Comparison of high-flow nasal cannula versus oxygen face mask for environmental bacterial contamination in critically ill pneumonia patients: a randomized controlled crossover trial.

Whereas high-flow nasal cannula use is gaining prevalence, its high gas flow raises concerns about aerosolization of infectious particles and spread of infection. This randomized controlled crossover non-inferiority trial (N = 20) evaluated the degree of environmental contamination by viable bacteria associated with the use of high-flow nasal cannula compared with conventional oxygen mask for critically ill patients with Gram-negative pneumonia. The results show that high-flow nasal cannula use was not associated with increased air or contact surface contamination by either Gram-negative bacteria or total bacteria, suggesting that additional infection control measures are not required.

Identification of actinomycete communities in Antarctic soil from Barrientos Island using PCR-denaturing gradient gel electrophoresis.

The diversity of specific bacteria taxa, such as the actinomycetes, has not been reported from the Antarctic island of Barrientos. The diversity of actinomycetes was estimated with two different strategies that use PCR-denaturing gradient gel electrophoresis. First, a PCR was applied, using a group-specific primer that allows selective amplification of actinomycete sequences. Second, a nested-PCR approach was used that allows the estimation of the relative abundance of actinomycetes within the bacterial community. Molecular identification, which was based on 16S rDNA sequence analysis, revealed eight genera of actinomycetes, Actinobacterium, Actinomyces, an uncultured Actinomycete, Streptomyces, Leifsonia, Frankineae, Rhodococcus, and Mycobacterium. The uncultured Actinomyces sp and Rhodococcus sp appear to be the prominent genera of actinomycetes in Barrientos Island soil. PCR-denaturing gradient gel electrophoresis patterns were used to look for correlations between actinomycete abundance and environmental characteristics, such as type of rookery and vegetation. There was a significant positive correlation between type of rookery and abundance of actinomycetes; soil samples collected from active chinstrap penguin rookeries had the highest actinomycete abundance. Vegetation type, such as moss, which could provide a microhabitat for bacteria, did not correlate significantly with actinomycete abundance.

Synchronous ipsilateral renal cell and transitional cell carcinoma.

The coexistence of multiple and synchronous primary neoplasms in the genitourinary system has only rarely been described in the literature. We present the case of a 78-year-old man with haematuria as the initial presentation, finally proven to be transitional cell carcinoma (TCC) combined with renal cell carcinoma (RCC). Intravenous urography (IVU), CT and arterial angiography studies revealed a space-occupying nodule at the right upper renal pelvicalyces showing mild enhancement with contrast medium. Another strong contrast medium enhancing exophytic tumour was found at the lower pole of kidney; there were hypodense foci and calcified components in this lesion. A right nephroureterectomy was performed. Pathological diagnosis was a papillary TCC and a clear cell type RCC. This is a rare case of combined renal malignancies diagnosed by imaging.

MR findings of penile lymphoma.

Penile lymphoma is extremely rare and secondary involvement of the penis by lymphoma may be due to retrograde spread or to direct extension from neighbouring organ. The appearance of penile lymphoma varies and can be mistaken for other soft tissue tumours. We report on a case with malignant lymphoma of the penis. MRI findings revealed soft-tissue mass of homogeneous isointensity around the middle to distal part of penis on T(1) weighted imaging and T(2) weighted imaging. It was well encapsulated, minimally enhanced and distinct from corpus cavernosum and corpus spongiosum.

Serodiagnosis of acute B hepatitis: comparison between a competitive binding radioimmunoassay and an enzyme linked immunosorbent assay for IgM antibody to hepatitis B core antigen.

The standard radioimmunoassay for anti-HBc (CORAB) was modified for the differential detection of anti-HBc IgM by incorporation of a step in which anti-HBc IgG was preferentially absorbed by Staphylococcus aureus cells (Protein A). The ratio (R) of anti-HBc IgM to total anti-HBc was evaluated by computing the ratio of sample cpm's after and before protein A absorption. The R values of acute B hepatitis ranged from 0.9 to 2.1 (mean 1.3 +/- 0.3) while those of chronic HBsAg carriers ranged from 3.1 to 8.3 (mean 4.9 +/- 1.1). Adopting 2.1 as the upper limit of R value for acute B infection, this modified CORAB was shown to have excellent correlation with enzyme immunoassay, and to be capable of differentiating acute from persistent HBV infection in HBsAg positive patients, and discriminating acute B hepatitis from non-A, non-B hepatitis in HBsAg negative but anti-HBc positive acute hepatitis.

