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T Chonmaitree

Publications and source records attributed to T Chonmaitree.

At least 37 records · Page 2Linked to original sources
PubMed1995

Use of C-reactive protein in differentiation between acute bacterial and viral otitis media.

OBJECTIVES: The objectives of this investigation were: (1) to determine degree of elevation of serum C-reactive protein (CRP) in uncomplicated acute otitis media (AOM); (2) to compare serum CRP levels in bacterial and viral otitis media; and (3) to determine whether a single serum CRP level, obtained early in the course of AOM, could be used to differentiate between viral and bacterial otitis media. DESIGN AND METHODS: Sera were obtained from otherwise healthy infants and children with AOM who were 3 months to 7 years of age between 1989 and 1991. Tympanocentesis, bacterial and viral studies of the middle ear fluids, virologic studies of nasal wash specimens, measurements of serum antibody titers to respiratory viruses, blood counts, and quantitation of serum CRP concentrations were performed. After the initial tympanocentesis, an oral antibiotic was given for the next 10 days. The patients were clinically reevaluated over next 4 weeks. OUTCOME MEASURES: Serum CRP concentrations were compared among subjects with AOM who were divided into four groups based on the results of bacteriologic and virologic studies: group I, Bacterial infection (n = 82); group II, bacterial and viral infections (n = 69); group III, viral infection (n = 12); and group IV, no identifiable pathogen (n = 22). RESULTS: There was no statistical difference in serum CRP values among the four groups. The ranges of CRP were less than 0.6 to 22.8, less than 0.6 to 17.8, less than 0.6 to 2.0, and less than 0.6 to 6.8 mg/dL in groups I through IV, respectively. However, when CRP values in bacteria-positive cases were compared with CRP concentrations in bacteria-negative cases (1.58 +/- 3.16 vs 0.64 +/- 1.24 mg/dL), the difference was statistically significant. Furthermore, a significantly higher proportion of bacteria-positive cases had serum CRP concentrations greater than 2 mg/dL, compared with those in bacteria-negative cases. There was no correlation between initial CRP values and clinical findings and/or the clearance of bacteria from the middle ear. After 10 days of antibiotic treatment, CRP values returned to normal (< 0.6 mg/dL) in all cases. CONCLUSION: In AOM, the range of serum CRP varied from less than 0.6 to 22.8 mg/dL. High CRP values (> 2.0 mg/dL) were associated with 22% of cases of bacterial AOM but only with 6% of nonbacterial AOM. High levels of serum CRP were found to be very specific in detecting bacterial AOM, and no cases of viral AOM without a concurrent bacterial infection were found to exhibit high serum levels of CRP.

Acute Disease↗
PubMed1994

Antigenic diversity of respiratory syncytial virus subgroup B strains circulating during a community outbreak of infection.

The epidemiological characteristics and relationship between respiratory syncytial virus (RSV) subgroup and virulence during an outbreak of RSV infection occurring in Southeast Texas in the winter season 1991/92 are described. Fifty-two infants and children were diagnosed with RSV infection by rapid viral antigen detection and/or viral isolation. Subgrouping of the isolates was carried out using 11-monoclonal anti-bodies. Ten isolates were found to be subgroup B, and 8 isolates were subgroup A. The subgroup B strains showed 3 different patterns of reaction with monoclonal antibodies; one of these subgroups was examined further by restriction analysis of parts of its nucleocapsid and attachment protein genes. The peak of RSV outbreak was in December 1991. Both subtypes A and B circulated simultaneously in the same territory, and caused lower respiratory tract infections in similar proportions. The more frequent occurrence of the B subgroup and the diversity of its simultaneously circulated RSV strains have made this outbreak unusual.

Antigens, Viral↗
PubMed1994

Virus and bacteria enhance histamine production in middle ear fluids of children with acute otitis media.

