Recurrent wheezy bronchitis and viral respiratory infections

Fifty four patients aged from 1 to 6 years who had had recurrent attacks of wheezy bronchitis were prospectively followed up for three months to find out if there was an association between different viral respiratory infections and episodes of wheezing. Of the 115 episodes of upper or lower respiratory tract symptoms, virus or Mycoplasma pneumoniae infection were diagnosed in 52 (45%). Thirty four of rhinoviruses. The patients had an average of 2.1 episodes of respiratory tract symptoms the total mean (SD) duration of which was 30 (2) days of the 92 days that followed. Wheezing occurred during 76 (66%) of the 115 episodes and during a third of these the patient was admitted to hospital because of severe dyspnoea. Wheezing started a mean (SD) of 43 (7) hours after the first symptoms of respiratory infection and persisted for 3.8 (4.2) days in patients in whom virus infection was diagnosed. The incidence of wheezing was not associated with IgE mediated atopy, with positive virological tests, or with fever during virus infection, but was associated with parental smoking and more than one sibling.

Clinical role of respiratory virus infection in acute otitis media

The clinical characteristics of acute otitis media in relation to coexisting respiratory virus infection were studied in a 1-year prospective study of 363 children with acute otitis media. Respiratory viruses were detected using virus isolation and virus antigen detection in nasopharyngeal specimens of 42% of the patients at the time of diagnosis. Rhinovirus (24%) and respiratory syncytial virus (13%) were the two most common viruses detected. Adenovirus, parainfluenza viruses, and coronavirus OC43 were found less frequently. The mean duration of preceding symptoms was 5.9 days before the diagnosis of acute otitis media. Ninety-four percent of the children had symptoms of upper respiratory tract infection. Fever was reported in 55% and earache in 47% of cases. Patients with respiratory syncytial virus infection had fever, cough, and vomiting significantly more often than patients with rhinovirus infection or virus-negative patients. No significant differences were found in the appearance of the tympanic membrane and outcome of illness between virus-negative and virus-positive patients with acute otitis. Most patients respond well to antimicrobial therapy despite the coexisting viral infection. If the symptoms of infection persist, they can be due to the underlying viral infection, and viral diagnostics preferably with rapid methods may be clinically useful in these patients.

Viral lower respiratory tract infections in Filipino children

Viral causes of acute lower respiratory tract infection were studied prospectively between 15 June and 31 October 1984 in 312 Filipino children less than 5 years old living in periurban slums and middle-class housing. The cause was based on viral antigen detection, virus isolation, and antibody assays. There were 131 children (41.2%) who were admitted to the hospital, and 150 (47%) had an infiltrate on chest radiograph. A total of 198 viral infections were confirmed in 162 patients (51.9%), 42.3% with single viral infection and 9.6% with mixed (two or more) infection. The infections were measles (21.4%), influenza A (15.9%), parainfluenza types 1, 2, and 3 (8.8%), respiratory syncytial virus (7.1%), influenza B (5.8%), enteroviruses (5.1%), adenoviruses (3.9%), herpes simplex virus (1.6%), and cytomegalovirus (1.3%). Viral infections other than measles were seen in 39.7% of the cases. The presence of viral infection correlated with better nutritional status. Influenza A or B diagnosis was associated with mild forms of acute respiratory tract infection, measles and a preceding rash with severe disease.

Prevalence of human rotavirus serotypes in some European countries 1981-1988

An extended epidemiological survey on the circulation of the 4 established human rotavirus (HRV) serotypes in some European countries was carried out on 831 fecal strains collected from infants and young children with acute non-bacterial gastroenteritis during 1981-88. Typing was done by enzyme-linked immunosorbent assay and/or solid-phase immune electron microscopy using VP7 type-specific neutralizing monoclonal antibodies. Serotype 1 HRV strains were found to be largely predominant in this period both in Italy and other countries, whereas serotype 4 strains were less common. The number of strains of serotypes 1 and 4 circulating in Europe was equivalent only in 1983-84. Serotype 2 strains were significantly represented only in 1981-84, while strains of serotype 3 were nearly absent, since only 8 strains (2 of which belonged to subgroup I) were found during the entire study period. About 10% of strains could not be typed, while 9 strains exhibited dual VP7 reactivity and 6 were non-group A HRVs. These epidemiological findings must be taken into consideration when deciding strategies for preparing vaccines to be used in Europe.

