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Biomedical subjects

J S Friedman

Publications and source records attributed to J S Friedman.

13 recordsLinked to original sources
PubMed2001

Absence of mitochondrial superoxide dismutase results in a murine hemolytic anemia responsive to therapy with a catalytic antioxidant.

Manganese superoxide dismutase 2 (SOD2) is a critical component of the mitochondrial pathway for detoxification of O2(-), and targeted disruption of this locus leads to embryonic or neonatal lethality in mice. To follow the effects of SOD2 deficiency in cells over a longer time course, we created hematopoietic chimeras in which all blood cells are derived from fetal liver stem cells of Sod2 knockout, heterozygous, or wild-type littermates. Stem cells of each genotype efficiently rescued hematopoiesis and allowed long-term survival of lethally irradiated host animals. Peripheral blood analysis of leukocyte populations revealed no differences in reconstitution kinetics of T cells, B cells, or myeloid cells when comparing Sod2(+/+), Sod2(-/-), and Sod2(+/-) fetal liver recipients. However, animals receiving Sod2(-/-) cells were persistently anemic, with findings suggestive of a hemolytic process. Loss of SOD2 in erythroid progenitor cells results in enhanced protein oxidative damage, altered membrane deformation, and reduced survival of red cells. Treatment of anemic animals with Euk-8, a catalytic antioxidant with both SOD and catalase activities, significantly corrected this oxidative stress-induced condition. Such therapy may prove useful in treatment of human disorders such as sideroblastic anemia, which SOD2 deficiency most closely resembles.

Anemia, Hemolytic↗
PubMed2001

Isolation of a ubiquitin-like (UBL5) gene from a screen identifying highly expressed and conserved iris genes.

We have screened a human adult iris cDNA library to identify genes that are highly expressed and conserved between humans and pigs. We identified human iris cDNAs that hybridized at high stringency to a porcine choroidal ring cDNA probe. Of 1568 human iris cDNAs examined, 176 were found to have high expression in porcine choroidal rings. One of the 176 clones was identified as a previously uncharacterized cDNA that we have named the Ubiquitin-like 5 gene (UBL5). The UBL5 gene is located on chromosome 19p13.2, and its genomic structure has been examined. There is a UBL5 pseudogene on chromosome 17p11.2. We have also found homologues to the UBL5 gene in Arabidopsis thaliana, Caenorhabditis elegans, Schizosaccharomyces pombe, and Saccharomyces cerevisiae. Northern blot analysis of the Ubiquitin-like gene 5 revealed expression in every tissue tested, with the highest levels of RNA expression in heart, skeletal muscle, kidney, liver, iris, and lymphoblasts. Intracellular localization experiments in COS-7 cells showed that the recombinant UBL5 protein is cytoplasmic. Western analysis demonstrated that the recombinant UBL5 protein is approximately 9 kDa, as predicted from the cDNA. A comparison between UBL5 and its homologues with other Ubiquitin-like proteins and Ubiquitin, using the PROTDIST program, suggests that the UBL5 genes are a separate class of Ubiquitin-like genes. Further characterization of the UBL5 gene will determine the function of the encoded protein and whether it is a candidate for ocular disease.

Adult↗
PubMed2000

Isolation of a novel iris-specific and leucine-rich repeat protein (oculoglycan) using differential selection.

PURPOSE: To identify and characterize genes expressed in the iris. METHODS: A human adult iris cDNA library was constructed and subjected to a differential selection screen to identify genes preferentially expressed in iris or trabecular tissue versus those expressed in lymphoblasts. Selected cDNAs were partially sequenced. Novel cDNAs were chosen for further analysis. The cDNAs were localized within chromosomes using a radiation hybrid (RH) mapping panel. The tissue expression profile of each cDNA was found through computer-based searches. One novel cDNA was subjected to 5' rapid amplification of cDNA ends and Northern blot analysis. RESULTS: Of 24 differentially selected clones, 14 cDNAs had homology to known genes, whereas the other 10 were previously uncharacterized cDNA clones. IR185 was one novel iris cDNA identified. Northern blot analysis with IR185 indicated that it is expressed in human fetal liver as a 2.7-kb transcript and in adult iris as a 1.6-kb transcript. Computer-based searches of public databases and reverse transcription-polymerase chain reaction experiments have determined that IR185 is also expressed in retina. RH mapping experiments have localized IR185 to the chromosomal interval 1q31-q32, near the loci for age-related degeneration (1q25-q31) and retinitis pigmentosa 12 (1q31-q32), and IR185 is in the region for posterior column ataxia with retinitis pigmentosa (1q31-q32). It has a 996-bp open reading frame encoding a putative protein with homology to the small leucine-rich proteoglycan (SLRP) family. The IR185 gene has been tentatively named oculoglycan. CONCLUSIONS: Differential selection is a technique that has been useful in identifying genes specific to a variety of tissues. This is the first time this technique has been applied to the iris. Characterizing genes highly or uniquely expressed in the iris can assist in clarifying our understanding of iris function and lead to a better understanding of the molecular pathogenesis of ocular disease. IR185 is a tentative candidate for one eye disorder genetically localized to chromosome 1q31-q32.