Histamine levels were measured in 677 middle ear fluid (MEF) samples from 248 children (aged 2 months to 7 years) with acute otitis media (AOM); of these, 116 (47%) had documented viral infection. Histamine content was higher in bacteria-positive than in bacteria-negative MEF samples (P = .007) and higher in samples from patients with viral infection than in those from patients with no viral infection (P = .002). Bacteria and viruses together had an additive effect on histamine content in MEF. Histamine concentration in the initial MEF sample tended to be higher in patients with persistent otitis than in those with good response to treatment (P = .14). Results suggest that viruses, bacteria, or both induce histamine production, which leads to increased inflammation in the middle ear. Antihistaminic drugs may be beneficial. Large, prospective, controlled trials of the effects of antihistamine as an adjunct therapy in bacterial and viral AOM are required before recommendations can be made.

Acute Disease↗
PubMed1993

Association of rhinovirus infection with poor bacteriologic outcome of bacterial-viral otitis media.

Viruses--both alone and in combination with bacteria--have been shown to be a cause of acute otitis media (AOM). Moreover, the presence of virus in middle ear fluid (MEF) interferes with the bacteriologic response to antibiotic treatment in AOM. We studied various factors related to the eradication of bacteria from the MEF of infants and children who had AOM associated with a combination of bacteria and viruses. Of 622 cases of AOM diagnosed and treated between 1985 and 1991, 71 were due to such a combination. Bacteria were eradicated from MEF by 2-4 days of antibiotic treatment in 50 (70%) of these 71 cases; in the remaining 21 cases, the originally identified bacteria persisted or a new pathogenic bacterial species was detected after such treatment. These two groups of cases were compared with respect to the patients' age, sex, race, history of recurrent AOM, duration of respiratory symptoms, and compliance; the type of antibiotic treatment administered; the type of pathogenic bacteria and viruses identified in MEF; the presence of single or multiple pathogens; and the laterality of the disease. The only difference noted was in the type(s) of virus found in MEF. The presence of rhinovirus was associated with a higher rate of bacteriologic failure than was that of respiratory syncytial virus, parainfluenza virus, influenza virus, or other viruses. Our data suggest that the bacteriologic response to antibiotic treatment in bacterial-viral AOM may depend in part on the type(s) of virus present in MEF.

Anti-Bacterial Agents↗
PubMed1993

Effect of modulation of polymorphonuclear leukocyte migration with anti-CD18 antibody on pathogenesis of experimental otitis media in guinea pigs.

Guinea pigs were treated with anti-CD18 antibody (M8), and subsequently middle ears (ME) were infected with nontypeable Haemophilus influenzae. Forty-eight hours after infection, the ME washes of these animals had significantly lower polymorphonuclear leukocyte numbers but higher bacterial counts compared with washes of animals treated with control antibody (M11) or saline. The edema and epithelial damage of ME tissues correlated directly with polymorphonuclear leukocyte numbers and not bacterial counts.

Animals↗
PubMed1993

Rapid detection of poliovirus by reverse transcription and polymerase chain amplification: application for differentiation between poliovirus and nonpoliovirus enteroviruses.

This report describes a rapid method of detection of poliovirus from viral isolates of clinical specimens using a single set of primers selected from the conserved 5' noncoding region of the poliovirus genome. Of the 144 clinical viral isolates examined, 81 were positive for polioviruses and 50 were positive for nonpoliovirus enteroviruses by tissue culture neutralization and infectivity. All 81 (100%) of the viral isolates identified as poliovirus by tissue culture infectivity were also positive by polymerase chain reaction. Of 50 nonpoliovirus enterovirus isolates found to be negative for poliovirus by tissue culture neutralization and infectivity, 48 were also negative by polymerase chain reaction. The high sensitivity (100%) and specificity (96%) of the primer set indicate that this assay has potential clinical applicability in the diagnosis of nonpoliovirus enterovirus infection.

Base Sequence↗
PubMed1992

Effect of viral respiratory tract infection on outcome of acute otitis media.