Non-A, non-B hepatitis: a prospective study of a hemodialysis outbreak with evaluation of a serologic marker in patients and staff.

An outbreak of non-A, non-B hepatitis (NANBH) in a hemodialysis unit was prospectively studied and the clinical, biochemical, and serologic events were correlated with an experimental immunodiffusion assay for serum antigen and antibody. One hundred sixteen subjects (76 dialysis patients and 40 staff members) were studied over an 8-month period. Hepatitis was defined as two consecutive SGPT levels greater than two times the upper limit of normal occurring in two separate samples drawn greater than 7 days apart in the absence of other likely causes of liver disease. Weekly serum specimens were obtained and tested for SGPT, SGOT, alkaline phosphatase, bilirubin HBsAg, anti-HBc, anti-HBs, total anti-HAV, and anti-HAV IgM by commercial reagents, and for antigen and antibody by agar gel diffusion using reference reagents previously obtained from well-documented posttransfusion NANBH patients. Clinical evaluations were performed three times per week. Thirty patients and none of the staff developed NANBH. The NANBH patients were asymptomatic, except for two patients with jaundice. Fifteen of the 30 patients were positive for antigen which was detectable in at least one serum collected during the acute phase. Six patients and 10 staff without clinical NANBH or abnormal serology had antigen. Antigenemia was also observed in three patients with acute hepatitis B, with chronic hepatitis B in one patient and with alcoholic hepatitis in one patient. Thus, an antigen was detected in a high proportion of patients during the acute phase of NANBH, and it was also found in exposed patients who had other liver diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of acute hepatitis A by HAVAB-M, a direct radioimmunoassay for IgM anti-HAV.

A three-step solid-phase radioimmunoassay, HAVAB-M, was developed for use in clinical labs as an aid to diagnosing hepatitis A. Polystyrene beads were coated with anti-human IgM (mu-chain specific) and were incubated successively with serum specimen, HAV, and anti-HAV 125I. HAVAB-M was used to assay sera from patients with hepatitis A and was found to have high sensitivity for the IgM antibody to HAV. The antibody was detectable within a few days of onset of symptoms of hepatitis, and it reached maximum concentrations within one to three weeks. The test was designed so that most patients' sera would become negative approximately three months after onset. HAVAB-M was shown to be specific for IgM antibody, with virtually no detection of IgG anti-HAV. The test showed no interference fro rheumatoid factor and no cross-reactivity with sera from patients with hepatitis B or other infectious diseases.

Hepatitis B e-antigen and its correlation with other serological markers in chimpanzees.

Three chimpanzees experimentally infected with hepatitis B virus, and another three chimpanzees that were hepatitis surface antigen carriers, were studied for the presence of viral antigens and humoral immune responses. Quantitative analyses of hepatitis B surface and e-antigens in sequential serum samples at early acute stages revealed cyclic oscillations of these two antigens following a synchronous pattern. Similar analyses of anti-e-antigen and anti-hepatitis B core antigen antibodies from the three experimentally infected primates indicated that peak titers of these two antibodies occurred as surface antigen decreased to undetectable levels. Of the three surface-antigen carriers, two were positive for e-antigen and one was positive for e-antigen antibody for the entire course of surveillance (8, 9, and 22 months, respectively).

Serologic studies of transmission of hepatitis A in humans.