Acute otitis media and respiratory virus infections

We studied the association of acute otitis media with different respiratory virus infections in a pediatric department on the basis of epidemics between 1980 and 1985. Altogether 4524 cases of acute otitis media were diagnosed. The diagnosis was confirmed by tympanocentesis in 3332 ears. Respiratory virus infection was diagnosed during the same period in 989 patients by detecting viral antigen in nasopharyngeal mucus. There was a significant correlation between acute otitis media and respiratory virus epidemics, especially respiratory syncytial virus epidemics. There was no significant correlation between outbreaks of other respiratory viruses and acute otitis media. Acute otitis media was diagnosed in 57% of respiratory syncytial virus, 35% of influenza A virus, 33% of parainfluenza type 3 virus, 30% of adenovirus, 28% of parainfluenza type 1 virus, 18% of influenza B virus and 10% of parainfluenza type 2 virus infections. These observations show a clear association of respiratory virus infections with acute otitis media. In this study on hospitalized children Haemophilus influenzae strains were the most common bacteriologic pathogens in middle ear fluid, occurring in 19% of cases. Streptococcus pneumoniae was present in 16% and Branhamella catarrhalis in 7% of cases. There was no association between specific viruses and bacteria observed in this study.

Immunoassay for serologic diagnosis of influenza type A using recombinant DNA produced nucleoprotein antigen and monoclonal antibody to human IgG

Influenza type A nucleoprotein (NP) derived from the full length cloned gene expressed in E. coli was evaluated in a solid phase enzyme immunoassay (EIA) for detection of human antibody to influenza. Monoclonal antibody to human IgG was used for detection. Direct and indirect assays were developed and sera were tested in serial and single dilution formats. Preliminary results indicated that recombinant-and virion-derived NP antigens were comparable in binding ability to plastic and binding human antibody. Eighty-seven paired sera from influenza patients were tested. The most sensitive assay (indirect-serial dilution) detected 56 (64%) rises and the simplest assay (direct-single dilution) detected 43 (49%) rises, compared to 36 (41%) for complement fixation. Paired sera from 18 control patients showed no evidence of antibody rises by any of the assays. Forty-nine paired sera from influenza B infected patients were negative for antibody rises except for one borderline rise by the indirect-serial dilution assay. These results indicate that the use of recombinant DNA derived nucleoprotein for immunoassay is feasible. The sensitivity of immunoassays using NP adsorbed to the solid phase and monoclonal antibody specific for human IgG to detect bound antibody exceeded that of conventional complement fixation testing for establishing serologic evidence of influenza type A infection.

One-incubation time-resolved fluoroimmunoassay based on monoclonal antibodies in detection of influenza A and B viruses directly in clinical specimens

A new modified enzyme immunoassay screening method was developed for testing hybridoma cultures, so as to select antibodies useful for solid phase assays. Samples of hybridoma cultures were incubated for 1 h with purified nucleoprotein preparation in microtiter wells precoated with rabbit anti-influenza A or B immunoglobulin, followed by washing and addition of anti-mouse HRPO-conjugate. The monoclonal antibodies were then used in one-incubation time-resolved fluoroimmunoassay (TR-FIA) for detecting influenza viral proteins in nasopharyngeal aspirate specimens. The sample and europium (Eu)-labelled monoclonal detector antibody (100 microliter of each) were added simultaneously to microtiter wells precoated with anti-virus monoclonal antibody, and incubated for 1 h. After washing and addition of the enhancement solution the strips were shaken for 10 min before measurement of the fluorescence using a photon counting fluorometer. All of the monoclonal antibodies screened by our modified method and Eu-labelled worked as detector antibodies. Many of these monoclones also functioned as capture antibodies on solid phase. A total number of 309 (influenza A) and 104 (influenza B) nasopharyngeal aspirate specimens taken mainly from hospitalized children with acute respiratory disease were tested with the TR-FIA, using monoclonal antibodies produced by our modified screening method in comparison with monoclonal antibodies previously reported elsewhere (Walls et al., 1986). Results were similar, and superior to those obtained with routinely used indirect enzyme immunoassay based on polyclonal antibodies. The results of this study indicate that the one-incubation TR-FIA using monoclonal antibodies selected by the modified screening method is a highly sensitive and rapid method for detecting influenza A and influenza B virus in clinical specimens.