We prospectively studied 271 infants and children (2 months to 7 years of age) with acute otitis media (AOM) for viral and bacterial causes, outcome at the end of therapy, and frequency of recurrence within 1 month. Comprehensive virologic methods, including viral antigen detection, cell culture, and serologic studies, were used to diagnose viral infection of the respiratory tract, middle ear, or both. Evidence of viral infection was found in 46% (124/271) of patients with AOM. Sixty-six patients (24%) had virus or viral antigen in the middle ear fluid; 50 of these patients (76%) also had bacteria in middle ear fluid, and 16 (24%) had virus alone. More patients with AOM and combined bacterial and viral infection (51%) had persistent otitis (3 to 12 days after institution of antibiotic treatment), compared with those with only bacterial otitis (35%; p = 0.05) or patients with only viral infection (19%; p less than 0.01). Of patients with only viral infection, 4 of 10 with virus in middle ear fluid had persistent otitis, compared with none of 11 patients who had virus only in nasal wash specimens or whose viral infection was diagnosed only by serologic studies. Our data suggest that viruses interact with bacteria and that concurrent viral infection can significantly worsen the clinical course of bacterial AOM. The presence of virus in middle ear fluid may contribute to the pathogenesis and outcome of bacterial AOM. The mechanism of these interactions deserve further investigation.

Amoxicillin↗
PubMed1992

Presence of cytomegalovirus and herpes simplex virus in middle ear fluids from children with acute otitis media.

Twenty-seven (10%) of 271 infants and children with acute otitis media (AOM) were found to be infected with cytomegalovirus (CMV) or herpes simplex virus type 1 (HSV). CMV or HSV, alone or in combination with bacteria or other viruses, was isolated from the middle ear fluid (MEF) of 10 patients. In three cases, CMV alone was isolated from the MEF, and in one case, HSV alone was isolated. One of the CMV cases involved an acute primary or reactivation of CMV infection, with CMV-bacterial otitis and conjunctivitis as major manifestations. One patient with AOM and stomatitis had purulent otitis associated with the presence of HSV in MEF, with no other bacterial or viral pathogens noted in MEF or nasal wash specimens. While most patients with CMV infection were probably asymptomatic excreters at the time of development of AOM, CMV did enter the middle ear. The presence of CMV in MEF was prolonged, and the patients continued to have clinical signs of otitis despite negative bacterial cultures. Among patients with bacterial otitis, a higher proportion of those who had CMV found only in nasal wash specimens had persistent bacteria in MEF, compared with those who were concurrently infected with other viruses (57% vs. 19%; P less than .04). This report is the first to suggest an etiologic role for CMV and HSV in AOM.

Acute Disease↗
PubMed1992

The changing spectrum of neonatal meningitis over a fifteen-year period.

One hundred seventy-seven cases of neonatal meningitis treated at the University of Texas Medical Branch at Galveston over a 15-year period (1974-1988) were reviewed. Over this period, the incidence of bacterial meningitis decreased, the incidence of aseptic meningitis remained stable, and the diagnosis of enteroviral meningitis increased in frequency. During 1984-1988, enterovirus was the most common cause of meningitis in neonates older than seven days and accounted for one third of all cases of neonatal meningitis. Half of all neonates with bacterial meningitis had negative blood cultures. We recommend that 1) diagnostic lumbar puncture remain part of the routine assessment of the neonate with suspected sepsis, and 2) CSF be cultured for enterovirus as well as for bacteria when a neonate older than seven days presents with suspected sepsis.

Age Factors↗
PubMed1991

Respiratory viruses induce production of histamine-releasing factor by mononuclear leukocytes: a possible role in the mechanism of virus-induced asthma.

