Biomedical subjects
Publications and source records attributed to J A Embil.
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The prevalence of antibodies to hepatitis A (anti-HA) was investigated in patients attending a clinic for haematological malignancies. Patients were divided into three age groups; the number with antibodies in each group was recorded. Of the 130 patients studied, 44% of those aged 4-26, 70% of those aged 27-50, and 83% of those aged 51-76, were positive. This study identifies patients attending a clinic for haematological malignancies (ie, patients with immunologic deficiencies) as a group of people having a high prevalence of anti-HA. In the oldest group (51-76), urban patients had a higher prevalence than rural patients - a pattern similar to that observed in elderly Red Cross blood donors in a previous study. Seroconversion was noted in six patients, three of whom seroconverted from anti-HA-negative to anti HA-positive within 12 months of the initial visit to the clinic.
Samples of serum from 421 patients attending a clinic for sexually transmitted diseases (STDs) were tested by radioimmunoassay for determination of the prevalence of antibodies to hepatitis A antigen (anti-HA). It was found that 42 . 4% of 33 homosexual men, 39 . 4% of 218 heterosexual men, and 38 . 8% of 170 female patients had positive results for anti-HA. The association between serological results and data on STD patients, using the variables of age, sexual type and preference, number of sexual partners in the preceding six months, and number of lifetime sexual partners and age, was determined statistically. The results show that the number of lifetime sexual partners is another factor concerned in the high prevalence of anti-HA.
Moose (Alces alces americana Clinton) blood collected by hunters during the 1977 and 1978 hunting seasons was tested for California group antibodies. Hemagglutination inhibition (HI) tests using snowshoe hare virus (SSH) as antigen yielded 37.02% HI-positive sera. Neutralization tests showed reactors reactors (67.5% positive) to SSH and classified six reactors as Jamestown Canyon virus (JC). This study reports the first finding of JC in a moose population; it also provides the first evidence of JC in Atlantic Canada and supports previous findings of SSH in Nova Scotia.
This study, the first of arbovirus activity in Prince Edward Island, has shown antibodies to the snowshoe hare strain of the California encephalitis group virus to be present in sera of wild and domestic animals; 15.35% of snowshoe hare, 20% of equine. and 2.5% of bovine sera were positive for hemagglutination inhibition antibody, confirmed by virus neutralization procedures.
The roles of Mycoplasma pneumoniae, M. hominis and Ureaplasma urealyticum in diseases of humans are currently under investigation. M. pneumoniae, which causes primary atypical pneumonia, is a well established pathogen of the respiratory tract. Complications of infection by this organism are also being recognized; they include disorders of the hematopoietic, cardiovascular, central nervous, musculoskeletal, cutaneous and gastrointestinal systems. The roles of the genital mycoplasmas M. hominis and U. urealyticum are controversial but may include infections of the genitourinary tract and in pregnancy as well as diseases of the newborn, such as neonatal pneumonia and meningitis. In this review atypical pneumonia due to M. pneumoniae is described and the role of mycoplasmas in other diseases is discussed.
A large number of North American equine samples were tested for the California group of arboviruses (CAL). Of 861 equine sera tested by hemagglutination inhibition using the snowshoe hare virus as an antigen, 106 (12.3%) were positive. Neutralization tests confirmed antibodies to this virus in 72 of the positive sera. This study provides evidence of CAL activity in the domestic animal population of Nova Scotia.
To evaluate the carrier rate of group B beta-hemolytic streptococci in males, we studied urethral swabs collected from 116 venereal disease (V.D.) clinic patients and 90 medical students. The prevalence rates for colonization in these groups were 8.6 and 2.2% respectively (statistically significant difference). The colonization rate in V.D. patients was higher in those with gonococcal infection than in those without but the difference was not statistically significant. Rates in patients with and without urethral symptoms were the same.
Placentas from a clinical study group of 446 high-risk pregnancies and 108 normal pregnancies were cultured for Mycoplasma hominis and Ureaplasma urealyticum and examined histologically. Results were compared and correlated with the clinical history. The recovery rate of U urealyticum, but not of M hominis, was significantly higher in the clinical study than in the control group. Isolation of both mycoplasmas was associated with polymorphonuclear leukocyte infiltration of placental membranes, fetal surface, and umbilical cord. Recovery of mycoplasma was significantly higher with prolonged membrane rupture, spontaneous abortion, stillbirth, and early neonatal death. Isolation of U urealyticum, but not of M hominis, was associated with prematurity, lower birth weight, and intrauterine growth retardation.