In 1968, studies of infectious hepatitis in volunteers were reported. Immunologic procedures for serologic study of the hepatitis A virus were not available at that time, and only the clinical and biochemical parameters of the disease were reported. Serial serum specimens from the participants in the study were retained; these specimens had been taken before inoculation and up to more than 100 days after inoculation. When a radioimmune assay for antibody to hepatitis A virus was developed, the series of sera was analyzed retrospectively. Forty-four male volunteers were involved in a series of three studies. Twenty (46%) of the volunteers were found to be initially immune to hepatitis A virus. Eighteen susceptible volunteers (with no preexisting antibody) were challenged with infectious virus. Eight of these volunteers developed clinical hepatitis and seroconverted; one seroconverted without evidence of clinical disease; and nine neither seroconverted nor had evidence of clinical disease. The radioimmune assay provided a method for diagnosis of immune status and of the acute disease caused by hepatitis A virus.

Viral hepatitis, type B. Studies on natural history and prevention re-examined.

Frozen serial serum specimens obtained from past studies on the natural history and prevention of Type B hepatitis in children were retested by radioimmunoassay for the following markers of hepatitis B infection: hepatitis B surface antigen (HBsAg) and antibody (anti-HBs), hepatitis B e antigen (HBeAg) and antibody (anti-HBe), and antibody to hepatitis B core antigen (anti-HBc). The interval between exposure and evidence of viremia (HBsAg) was as short as six days. HBsAg and HBeAg persisted for two to five months and occasionally for more than one year after recovery. After the disappearance of their respective antigens, anti-HBc and anti-HBs persisted for more than seven years and anti-HBe for one to two years. Treatment with hepatitis B immune globulin after exposure induced complete or partial protection or prolongation of the incubation period. Administration of heat-inactivated hepatitis B virus, MS-2 strain, to 29 children induced an inapparent infection in three, characterized by a transient appearance of HBsAg and HBeAg, and the persistence of anti-HBc, anti-HBe and anti-HBs for more than two years.

Cryptic association of e antigen with different morphologic forms of hepatitis B surface antigen.

When highly purified HBsAg particles, separated by rate zonal centrifugation into populations differing in predominant size, were tested for HBeAg, the e1 specificity was detected preferentially in association with particle fractions containing large filaments and Dane particles. These results were obtained both by agar gel diffusion and by radioimmunoassay for e antigen. The e antigen activity present in these fractions was potentiated by prior treatment of particles with Tween 80, suggesting cryptic localization of e1 specificity within or under the outer membrane. The HBeAg released by detergent treatment from a purified preparation composed predominantly of small-particle forms of HBsAg was separated by electrofocusing into a peak of nonparticulate e antigen in the pH range of 5.7--6.0. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed three major polypeptides in this preparation with approximate molecular weights of 25,000, 55,000, and 70,000. Furthermore, two additional peaks of e antigen activity were detected which migrated in association with HBsAg particles at isoelectric points of 4.4 and 5.5--5.6. The major portion of e antigen remained in association with particles after further purification by rate zonal centrifugation.

Prevalence of hepatitis B e antigen and its antibody as detected by radioimmunoassays.

A solid-phase radioimmunoassay (RIA) for the detection of hepatitis B e antigen (HBeAg) and antibody (anti-HBe) was developed. The RIA was approximately 1,000-fold more sensitive than rheophoresis for HBeAg, and approximately 6,000-fold more sensitive than rheophoresis for anti-HBe. Generally, less than one-fifth of hepatitis B antigen (HBsAg)-positive sera from blood donors were positive for either HBeAg or anti-HBe by rheophoresis; in contrast, more than 90% of the samples were positive by the RIA method. The ratio of HBeAg to anti-HBe among HBsAg carriers varied in different geographic localities. Also, the presence of HBeAg correlated directly with the titer of HBsAg and the presence of Dane core particles. Anti-HBe was associated with lower titers of serum HBsAg.

Detection of HBeAg and anti-HBe in acute hepatitis B by a sensitive radioimmunoassay.