Time-resolved fluoroimmunoassay compared with virus isolation for rapid detection of respiratory syncytial virus in nasopharyngeal aspirates

Two monoclonal antibodies against two distinct conserved epitopes of the respiratory syncytial virus (RSV) nucleocapsid protein were used in a direct time-resolved fluoroimmunoassay (TR-FIA) for the detection of RSV antigens in nasopharyngeal aspirates. The capture antibody was adsorbed to the solid phase of microdilution strip wells, and the indicator antibody was labeled with a europium chelate. Specimens and label were incubated simultaneously for 1 h at 37 degrees C in the coated wells. After the test samples were washed, fluorescence enhancement solution was added, strips were shaken, and the time-resolved fluorescence was measured. The test procedure took only 75 min, and the total time for 20 specimens, with pretreatment by sonication, was 2 to 3 h. We prospectively evaluated the detection of RSV in nasopharyngeal aspirates of pediatric patients by TR-FIA and by virus isolation in human diploid fibroblasts. TR-FIA detected 40 of 42 isolation-positive specimens. Nine additional isolation-negative specimens were positive by TR-FIA; all proved to be true positives by a blocking-type confirmatory assay. The sensitivity, specificity, positive predictive value, and negative predictive value for TR-FIA were 95, 96, 82, and 99%, respectively, of the values obtained by virus isolation and 96, 100, 100, and 99%, respectively, of the values obtained by virus isolation and the confirmatory assay.

The conduction velocities of peripheral nerve fibres conveying sensations of warming and cooling

With the current practice of measuring thresholds for warming and cooling separately, the question of the exact nature of afferents subserving these sensations assumes new importance. Experiments to measure reaction times to warming and cooling stimuli at two sites on the lower limb are described. The conduction velocity for each sensation was estimated from the conduction distance and conduction time in the limb. The estimated mean conduction velocity for warming was 0.5, SD 0.2 m/s and cooling 2.1, SD 0.8 m/s. These figures confirm that the sensation of warming is conveyed in unmyelinated and cooling in small myelinated peripheral nerve fibres.

The role of parainfluenza viruses in inspiratory difficulties in children

Viral findings were prospectively studied in middle and lower respiratory tract infections in 449 hospitalized children during a 12-month follow-up period. A viral aetiology was found in 30 of the 65 children (46%) with inspiratory difficulties. Parainfluenza viruses were the infective agents in 24 of the 30 cases with viral diagnoses (80%), type 2 being the most prominent. There were 38 cases of parainfluenza infections, type 2 being the infective agent in 58% of the 24 cases of parainfluenza infections with inspiratory difficulties but in only 21% of the 14 cases of parainfluenza infections without inspiratory difficulties. Type 2 parainfluenza virus produced inspiratory difficulties in 82% of the cases as opposed to 56 and 50% of the cases for type 1 and 3, respectively. It is concluded that the type 2 parainfluenza virus has a particular association with inspiratory difficulties in children. Viral diagnosis was reached using direct antigen detection in nasopharyngeal specimens by radioimmunoassay in 59% and using complement fixation serology in 76% of parainfluenza infections. Direct antigen detection was especially useful in infants. We suggest that direct antigen detection should be used as a primary virological diagnostic method in small children with middle and lower respiratory tract infections.

Functional disturbances of the masticatory system related to temporomandibular joint involvement by rheumatoid arthritis