Antiserum against galactosyl(alpha 1 leads to 4)galactosyl(beta 1 leads to 4)glucosylceramide (globotriaosylceramide, Gb3) was raised in rabbits by the administration of four weekly intramuscular injections of 1.5 mg of the purified glycoplipid along with bovine serum albumin and Freund's complete adjuvant. AntiGb3 activity was quantitated initially by immunoprescipitation employing Gb3 mixed with 100-fold excess of lecithin and cholesterol (1 : 1 or 1 : 2, by wt.) as antigen. Subsequently, complement fixation tests done with antigen preparations containing Gb3/lecithin/cholesterol (1 :6 :20, by wt.) showed antiGb3 titres of up to 1 : 8192. Fractionation of the antiserum by BioGel A5m chromatography indicated the antibody was an IgM immunoglobulin. The partially purified antibody stimulated complement-dependent release of glucose from glucose-containing liposomes prepared with shingomyelin/cholesterol/dicetylphosphate/Gb3 (molar ratio, 100 : 75 :11 :1). The antibody crossreacted with the trisaccharide, Gal(alpha1 leads to 4)Gal(beta1 leads to 4)Glc, but not with galactosylerceramide, lactosylceramide, GM1 ganglioside, globotetraosylceramide, digalactosyldiglyceride or a number of low molecular weight saccharides.
Isolation rates of group B streptococci were determined for various sites in 100 women attending a Special Urology (VD) Clinic. Standard procedures were used for the collection of specimens, all of which were processed using a selective medium. Specimens from the urethra and lower vagina yielded significantly higher percentages of isolations than those collected from the cervix, upper vagina, and rectum. Although lower vaginal cultures yielded more positive results than urethral cultures, the difference was not significant.
In two cases of pneumonia associated with Chlamydia trachomatis in infants the symptoms began in the second week of life and the illness was severest at 4 weeks of age. Both infants were afebrile. One had a history of conjunctivitis. Both presented with a characteristic staccato cough and tachypnea but little evidence of peripheral airway obstruction. Chest roentgenograms showed interstitial and alveolar pulmonary infiltration in hyperexpanded lungs. The serum IgM concentrations were markedly elevated. C. trachomatis was cultured from specimens from both infants and one mother, and titres of antibody to the organism were substantially elevated in one infant and one mother.
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The carrier rate of group B beta-haemolytic streptococci (GBS) was assessed in pregnant and non-pregnant women attending four clinics. Multiple sites were sampled and standard methods were used to isolate GBS. Colonization rates were highest in patients attending a venereal disease clinic but were not associated with other sexually transmitted diseases. Higher colonization rates were detected when multiple sites were sampled. Serotypes II and III occurred most frequently.
101 pairs of human embryonic kidneys of 5-12 weeks' gestation were maintained in whole organ culture by our previously described technique, with herpesvirus hominis types1 and 2 added to our regular media. One kidney of each pair served as a control and was exposed to identical culture medium without virus. Cultures were maintained for 24-120 h to study the time sequence of viral infectivity. Organs were then examined for the presence of virus by electron microscopy and histochemical staining. Histological studies of virus-infected kidneys showed either (1) complete organ death or (2) virus localization in undifferentiated cells, plus disorganization of architecture in differentiated areas. Control organs showed normal organization.
An intramural population of 2480 neonates (88.7% of total births at the Grace Maternity Hospital, Halifax, Canada) was studied by rectal swabs collected within one hour after birth. Group B streptococci were recovered from 54 (21.7/1000 livebirths). Of these, 12(4.8/1000 livebirths) became symptomatic; all were term infants and none was born after prolonged membrane rupture. Two infants with pneumonia (0.8/1000) had severe life threatening illness; one was infected with group B streptococcus, serotype III, the other with both serotypes Ia and II. Serotyping of isolates showed equal distribution of types Ia, Ib, II and III but the symptomatic group showed a predominance of serotype III.
Serological study showed the presence of antibodies to snowshoe hare virus in 6--14% of snowshoe hares (Lepus americanus) samples in Nova Scotia. This report extends the known range of this virus in North America.