Search PubMed⌕ Search

Biomedical subjects

R D Burk

Publications and source records attributed to R D Burk.

141 records · Page 8Linked to original sources
PubMed1984

Early manifestations of multiple sulfatase deficiency.

We describe two boys, presenting by 1 year of age, with developmental delay from birth, mildly coarse facial features, and hepatomegaly. These clinical features were most suggestive of a mucopolysaccharidosis, particularly MPS II. Biochemical studies, including sulfate incorporation in fibroblasts and lysosomal enzyme analyses in fibroblasts, leukocytes, and serum, showed abnormalities in both sulfatide and mucopolysaccharide metabolism and led to the diagnosis of multiple sulfatase deficiency. With time, both patients developed an ichthyotic rash and profound intellectual deterioration. We conclude that findings in the first year of life in some patients with MSD may closely resemble those in patients with a MPS disorder rather than the late infantile form of metachromatic leukodystrophy, as is classically described. Thus, MSD should be considered in the young patient suspected of having a MPS disorder.

Cerebroside-Sulfatase↗
PubMed1983

Use of repetitive DNA for diagnosis of chromosomal rearrangements.

We have used two repeated DNA fragments (3.4 and 2.1 kb) released from Y chromosome DNA by digestion with the restriction endonuclease Hae III to analyze potential Y chromosome/autosome translocations. Two female patients were studied who each had an abnormal chromosome 22 with extra quinacrine fluorescent material on the short arm. The origin of the 22p+ chromosomes was uncertain after standard cytologic examinations. Analysis of one patient's DNA with the Y-specific repeated DNA probes revealed the presence of both the 3.4 and 2.1kb Y-specific fragments. Thus, in this patient, the additional material was from the Y chromosome. Analysis of the second patient's DNA for Y-specific repeated DNA was negative, indicating that the extra chromosomal segment was not from the long arm of the Y chromosome. These two cases demonstrate that repeated DNA can distinguish between similar appearing aberrant chromosomes and may be useful in karyotypic and prenatal diagnosis.

Adult↗
PubMed1979

Regulation of expression of type C virion DNA polymerase (reverse transcriptase) in human x mouse and human x rat hybrid cells.

Human cells from 13 different individuals were fused to mouse and rat cells producing abundant type C viral particles. The results demonstrate that incorporation of active DNA polymerase (reverse transcriptase) into mature type C particles is suppressed in many of the hybrid clones but not in the parental mouse cell clones. This low particle-associated DNA polymerase phenotype was a heritable trait for over 100 cell generations but reversion to a high particle-associated DNA polymerase phenotype was possible. In contrast, no evidence for suppression of viral p30 antigen was found. These results suggest that human cells contain a factor(s) capable of interfering with the normal maturation of the mouse retrovirus DNA polymerase protein; however, it was not possible to assign this function to any of 20 different human chromosomes tested. It is suggested that these somatic cell hybrids may be useful in examining individual events in retrovirus packaging and release.

Animals↗
PubMed1976

Extinction of globin gene expression in human fibroblast x mouse erythroleukemia cell hybrids.

We have chosen human fibroblast x mouse erythroleukemia hybrid cells as a model system to examine regulation of unique genes. The globin genes were studied as a marker of erythroid differentiation. Three separate hybrid cell lines were incubated in 2% dimethylsulfoxide, an agent which induces erythroid differentiation of the parental erythroleukemia cells. Neither human nor mouse globin mRNA sequences could be detected by a sensitive molecular hybridization assay which utilized globin complementary D N A. However, td n a from one of the cell lines was shown to contain both the mouse and humand globin genes. Thus, loss of the genes by chromosomal segregation did not account for their failure to be expressed. Cocultivation of the mouse erythroleukemia cells with excess human fibroblasts did not prevent erythroid differentiation of the erythroleukemia cells in the presence of dimethylsulfoxide. Similarly globin gene expression was preserved in tetraploid cells generated by fusion of two erythroleukemia lines. Thus, extinction of globin geneated by fusion of two erythroleukemia lines. Thus, extinction of blobin gene expression in the human fibroblast x erythroleukemia hybrids occurred at the level of mRNA production and appeared to be due to the presence of the fibroblast genome within the hybrial cell.