Amino Acid Sequence↗
PubMed1998

Chromosomal localization and genomic organization of the human retinal rod Na-Ca+K exchanger.

The retinal rod Na-Ca+K exchanger is a unique calcium extrusion protein found only in the outer segments of retinal rod photoreceptors. Rod Na-Ca+K exchanger cDNA (NCKX1) has been cloned from bovine and human retinas. Here, we have used fluorescent in situ hybridization and radiation hybrid mapping to localize the human NCKX1 gene to chromosome 15q22. We have determined the genomic organization of human rod NCKX1 and found one intron in the 5' untranslated region and eight introns within the coding region.

Amino Acid Sequence↗
PubMed1982

Defining legitimate births in Fulton County, Georgia, 1977.

In 1977, the parents of 1,043 births recorded for 15 to 19 year old women in Fulton County, Georgia, were classified as married. However, only 36 per cent of these births could be linked with marriage certificates. An analysis of the unlinked birth certificates showed that the overwhelming majority of teenage parents did not appear to be legally married. The absence of a specific statement regarding marital status on birth certificates results in inaccuracies in the reporting of births according to marital status of parents.

Adolescent↗
PubMed1975

Sexuality in later life.

Aging produces changes in sexual organs, in the strength of the secual urge, and in physiologic responses and psychologic tensions. While sexual interest ans sexual thought decline, they do not disappear. Availability of partners and retention of youthful attitudes are important elements of sexual interest and activity at older ages. All authorities seem to agree that regularity of sexual activity is the essential factor in maintaining sexual capacity and performances for both males and females. Older persons who are sexually inactive and comfortable with that adjustment should not be made to feel inadequate, but those who are struggling with sexual problems should be helped to overcome them. Nurses should be prepared to take an active role in sexual conseling of the elderly and in agitating for social, political, legal, and attitudinal change.

Adolescent↗
PubMedDate not supplied

Assessing the reproductive behavior of on- and off-reservation American Indian females: characteristics of two groups in Montana.

Only limited fertility and general reproductive health data exist on American Indians. Using data from the 1987 Montana American Indian Health Risk Assessment, we found that the fertility of American Indians in Great Falls and on the Blackfeet Reservation was similar to blacks in the U.S. and relatively high when compared with fertility of whites in the United States. The influence of the direct determinants of fertility (nuptiality, contraceptive use, and lactation) was very different for the populations examined in this study. Great Falls American Indians and the U.S. black population were similar regarding age at first sexual intercourse (very young), breastfeeding (low prevalence and short duration), planning status of pregnancies (high unplanned), and contraceptive use (only moderate use). In contrast, Blackfeet women on the reservation and the U.S. white population married relatively late, had very high contraceptive use, used effective methods of contraception, and had moderately high levels of breastfeeding. However, Blackfeet fertility was much higher than that of whites. Three interrelated reasons are suggested as possible explanations. Blackfeet couples either wanted high fertility, were relatively poor users of family planning methods, or used less effective methods until they had exceeded their desired family size after which time they turned to sterilization. These finds raise numerous questions concerning the social and economic factors that may account for these group similarities and differences. Further studies with much larger data sets are needed to address these issues adequately.

Adolescent↗
PubMedDate not supplied

Prevalence of behavioral risk factors in two American Indian populations in Montana.

Despite great improvements in recent decades, the health status of American Indians continues to lag behind that of other Americans. Continued health improvement will depend largely on changes in individual behavior. However, few data exist on health risk behaviors among American Indians. We used face-to-face interviews to estimate the prevalence of some of these behaviors among American Indians 15-49 years of age in two Montana locations: on the Blackfeet Reservation and in Great Falls. The prevalence of several important health risk behaviors was higher in these populations than in adult Montana residents in general. Tobacco use was very prevalent. Fifty percent of on-reservation women, 62% of off-reservation women, 34% of on-reservation men, and 63% of off-reservation men were smokers at the time of the survey. Thirty-three percent of reservation men used smokeless tobacco. Other risk behaviors of high prevalence included acute heavy drinking (26% to 42% of men); overweight (29% to 41% of females); sedentary lifestyle (46% to 62% of all respondents); and nonuse of seat belts (64% to 79% of all respondents). Tribal leaders and the Indian Health Service are using the survey results to reduce the prevalence of behaviors harming the health of Indian people. In addition to providing valuable information about the surveyed populations, the survey served as a pilot for subsequent surveys of other American Indian groups.

Adolescent↗