A solid-phase radioimmunoassay using anti-HBe-coated polysterence beads and iodine-125-labeled anti-HBe of human origin was developed for the detection of HBeAg. Anti-HBe could be determined by a blocking test. Both assays were about 500-fold more sensitive than immunodiffusion. Few nonspecific positive results for HBeAg could be recognized in the anti-HBe test by increase in cpm over that of the negative control. HBeAg was not found in acute hepatitis A and non A-non B hepatitis or in a control group of accident patients. On admission to the hospital 12 of 48 (25%) acute hepatitis B patients from Greece and 17 of 20 (85%) acute hepatitis B patients from Germany were HBeAg-positive. All 39 initially HBeAg negative sera were already anti-HBe positive. Tests of the acute stage and follow-up sera of the 20 German patients indicated that HBeAg is regularly present in the incubation period and early acute phase of hepatitis B. After onset of disease the antigen is cleared from the serum very rapidly in uncomplicated cases and is usually followed by the appearance of anti-HBe. Like anti-HBc, anti-HBe can serve as a tool for the diagnosis of hepatitis B after the disappearance of HBsAg.

Seroepidemiological investigation of patients and family contacts in an epidemic of hepatitis A.

Serial blood and faecal samples were collected from patients and family contacts during an outbreak of hepatitis A in a village and tested by a solid-phase competitive type radioimmunoassay for hepatitis A antigen and hepatitis A antibody. The amount and duration of excretion of hepatitis A antigen was correlated with the severity of the illness. In 2 severe clinical cases, hepatitis A antigen was demonstrated in faecal extracts 11 days before the onset of jaundice and continuing for 10 days thereafter, with maximum shedding during the late incubation period. Faecal antigen was demonstrated in low concentrations for only 2 days in a patient with mild disease and in a person with subclinical infection. There was an inverse correlation between the incidence of infection and prevalence of hepatitis A antibody and age. Of 24 infections, 19 (79%) occurred in persons in the age group 0 to 20 years, a group in which only 6% of individuals had pre-existing antibody. Hepatitis A antibody was present in the serum of 3 persons in low titres of 1:20 to 1:40 on the day jaundice developed. The antibody titres increased very rapidly during the following 2 weeks of illness and slowly during the following months, reaching titres of 1:900 to 1:3500. In a separate study, a mean antibody titre of 1:591 was found in 13 patients, 12 years after clinical hepatitis A with jaundice.

Injection injury of the radial nerve.

Four cases of radial nerve palsy following intra-muscular injections into the arm are reported. Recovery occurred in all 4 cases--1 after neurolysis and 3 spontaneously. The mechanism of nerve damage and its treatment are discussed.

The influence of age on the results of open sternomastoid tenotomy in muscular torticollis.

The ideal age for surgery for muscular torticollis, the complications and results of open sternomastoid tenotomy were investigated in 60 patients operated on at different age-groups. Under the age of 1, tethering of the scar to the deeper structures was common and was mainly responsible for the lower percentage of good results (42.1 per cent). In the age-group 1 to 4 years, satisfactory correction of facial asymmetry, head and tilt and limitation of neck movements, was achieved with overall 66.7 per cent good results. However, in patients above the age of 5, not only was the correction of the secondary deformities uncertain but the late complications like loss of sternomastoid column, disfiguring scar and presence of lateral bands were more common. Only 33.3 per cent had good results in the 5 to 8 year age-group and none in the above 9 years age-group. The best time for surgery in muscular torticollis is in the patient between 1 and 4 years of age.

Comparison of confirmation methods for hepatitis-B antigen and the nature of false-positives detected by 125I-immunoglobulins.

Immunologic specificity associated with solid-phase direct radioimmunoassay (RIA) using guinea pig antibodies for HBsAg detection (Ausria-125TM) was examined further with physicochemical techniques. The RIA reactivities which could not be neutralized by wide-spectrum human anti-HBs serum appeared to be physically distinct from true HBsAg particles; hence, they were truly false-positive, resulting from immunologic cross-reactions. In order to ensure the full advantages of using this highly sensitive RIA test, a confirmatory test using specific human anti-HBs for neutralization is therefore required to distinguish the true- and false-positives. The basic RIA technique is a two-step procedure. Two basic confirmation procedures, namely, a first-step neutralization and a second-step neutralization, were investigated in depth to assess their efficacy and practicality for confirmation. Both procedures were effective for confirmation purposes; however, the first-step neutralization procedure failed to confirm some high-titered HBsAg samples unless these samples were appropriately diluted. The second-step neutralization method did not require dilutions of any test samples.