PubMed HealthSearch

Biomedical subjects

J Joncas

Publications and source records attributed to J Joncas.

At least 19 recordsLinked to original sources

Natural history of muscle weakness in Friedreich's Ataxia and its relation to loss of ambulation.

From 1979 to 1992, 170 muscular assessments performed on 33 patients with Friedreich's Ataxia were reviewed. The average followup was 6 years. All muscle evaluations were done by the same team. It was possible to delineate a fairly regular and statistically significant pattern of slowly progressive and symmetrical loss of strength affecting mainly the lower limbs, and more specifically the pelvic girdle muscles. The first significant weakness was observed in the hip extensor group, followed in a variable fashion by other muscle groups of the lower limb. Upper limb and trunk muscles remained relatively spared until late in the disease process, with an overall strength approximately 80% of normal. Use of a wheelchair began at a mean age of 18.2 years, at which time the lower-limb strength averaged 70% of normal. Patients became totally unable to walk at a mean of age 20.5 years old, with a further decline in lower limb strength to 56% of normal. Weakness does not appear to be the primary cause for loss of ambulation in patients with Friedreich's ataxia.

Adolescent

Lack of scientific evidence for the treatment of lateral epicondylitis of the elbow. An attempted meta-analysis.

We have reviewed 185 articles published since 1966 to assess the scientific evidence for methods of treatment for lateral epicondylitis of the elbow. Of the 185 articles, 78 discussed treatment, but since the natural history of the syndrome is uncertain we considered only those series with concurrent control groups. Only 18 of these were randomised and controlled studies. We then graded these papers for scientific validity, using the methods of Chalmers et al (1981). The mean score of the 18 articles was only 33%, with a range from 6% to 73%. A minimum of 70% is required for a valid clinical trial, and we therefore concluded that there was insufficient scientific evidence to support any of the current methods of treatment. There were too many methodological differences to allow a quantitative meta-analysis, but our qualitative review established the importance of the natural evolution of the syndrome and of the placebo effect of all treatments. Properly designed, controlled trials are needed.

Acute Disease

Lack of effect of peroral acyclovir for the treatment of acute infectious mononucleosis.

Perorally administered acyclovir was evaluated in the therapy of acute infectious mononucleosis in a multicentered, randomized, double-blind, placebo-controlled trial. A total of 120 patients received 600 mg of acyclovir or placebo five times daily for 10 days. All patients were entered into the study within 7 days of symptom onset and had a positive Monospot test. Analysis of mean values and time to resolution of fever, lymphadenopathy, weight change, hepatomegaly, splenomegaly, liver function tests, atypical lymphocytes, hours of bed rest, sense of well-being, and return to normal activities revealed no significant differences. There was a trend toward suppression of Epstein-Barr virus excretion in the oropharynx in acyclovir recipients. No toxicity was detected in patients treated with acyclovir. Under the conditions of the study, there was no evidence that treatment with perorally administered acyclovir affected the course of infectious mononucleosis.

Acyclovir

Brief report: killer cell defect and persistent immunological abnormalities in two patients with chronic active Epstein-Barr virus infection.

Two members of a family have manifested a syndrome of chronic active Epstein-Barr virus (EBV) infection. A father and his daughter suffered prolonged or recurrent mononucleosis, with splenomegaly, anemia, and intermittent fever; persistent immunological abnormalities included defective natural killer (NK) cytotoxicity, inverted CD4/CD8 ratios, hyper IgG1, high EBV viral capsid antigen (VCA) and early antigen (EA) antibodies, and low or undetectable EBV nuclear antigen (EBNA) antibody titers. The EBV seronegative member of the family was free of these abnormalities. However, NK activity in the seronegative individual was low-normal and its EBV-specific antibody-dependent K-cell cytotoxicity (EBV-ADCC) was abnormally low, suggesting that this K-NK cell defect may be primary. The father, who suffered from the syndrome for more than 15 years, lacked (or lost) antibodies to EBV-envelope and infected cell membranes, such as antibody-dependent cellular cytotoxicity (ADCC), neutralizing (NT), and gp 350/220 antibodies. Slow improvement over a period of years was heralded by rising NK cytotoxicity.

Adolescent

Epstein-Barr virus related lymphoepithelioma-like carcinoma of lung.

A malignant neoplasm localized to the lung is reported in a rather unusual host: a 40-year-old female, nonsmoker, of South-East Asiatic origin. The histology was of nasopharyngeal-like carcinoma character and ultrastructural examination confirmed a diagnosis of nonkeratinizing, poorly differentiated squamous cell carcinoma. The clinicopathologic findings were more suggestive of a primary pulmonary origin than the manifestation of an occult nasopharyngeal primary. The immunological profile was highly suggestive of an Epstein-Barr virus (EBV) associated epithelial neoplasia. This case might widen the spectrum of EBV-associated neoplasia, by inclusion of lower respiratory tract as a target organ.

Adult

Epstein-Barr virus infection in the neonatal period and in childhood.

In an attempt to detect and characterize congenital, neonatal and early childhood EBV infections, a prospective sero-epidemiological study was undertaken in 112 newborn infants and their mothers, 25 additional newborns undergoing exchange transfusion, 114 randomly selected hospitalized infants aged 0 to 3 years, and 109 siblings and parents of these infants. Leukocyte culture was attempted in all the newborns and in 25 pre- and post-transfusion.The findings of EBV seroconversion in six patients without clearly apparent illness, infectious mononucleosis in only one case with significant EBV antibody rise, seroreversion in three cases in early childhood, higher newborn than maternal EBV antibody titres in three cases and the establishment of two permanent lymphoblastoid cell lines from newborns following exchange transfusion raise the possibility of abortive primary EBV infection in early life. Congenital or neonatal infections following exchange transfusions, however, could not be substantiated with certainty since the EBV antibodies did not persist at follow-up except possibly in two cases. Parenteral transmission of the EB virus by exchange transfusion at birth is probably prevented by the presence of EBV antibodies in either donor or recipient.

Antibodies, Viral

Serological response of the EBV antibodies in pediatric cases of infectious mononucleosis and in their contacts.

The EBV antibodies were measured in 378 sera from a group of 129 pediatric and older cases of infectious mononucleosis and from 117 family and social contacts. Cases of infectious mononucleosis with only one exception were EBV seropositive in acute and/or convalescent sera. Fourteen cases, however, from whom no convalescent serum was available were EBV seronegative. A rise in EBV antibodies of two dilutions or more was demonstrated in 15 of the 129 cases. The prevalence of these antibodies in contacts reached 50 to 70% in each of four age groups. A significant antibody rise was encountered in only four cases, one of whom was found to have infectious mononucleosis simultaneously with the index case and one after an interdisease period of 10 months. The infectivity of the EB virus (and of infectious mononucleosis if causally related) and its horizontal transmission seem to be as low in nature as they appear to be experimentally in the laboratory.

Adolescent