHV DNA was detected in dead fish but also in all surviving animals by different polymerase chain reactions (PCRs). According to these results, hybrid crossbreeding does not seem to prevent severe losses associated with KHV in terms of inducing KHVD. The present study showed severe losses after a waterborne KHV infection of between 35% and 100% in koi x goldfish and koi x crucian carp hybrids as well as in SPF carp.

Functional analysis of the pseudorabies virus UL51 protein

Homologs of the UL51 protein of herpes simplex virus have been identified in all herpesvirus subfamilies, but until now, no function has been assigned to any of them. To investigate function of the UL51 gene product of the alphaherpesvirus pseudorabies virus (PrV), we isolated and analyzed a mutant lacking the major part of the open reading frame, PrV-DeltaUL51F, and a rescuant. One-step growth analysis of PrV-DeltaUL51F revealed only slightly reduced titers, but plaque size was notably diminished and reached only approximately 30% the plaque size of wild-type PrV. Ultrastructurally, intracytoplasmic capsids were found in large numbers either without envelope or in different stages of envelopment, indicating that secondary envelopment in the cytoplasm was less efficient. However, neuroinvasion in the mouse trigeminal pathway after intranasal infection was only slightly delayed. A PrV UL11 mutant also showed a defect in secondary envelopment (M. Kopp, H. Granzow, W. Fuchs, B. G. Klupp, E. Mundt, A. Karger, and T. C. Mettenleiter, J. Virol. 77:5339-5351, 2003). Since both proteins are part of the viral tegument and are predicted to be membrane associated, they may serve similar, possibly redundant functions during viral morphogenesis. Therefore, we also isolated a mutant simultaneously lacking UL51 and UL11. This mutant exhibited further reduced plaque size compared to the single-deletion mutants, but viral titers were comparable to those for the UL11 mutant. In electron microscopic analyses, the observed defect in secondary envelopment was similar to that found in the UL11 single-deletion mutant. In conclusion, both conserved tegument proteins, either singly or in combination, are involved in virion morphogenesis in the cytoplasm but are not essential for viral replication in vitro and in vivo.

Coping of Cancer Patients During and After Radiotherapy – a Follow-Up of 2 Years

AIM

We wanted to understand coping strategies specific to different phases up to two years after radiotherapy, to identify patients who are at higher risk of mood disturbances and to characterise the association between coping strategies and psychosocial adaptation.

PATIENTS AND METHODS

From 1997 to 2001, 2,169 patients with different diagnoses were screened (27.8% refused to participate). Data of 276 patients from the beginning of radiotherapy (ti1) and 5 follow-up investigations (ti6/2 years) could be analysed. With the FKV (Freiburg Questionnaire Coping with Disease) cancer-specific coping aspects were assessed. The association between coping styles and psychosocial adaptation was evaluated using the Questionnaire on Stress in Cancer Patients (QSC) and the questionnaire on Functional Assessment of Cancer Treatment (FACT-G).

RESULTS

'Active problem-orientated' coping and 'distractions' are the most important coping strategies. Only 'active problem-orientated' and 'depressive' coping showed a significant decrease. We observed higher means on the scales of the FKV in women. Marital status (single, married, divorced/widowed) had a significant influence on active problem-orientated coping and spirituality. Age, children, education, T/M status and curative/ palliative intention of treatment had no influence on coping styles. Breast cancer patients and lymphoma patients demonstrated the highest use of coping strategies after radiotherapy with a significant decrease of 'active problem-orientated coping'. Depressive coping and minimizing importance at ti1 were associated with high psychosocial distress and low quality of life (QoL) at ti6.

CONCLUSION

The correlation of coping mechanisms at the beginning of radiotherapy with low QoL and high psychosocial stress at 2 years could help to identify patients at risk for low psychosocial adaptation. Psycho-oncologically trained teams of physicians would best correspond to this profile of needs and would contribute significantly to an ameliorated adaptation of patients to cancer which could lead to higher life satisfaction.

Quality of life (QoL) as predictive mediator variable for survival in patients with intracerebral neoplasma during radiotherapy

BACKGROUND

The prognosis for patients with malignant astrocytoma or brain metastases is often fatal despite intensive therapy. Therefore we wished to elucidate whether the quality of life (QoL) is a determinant of overall survival (OAS).

PATIENTS AND METHODS

From 1997 to 2000 153 patients with brain tumours were screened; 39 patients (26%) refused to participate and further 47 patients were excluded (cerebral impairment 14%, amaurosis/ language problems 3%, Karnofsky performance score < 50% 7%, death 8%, non-compliance 7%). Thus, 57 patients were analysed (33 with primary brain tumours, 24 with brain metastases). With the FACT-G questionnaire cancer-specific aspects of health-related QoL were assessed.