Several theories have been proposed concerning the aetiology of dysfunction of the temporomandibular joint (TMJ). To analyse the relationship of radiographic changes to clinical signs and symptoms of TMJ dysfunction, the present study was conducted in subjects highly predisposed to TMJ involvement, i.e. in patients with rheumatoid arthritis (RA). The aim of the study was to estimate the frequency of disturbances in the masticatory system of RA patients. In addition, the relationship between TMJ abnormalities and the signs and symptoms of dysfunction was investigated. The study consisted of sixty patients with RA and forty control subjects. Asymptomatic subjects were more frequent in the RA group than in the controls. Muscle pain during palpation was recorded in 53.3%, clicking in 53.3%, crepitation in 21.7%, reduced movement capacity of the TMJ in 41.7%, and restricted mouth opening in 31.7% of the RA patients examined. In the control group the most common symptoms and signs were clicking (57.5%), muscle pain during palpation (57.5%) and restricted opening (25.0%). Normal radiographic appearance of the TMJ in RA patients was found in 31.7%. Minor changes comprised 31.7%, moderate changes 21.6%, and severe changes or total loss of the condyle 15.0%. In the control group a normal joint was detected in 87.5%, while minor changes were encountered in 7.5%, and moderate or severe changes only in 5.0%. No relationship was found between Helkimo's anamnestic, clinical or occlusal indices and the severity of the disease graded according the criteria outlined by the American Rheumatism association (ARA). In the ARA group the frequency of signs and symptoms of dysfunction increased with the destructive changes in the TMJ area. In the controls, muscle pain during palpation and clicking sounds in the TMJ were most commonly connected with normal radiographic appearance of the TMJ. In the discriminant analysis the most discriminating factors were crepitation, tenderness to palpation of muscles and movement of TMJ.

Purification of adenovirus hexon protein by high-performance liquid chromatography

Adenovirus (Type 2)-infected HeLa cells were sonicated and treated with 1,1,2-trichlorotrifluoroethane. The water-soluble extract was ultracentrifuged and the supernatant, containing the dissociated proteins, was subjected to anion-exchange high-performance liquid chromatography on a Mono Q column in 50 mM bis-Tris-HCl (pH 6.5). Elution with a linear salt gradient resulted in a major peak, containing the hexon protein.

A study of haemostasis following the use of high doses of hydroxyethyl starch 120 and dextran in major laparotomies

The safety of plasma expanders, hydroxyethyl starch 120 and dextran 70, administered in the highest recommended doses (20 ml/kg) as adjuncts of component therapy of surgical blood loss was studied in patients undergoing major abdominal surgery and compared with a group receiving 4% albumin solution for initial haemodilution and whole blood for further blood loss replacement. Each group consisted of five patients in a relatively severe surgical, but good general condition including a normal haemostatic function and serum albumin level. The dilutional effect of the expanders on serum albumin and prothrombin-proconvertin level was observed during the day of operation. On the first postoperative day these values were equally low in all groups. Platelet count and bleeding time remained on a safe level throughout the study in all groups. Partial thromboplastic time values were unchanged. The factor VIII procoagulant (C), related antigen (R:Ag, vWF:Ag) and ristocetin cofactor levels, which were high preoperatively due to the underlying disease, remained at a safe level throughout the study. The increase in factor VIII related antigen associated with the hypercoagulable state induced by the surgical trauma was prevented by the plasma expanders. We conclude that dextran and hydroxyethyl starch can be used safely in a dose of 20 ml/kg in component therapy of surgical blood loss, provided that haematocrit is kept at an acceptable level, attention is paid to the postoperative hypoproteinaemia, and the patient has a normal haemostatic function preoperatively.

Quantitative vibratory perception thresholds of healthy and epileptic children

Quantitative vibratory perception threshold (VPT) measurements were performed on 102 healthy children and 79 children receiving anti-epileptic medication. Their ages ranged from three to 16. The VPTs correlated significantly with age and height. The rise in VPT with age may be associated with decreased receptor density. The level of mental alertness seemed to have no significant effect on vibratory perception. Only three of the children on anti-epileptics showed elevated VPTs. On the basis of this study, epileptic children seem to be free of the adverse effects of medication which occur later in adulthood. Children as young as three or four are quite capable of co-operating in this examination. The method can be recommended for use in follow-up studies of children and as a diagnostic aid when a disturbance of the sensory tract is suspected.

Vibratory perception threshold in patients with mild multiple sclerosis

The vibratory perception threshold (VPT) was measured bilaterally on both the upper and lower extremity in 69 patients with mild multiple sclerosis. In the case of the lower extremities the VPT measurements were closely correlated with qualitative vibratory perception measurements performed with a tuning fork; in the upper extremities the association was weak. The VPT was abnormal at least in one extremity in 38% of the patients. Quantitative VPT measurement seem to be a suitable technique for the detection of sensory symptoms of central origin.