Histamine-releasing factor (HRF) is a cytokine produced by mononuclear leukocytes when stimulated with antigens or mitogens. HRF is capable of inducing degranulation of basophils and release of histamine. To determine if respiratory viruses can induce HRF production, mononuclear leukocytes from healthy adult donors were exposed to influenza or respiratory syncytial virus in vitro. HRF activity was tested by culturing the supernatants with fresh peripheral blood leukocytes and measuring the percentage of histamine released. Significant enhancement in histamine release was found in both virus groups compared with that of media controls. Thus, mononuclear leukocytes from normal individuals produce HRF in response to exposure to respiratory viruses, suggesting that this cytokine, which causes basophil degranulation, may play a role in the mechanism of virus-induced bronchospasm.

Adult↗
PubMed1990

Respiratory viruses interfere with bacteriologic response to antibiotic in children with acute otitis media.

Fifty-eight infants and children with acute otitis media were prospectively studied for bacterial and viral pathogenesis and response to antibiotic therapy. Tympanocentesis for bacterial and viral cultures of middle ear fluids (MEF) was done before and 2-4 days after beginning treatment. Patients were followed until the end of antibiotic course. Bacteria were cultured from the preantibiotic MEF in 43 cases (74%). Viruses were cultured from the preantibiotic MEF in 11 cases (19%); all of these MEFs also contained bacterial pathogens. A significantly higher proportion of patients with both virus and bacteria (50%) failed to respond with clearing of bacteria 2-4 days into therapy compared with the group with bacteria alone (13%). The patients with persistently positive viral cultures of the MEF seemed to have purulent otitis of longer duration. Presence of virus in the MEF may interfere with bacteriologic and clinical responses to antibiotic. The mechanism of interference deserves further investigation.

Acute Disease↗
PubMed1989

Role of the virology laboratory in diagnosis and management of patients with central nervous system disease.

A number of viruses cause acute central nervous system disease. The two major clinical presentations are aseptic meningitis and the less common meningoencephalitis. Clinical virology laboratories are now more widely available than a decade ago; they can be operated on a modest scale and can be tailored to the needs of the patients they serve. Most laboratories can provide diagnostic information on diseases caused by enteroviruses, herpesviruses, and human immunodeficiency virus. Antiviral therapy for herpes simplex virus is now available. By providing a rapid diagnostic test or isolation of the virus or both, the virology laboratory plays a direct role in guiding antiviral therapy for patients with herpes simplex encephalitis. Although there is no specific drug available for enteroviruses, attention needs to be paid to these viruses since they are the most common cause of nonbacterial meningitis and the most common pathogens causing hospitalization for suspected sepsis in young infants in the United States during the warm months of the year. When the virology laboratory maximizes the speed of viral detection or isolation, it can make a significant impact on management of these patients. Early viral diagnosis benefits patients with enteroviral meningitis, most of whom are hospitalized and treated for bacterial sepsis or meningitis or both; these patients have the advantage of early withdrawal of antibiotics and intravenous therapy, early hospital discharge, and avoidance of the risks and costs of unnecessary tests and treatment. Enteroviral infection in young infants also is a risk factor for possible long-term sequelae. For compromised patients, the diagnostic information helps in selecting specific immunoglobulin therapy. Good communication between the physician and the laboratory will result in the most benefit to patients with central nervous system viral infection.

Clinical Laboratory Techniques↗
PubMed1988

Roentgenographic features of common pediatric viral respiratory tract infections.

Viral infections of the respiratory tract in infants and children are common. Little has been reported on roentgenographic findings associated with infection caused by common viruses other than with respiratory syncytial virus. We studied chest roentgenograms from 128 previously healthy infants and children who were infected with respiratory syncytial virus, parainfluenza virus, influenza virus, or adenovirus. Four common roentgenographic findings were detected: parahilar peribronchial infiltrates, hyperexpansion, segmental or lobar atelectasis, and hilar adenopathy. Diffuse interstitial infiltrates and significant pleural fluid accumulations rarely occurred in our series. We confirmed the popular but not well-documented belief that other common respiratory viruses can be associated with roentgenographic findings similar to those caused by respiratory syncytial virus. However, respiratory syncytial virus infection is associated with more abnormal chest roentgenograms than any of the other viruses regardless of the clinical syndrome. Hilar adenopathy was more common in adenovirus infection. Young infants had significantly more abnormal chest roentgenograms, with more hyperexpansion and parahilar peribronchial infiltration than older children. We also found a significant correlation between lobar atelectasis and severity of the illness. In infants and children with viral infection of the lower respiratory tract, roentgenographic information can be a useful adjunct to clinical viral diagnosis.