RESULTS

Patients with metastases showed a lower QoL in the physical sphere than patients with astrocytoma, but there were no significant differences in OAS. Median survival of patients with good QoL was 31.3 months versus 14.2 months in patients with bad QoL. Only the two variables 'living with a spouse' and FACT-G sum score had a statistically significant influence on survival (p = 0.033 and p = 0.003) modelled by the Cox-PH regression. Patients who did not live with a spouse had shorter survival times than the other patients.

CONCLUSION

Health-related QoL can serve to identify a patient group with higher risks of death.

Detection of European porcine reproductive and respiratory syndrome virus in porcine alveolar macrophages by two-colour immunofluorescence and in-situ hybridization-immunohistochemistry double labelling

Two groups of five pigs aged 6 weeks were each infected oronasally with one of two different European isolates of porcine reproductive and respiratory syndrome virus (PRRSV). The animals were killed sequentially at 4, 7, 14 or 21 days post-inoculation for examination. The methods used consisted of histopathology, and mono- and double-labelling techniques based on in-situ hybridization, immunofluorescence and immunohistochemistry. Porcine alveolar macrophages (PAMs) contained large amounts of PRRSV antigen and PRRSV RNA, as shown by double labelling with (1) either PRRSV immunofluorescence or PRRSV-specific in-situ hybridization with digoxigenin-labelled riboprobes, and (2) immunolabelling with Mac 387 antibody for calprotectin. Expression of PRRSV-RNA was not detectable in cytokeratin-positive hypertrophic and proliferating pneumocytes or in cells of alveolar ducts or bronchiolar epithelium. The use of two-colour immunofluorescence with confocal laser scanning microscopy and double labelling with in-situ hybridization-immunohistochemistry showed that PAMs were the only pulmonary target cells. This contradicts earlier reports that epithelial pulmonary cells may also be infected by PRRSV.

Role of adenosine in the diagnosis and treatment of tachyarrhythmias in pediatric patients

Tachyarrhythmias are common rhythm disturbances in infants and children. Despite the availability of diagnostic criteria arrhythmias are sometimes commonly misdiagnosed. Recent reports suggest that an endogenous purine nucleoside, adenosine, has a diagnostic effect in narrow QRS complex tachycardias, in addition to terminating supraventricular tachycardia involving the atrioventricular node. This report reviews the authors' experience with the use of adenosine for diagnosis of narrow and wide complex tachyarrhythmias in children. Adenosine was administered to 43 patients with several types of tachyarrhythmias (mean age, 8.3 +/- 5.24 years). Nineteen patients had structural or acquired heart disease. Of the 43 patients there were 28 (65%) several different types of narrow QRS complex tachycardia and 14 (33%) ventricular arrhythmias. One patient (2%) had long QT. Adenosine terminated supraventricular tachycardia, in 11 of 12 patients (92%), ventricular tachycardia in five of eight patients (63%), and transiently terminated premature ventricular contractions in two of six patients (33%). The diagnostic ability of adenosine was perfect in eight supraventricular tachycardia. In these eight cases the tachycardia mechanism was unclear before the administration of adenosine, which demonstrated three cases of sinus tachycardia, three of atrial flutter, one of atrial fibrillation and one of atrial fibrilloflutter. Confirmation of the primary diagnosis by adenosine was perfect in five tachyarrhythmias including three cases of atrial flutter, one of atrial fibrillation and one of ectopic atrial tachycardia. The average effective dose of adenosine was 212 micrograms/kg (range, 100-400 micrograms/kg). There were no serious side-effects except transient dyspnea, chest pain and flushing. These findings demonstrate adenosine to be helpful and safe in the diagnosis of tachyarrhythmias.

The role of serotonin re-uptake inhibitors in preventing recurrent unexplained childhood syncope -- a preliminary report

To assess the efficacy of a serotonin re-uptake inhibitor, sertraline hydrochloride, in preventing recurrent neurocardiogenic syncope, we studied 15 patients (10 female; mean age 12.9 +/- 2 years) with positive head-upright tilt test and resistant to standard pharmacotherapy, atenolol or disopyramide. The patients were given 50 mg oral sertraline hydrochloride daily for 6 weeks. Intolerance to the drug was seen in 3 patients and 2 had syncopal episodes during the therapy. A head-upright tilt table test was then repeated in 10 patients. Six were tilt negative and asymptomatic over a mean follow up period of 7 +/- 3 months while four remained tilt positive: two experienced marked hypotension and bradycardia, characterized as mixed type syncope, and two had cardiac asystole, lasting > 10 s, during tilting, thereby exhibiting a cardio-inhibitory response.