Vibratory perception thresholds in shipyard workers exposed to solvents

Vibratory perception thresholds were determined for 90 subjects working at a shipyard with industrial solvents. The duration of exposure varied from 1 to 44 years (mean 19.6 years). Four of the men but none of women had bilaterally significantly increased thresholds in the lower limbs. In addition, seven subjects had increased thresholds in the upper extremities only. Fifteen subjects were further examined at a neurophysiological laboratory to determine the degree of possible peripheral polyneuropathy. The following measurements were made at the laboratory: motor and sensory conduction velocities, electromyography and heart rate variation during normal and forced breathing. The laboratory investigations revealed abnormalities in most of the subjects with increased vibratory perception thresholds in the lower limbs. On the other hand the laboratory measurements were normal for all subjects with increased thresholds in the upper limbs only. It is concluded that when peripheral polyneuropathy is suspected, quantitative vibratory perception threshold measurement is an easily applicable screening method for selecting subjects for further laboratory investigations.

Viral findings in children under the age of two years with expiratory difficulties

Viral findings were prospectively studied in lower respiratory tract infections in small children with and without expiratory difficulties. On first admission, a viral aetiology was found in 71 of 127 children (56%). On re-admission, a viral etiology was found in only two of 31 cases (6%). Respiratory syncytial viruses (RSV) were responsible for 71% of the cases with viral diagnoses. A recently-developed method for the direct detection of viral antigens in nasopharyngeal specimens by radio-immunoassay was more sensitive than complement fixation serology, especially in patients aged less than six months. Viral diagnosis was reached using this new method alone in 43% of infections caused by RSV and in 27% of infections caused by other viruses. In children under six months, RSV were found in 89% by direct antigen detection and in 22% by serology. We suggest that direct antigen detection should be used as the primary virological method in small children with lower respiratory tract infections. The aetiological agents were the same in cases with and without expiratory difficulties, RSV being found in about 40% of children in both instances. It is concluded that host factors are critical to the development of expiratory difficulties.

Assay of measles virus IgM and IgG class antibodies by use of peroxidase-labelled viral antigens

Purified measles virions, nucleocapsid protein and crude lysate of measles infected cells were labelled with horseradish peroxidase, and used for the detection of IgM and IgG antibodies to measles virus by direct enzyme immunoassay. The assays consisted of three layers: anti-human IgM or IgG immunoglobulins on solid-phase, test serum specimen and enzyme labelled viral antigen. For the expression of the results, a standard curve was included in each test and the O.D. values were changed to arbitrary antibody units. Specificity and sensitivity of the assays were compared with indirect EIAs. The specificity studies included a collection of serum specimens containing either rheumatoid factor, antinuclear antibodies or IgM antibody specific for other viruses. The assays proved both reliable and simple to perform and sensitivity was slightly higher than that for indirect EIAs. However, specificity was dependent on the purity of the viral antigens. When crude infected cell lysate antigen was used, some nonspecific results were obtained, particularly with serum specimens containing antinuclear antibodies. When virion or nucleocapsid protein were used, no nonspecific reactions were obtained.

Detection of low molecular weight cysteine proteinase inhibitors by time-resolved fluoroimmunoassay

A time-resolved fluoroimmunoassay was developed for the detection of 3 human low molecular weight cysteine proteinase inhibitors, ACPI (cystatin A), NCPI (cystatin B), and gamma-trace (cystatin C). Polystyrene tubes or polystyrene microtitration strips were used as solid phase. The rabbit anti-inhibitor immunoglobulins were used as the capture antibody, and, when labelled with europium, also as the detector antibody. The threshold sensitivity of the tests was 0.1 ng/ml for NCPI and 1 ng/ml for the others. All the 3 cysteine proteinase inhibitors, ACPI, NCPI, and gamma-trace, were detected in pooled serum samples of patients with kidney failure. gamma-Trace seemed to be quantitatively the major and ACPI the minor inhibitor. No other low molecular mass cysteine proteinase inhibitor was detected after isoelectric focusing of the 12 kDa area of gel filtered human serum.