Adenoviridae Infections↗
PubMed1988

Role of interferon in leukocyte histamine release caused by common respiratory viruses.

Asthmatic attacks are often precipitated by viral respiratory infections. The mechanism of virus-induced asthma is still unclear. Interferon could be an important mediator in virus-induced hypersensitivity reactions, because interferon is induced by some respiratory viruses, and it can enhance IgE-mediated histamine release in vitro. We studied the effect of common respiratory viruses, including both interferon inducers and non-interferon inducers, on IgE-mediated leukocyte histamine release. Leukocytes from healthy, nonallergic donors were exposed to different strains of respiratory viruses, and basophils were challenged with antibody to IgE to release histamine. We found that the viruses are capable of enhancing IgE-mediated histamine release in the presence or absence of interferon. Our results suggest that although interferon may play a role in virus-induced hypersensivity reactions, other mechanisms probably also play a significant role.

Basophils↗
PubMed1988

Comparison of cell cultures for rapid isolation of enteroviruses.

Cell culture isolation is still the most reliable method for the detection of enteroviruses from clinical specimens. Rapid diagnosis of enterovirus infection affects patient management. To increase yield and enhance the rapidity of enterovirus isolation in cell cultures, we used Buffalo green monkey kidney (BGM) cells and subpassages of primary human embryonic kidney (HEK) cells in addition to the human diploid fibroblast (MRC-5) cells and primary cynomolgus or rhesus monkey kidney (MK) cells routinely used for enterovirus culturing. Growth characteristics of enteroviruses from 421 specimens were studied. All specimens were cultured in MRC-5, MK, and BGM cells, and 204 of these specimens were also cultured in HEK cells. Forty-two percent of the enteroviruses became positive within 3 days, and 85% did so within 7 days. MRC-5 cells provided the highest yield of enteroviruses overall and were the best cell type for the recovery of poliovirus and echovirus. MK cells provided the second best yield but were more useful than MRC-5 cells for coxsackievirus. BGM cells supported the growth of additional isolates of coxsackievirus and enhanced the speed of isolation. HEK cells supported the growth of additional isolates of both coxsackievirus and echovirus, but subculturing was always required for definite enterovirus cytopathic effects. The recovery rate increased 11% when two additional cell lines were used. The use of two tubes of MK cells significantly increased the yield of all enterovirus types. We conclude that the use of multiple appropriate cell lines increases yield and enhances the rapidity of enterovirus isolation.

Animals↗
PubMed1987

The importance of the virology laboratory in the diagnosis and management of viral meningitis.

Recent advances in cell culture techniques have made possible the rapid and accurate detection of enteroviruses, the most commonly identified cause of aseptic meningitis. Between 1983 and 1985, 69 patients were diagnosed as having enteroviral meningitis by viral culture of cerebrospinal fluid, throat swab, and/or rectal swab or stool specimens. Half of the 49 patients in whom the diagnosis was based on positive cerebrospinal fluid culture benefited directly from viral culture results by early withdrawal of antibiotics, early discharge, or changing of the diagnosis and prognosis of the disease. Enteroviral cultures became positive in as early as 24 hours, and most of the cultures became positive within one week. The cost of viral culture is comparable with that of other microbiologic tests. The virology laboratory has proved useful in the diagnosis and management of patients with enteroviral meningitis.

Adolescent↗