CONCLUSION

Sertraline hydrochloride may be useful in preventing recurrent neurocardiogenic syncope resistant to standard pharmacotherapy but careful clinical studies are essential before such a treatment strategy can be recommended since serious asystole could develop.

Comparison of sensitivity and specificity of tilt protocols with and without isoproterenol in children with unexplained syncope

Head-up tilt testing with or without isoproterenol is extensively used in the evaluation of patients with unexplained syncope. However, sensitivity and specificity of tilt protocols with and without isoproterenol have not been clarified in children, due to lack of age matched control subjects. This study was designed to assess and to compare the sensitivity and specificity of tilting alone and tilting in conjunction with isoproterenol. Thirty children with unexplained syncope (group I) and 15 age-matched control subjects (control group I) underwent successive 60 degrees head-up tilts for 10 minutes during infusions of 0.02, 0.04, and 0.06 microgram/kg/min of isoproterenol, after a baseline tilt to 60 degrees for 25 minutes. Also, 35 children (group II) with unexplained syncope and 15 healthy control subjects (control group II) were evaluated by head-up tilt to 60 degrees for 45 minutes without an infusion of isoproterenol. In response to tilt protocol with graded isoproterenol, 23 (76.6%) of the patients in group I and 2 of the 15 (13.3%) control subjects developed syncope. Accordingly, the sensitivity of tilt testing with isoproterenol was 76.6%, and its specificity was 86.7%. Tilt testing without isoproterenol was positive in 17 (48.5%) of the patients in group II but in only 1 of the 15 (6.6%) control subjects. Thus, sensitivity and specificity of tilt testing without isoproterenol were 48.5% and 93.4%, respectively. The mean heart rate and systolic blood pressure decreased significantly (P < 0.001) in all tilt positive patients during syncope. In conclusion, the head-up tilt test is a valuable diagnostic test in the evaluation of children with unexplained syncope, and isoproterenol is likely to increase the sensitivity of the test without decreasing its specificity.

The pseudorabies virus UL51 gene product is a 30-kilodalton virion component

Positional homologs to the UL51 open reading frame of herpes simplex virus type 1 have been identified throughout the herpesvirus family. However, no respective protein has so far been described for any of the herpesviruses. With rabbit antisera directed against oligopeptides predicted to comprise antigenic regions of the deduced pseudorabies virus (PrV) UL51 protein, a polypeptide with a size of 30 kDa was identified in PrV-infected cell lysates and in purified virions. This molecular mass correlates reasonably well with the predicted mass of 25 kDa of the 236-amino-acid deduced UL51 protein. Antisera raised against peptides derived from different predicted antigenic regions all detected the 30-kDa protein in Western blot (immunoblot) analyses. Specificity was ascertained by peptide competition. Subcellular fractionation showed the presence of the UL51 protein mainly in the nucleus of infected cells. After separation of purified virion preparations into envelope and capsid, the PrV UL51 protein was detected in the capsid fraction. In summary, we identified the first herpesvirus UL51 protein and demonstrate that it represents a structural component of PrV virions.

Transcatheter closure of patent ductus arteriosus using controlled-release coils

Controlled-release coils have become available recently for the closure of patent ductus arteriosus (PDA). Transcatheter closure of patent arterial ducts was attempted in 13 patients, ranging in age from 5 months to 15 years, mean 4.1 years. Implantation of controlled-release PDA coils was attempted via the femoral artery through 5 Fr catheters in all cases except one, in whom both the femoral arterial and venous routes were used. The procedure was successful in 10 of the 13 patients. In these, the pulmonary artery systolic pressure ranged between 25 and 42 mmHg and the duct diameter varied from 1.5 to 6 mm at its narrowest point. Six of the patients received a single coil. Two coils were inserted in three patients and three coils in one patient. In three patients the ducts were too large for safe release of the coils, despite attempted implantation of up to three coils simultaneously. These coils were easily withdrawn into the catheter. Immediately at the end of the procedure, the duct was completely occluded in nine of the 10 patients, and in one patient there was a small residual flow. The procedure time varied between 35 min and 2.5 h, mean 81 min and the fluoroscopy time varied from 5 to 78 min, mean 25 min. None of the patients experienced hemorrhage, diminished lower extremity pulse, hemolysis or infection. In one patient, a 5 mm coil embolized into the right pulmonary artery soon after release. It was retrieved with a snare, then 8 mm and a 5 mm coil were implanted satisfactorily in the arterial duct. At follow-up by color Doppler echocardiography, the duct was completely occluded in all patients. Transcatheter closure of patent arterial ducts by controlled-release PDA coils is effective and safe. Even when more than one coil is inserted, it is still cheaper than transcatheter umbrella closure. This method is therefore of great value, particularly in less affluent countries.