Quantitative vibration perception thresholds in healthy subjects of working age

Quantitative determinations were made of vibration perception thresholds (VPTs) at six different measurement sites in 202 healthy subjects of working age (16-68 years). Measurements were made with a commercially available device, the frequency of vibrations being 100 Hz. The temperature of the skin at the measurement sites was also determined. The effect of temperature on VPT values was evaluated separately in eight test subjects. In addition, determinations were made of intraindividual variations in VPT values and it was found that there was an almost 100% variation under identical conditions. Variation in VPTs caused by temperature was only slightly greater than intraindividual variation from day to day. It did not seem to be necessary, for the making of measurements, to take into account variations of temperature within physiological limits. VPT was found to increase exponentially with age, more steeply among men than women. In practice, it is most important when making VPT measurements to take into account the age and sex of the subject and possibly also to allow for thresholds slightly higher than usual with subjects engaged in physical work. An important field of application for this method is in occupational health services, where there is a need for a simple and reliable screening test when attempting to diagnose polyneuropathy. The method is also very suitable for determining the neurotoxic effect of different drugs.

C reactive protein in the evaluation of febrile illness

We studied prospectively 154 febrile children to determine the diagnostic value of the quantitative serum C reactive protein concentrations (CRP). Children with acute otitis media, acute tonsillitis, or treated with antibiotics during the two previous weeks and infants less than 2 months of age were excluded. Ninety seven children were from private paediatric practice and 57 were patients who had been admitted to hospital. The comparison group consisted of 75 children with confirmed bacterial infections whose CRP values were recorded retrospectively. In the study group 35 (23%) children had a confirmed viral infection, 92 (59%) had a probable viral infection as judged from the clinical picture and outcome of the illness, and 27 (18%) had a bacterial or probable bacterial infection. When the duration of the disease was more than 12 hours and the CRP value less than 20 mg/l, all children had a confirmed or probable viral infection. Nine children (one from the study group and eight from the comparison group) were found to have a septic infection and a CRP value of 20 mg/l or less. In all these cases, however, the duration of the symptoms was less than 12 hours. In addition CRP less than or equal to 20 mg/l was found in five (14%) children with urinary tract infection in the comparison group. CRP values of 20-40 mg/l were recorded in children with both viral and bacterial infections. A CRP value greater than or equal to 40 mg/l detected 79% of bacterial infections with 90% specificity. Our data show that determination of serum CRP concentrations is a valuable tool in evaluating children who have been ill for more than 12 hours.

Synthesis of measles virus-specific IgM antibodies and IgM-class rheumatoid factor in relation to clinical onset of subacute sclerosing panencephalitis

Thirty-seven serum and 37 cerebrospinal fluid (CSF) specimens from 27 patients with subacute sclerosing panencephalitis (SSPE) were tested for measles virus (MV) IgM antibodies and IgM-class rheumatoid factor (RF) to determine if a temporal relationship exists between SSPE onset and these immunoglobulins. Sensitive solid-phase radioimmunoassays were used for immunoglobulin detection. Five of six MV IgM-positive CSF, both MV IgM-positive sera and six out of eight sera with elevated RF levels were collected within 1 yr of SSPE onset. Also collected during this time were six other sera having high binding in the MV IgM assay, which was not due to MV-specific IgM antibodies. Two of these sera had as high or higher binding of IgM to a Vero cell control antigen, suggesting involvement of an IgM-class autoantibody. The other four sera had false-positive MV IgM assay results due to RF interference. RF interference was dependent on both the titer and avidity of the MV IgG antibodies involved. Three conclusions can be drawn from these results. First, MV IgM antibodies and elevated RF levels are not markers for acute SSPE, despite the tendency for their synthesis at this stage of the disease. Second, immunoassay analysis of viral IgM antibodies must employ an appropriate control antigen to account for background IgM binding. Finally, even if RF levels are normal or near normal, a false-positive IgM immunoassay result can still occur if antigen-specific IgG antibodies in the same sample have the right combination of titer and avidity.

Myelin basic protein antibodies in catatonic schizophrenia

Myelin basic protein (MBP) antibodies were determined by solid-phase radioimmunoassay in the serum and cerebrospinal fluid of 10 patients with catatonia, 10 patients with other forms of schizophrenia, and 10 psychiatrically healthy controls. The mean counts per minute (cpm) value of serum anti-MBP antibody of the catatonia group was significantly higher than that of the patients with other forms of schizophrenic psychoses (p less than .05). No significant differences were observed among the cpm values of the CSF specimens from the three patient groups. The hypothesis of a central virus-induced immunologic aberration in catatonic schizophrenia is discussed.