Animals↗
PubMed1971

What is NRA?

Explore the source record for details and available documents.

Organizations↗
PubMedDate not supplied

Prevalence of human papillomavirus among STD clinic attenders in Jamaica: association of younger age and increased sexual activity.

BACKGROUND AND OBJECTIVES: Human papillomavirus is the major etiologic agent of cervical cancer. Although the incidence of cancer of the cervix is high in Jamaica, the prevalence of human papillomavirus among Jamaican women has not been defined. GOAL OF THE STUDY: To estimate the prevalence of human papillomavirus infection and associated risk factors in women attending an STD clinic in Kingston, Jamaica. STUDY DESIGN: A cross-sectional survey was done of 202 women attending an STD clinic in Kingston in 1990. Cervical and vaginal cells were collected by lavage, and human papillomavirus genomes were detected in extracted DNA using low-stringency Southern blot hybridization. RESULTS: Fifty-eight (28.7%) women were identified as HPV positive. Prevalence of HPV by age group was 39% in women 15-19 years old, 33% of women 20-24 years old, 31% in women 25-29 years old, and 17% in those 30 years or older. Increasing age was significantly associated with a lower prevalence of human papillomavirus infection (test for trend, P = 0.025). The effect of age was independent of years of sexual activity. Women reporting more than one sexual partner per month on average were found to have a significantly higher HPV prevalence (odds ratio 2.87, 95% confidence Interval 1.29-6.38), as were women who reported more frequent sex (test for trend, P = 0.006). CONCLUSIONS: Sexual behavior is associated with risk of human papillomavirus infection. The decrease of human papillomavirus prevalence in older women agrees with other studies that argue in favor of a biological effect, such as increased immunity to human papillomavirus with age. A better understanding of why immunity to human papillomavirus may develop in older women may provide the basis for developing an effective vaccine to prevent cancer of the cervix.

Adolescent↗
PubMedDate not supplied

Declining prevalence of cervicovaginal human papillomavirus infection with age is independent of other risk factors.

BACKGROUND AND OBJECTIVES: Human papillomavirus (HPV) infection of the female genital tract is the most common sexually transmitted disease. Although the prevalence of HPV in women without detectable cervical disease has been shown to decline with increasing age, the relationship to sexual behavior has not been investigated. GOAL: To identify risk factors for, and associated with the age-dependent decline in, genital HPV infection in women. STUDY DESIGN: The prevalence of HPV was determined in a cohort of 439 sexually active inner-city women between the ages of 18 and 50 years recruited in Brooklyn, New York. Cervicovaginal cells were collected by lavage, and HPV was detected by low-stringent Southern blot hybridization. RESULTS: The prevalence of HPV infection ranged from 36% in women younger than 25 years of age to 2.8% in women 45 years or older. Logistic regression analysis identified an increased risk for cervical HPV infection to be independently associated with number of sex partners in the past year (odds ratio [OR], 1.04 per yearly increase in age; 95% confidence interval [CI], 1.00 to 1.08), younger age (OR, 0.92 per year increase in age; 95% CI, 0.88 to 0.95), and not living with partner (OR, 2.28; 95% CI, 1.40 to 4.22). CONCLUSIONS: The lower prevalence of HPV infection in older women compared to younger women was found to be independent of sexual behavior. These results suggest that a biologic effect, such as HPV immunity acquired over time and with multiple exposures, may mediate the inverse relationship between age and HPV prevalence.

Adolescent↗
PubMedDate not supplied

Three value systems.

Explore the source record for details and available documents.

Attitude↗