PubMed Health⌕ Search

Biomedical subjects

R Lesniewicz

Publications and source records attributed to R Lesniewicz.

5 recordsLinked to original sources
PubMed2001

Defects of type I procollagen metabolism correlated with decrease of prolidase activity in a case of lethal osteogenesis imperfecta.

We have studied the structure and metabolism of type I procollagen in a case of perinatal lethal osteogenesis imperfecta (OI) type II. Cultured skin fibroblasts from the proband synthesized both normal and abnormal forms of type I procollagen. Some abnormal, overmodified molecules were secreted by OI cells, although less efficiently than normal molecules from control cells. The OI fibroblasts accumulated large amounts of abnormal proalpha1(I) and proalpha2(I) chains intracellularly. The extracellular collagenolytic activity was decreased compared to control cells. Furthermore, OI cells produced less type I procollagen and demonstrated lower capacity to synthesize DNA than control cells. We have found that in contrast to prolinase activity, the activity of prolidase (an enzyme essential for collagen synthesis and cell growth) is also significantly reduced in OI cells. No differences were found in the amount of the enzyme protein recovered from both the OI and control cells. However, we found that expressions of beta1 integrin and insulin-like growth factor-I receptor (receptors known to play an important role in up regulation of prolidase activity) were decreased in OI cells compared to control cells. The decrease in prolidase activity may provide an important mechanism of altered cell growth and collagen metabolism involved in producing the perinatal lethal form of the OI phenotype.

Adult↗
PubMed1998

Three novel SRY mutations in XY gonadal dysgenesis and the enigma of XY gonadal dysgenesis cases without SRY mutations.

Mutations in the Y-located testis-determining gene SRY are one cause for XY sex reversal. We have previously identified four SRY mutations in a total of 45 sex-reversed females with XY gonadal dysgenesis (XY GD). In a new sample of 16 XY GD cases, three previously undescribed SRY mutations were identified. Two are point mutations that lead to amino acid substitutions in the HMG domain of SRY, M64R, and F67V. The third SRY mutation is a single base insertion 5' to the HMG box within codon 43, converting this lysine codon to a stop codon (K43X). A total of 33 SRY mutations have so far been described that account for only 10-15% of XY GD females. A further 10-15% of these cases result from deletion of SRY due to aberrant X/Y interchange. The etiology of the remaining 70-80% of XY GD cases is still enigmatic. Possible explanations for these XY sex-reversal cases are discussed.

Adolescent↗
PubMed1997

Changing trends in the diagnosis of endometriosis: a comparative study of women with pelvic endometriosis presenting with chronic pelvic pain or infertility.

OBJECTIVE: To compare demographic, epidemiologic, and medical data and to evaluate diagnostic trends in women with endometriosis and chronic pelvic pain symptoms or endometriosis and infertility. DESIGN: Retrospective analysis. SETTING: Institute for the Study and Treatment of Endometriosis. PATIENT(S): Six hundred ninety-three consecutive patients with endometriosis and chronic pelvic pain (n = 357) or endometriosis and infertility (n = 336). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Demographic and epidemiologic parameters, diagnostic trends. RESULT(S): Women with pelvic symptoms were younger, had less formal education, more frequent family history, and higher frequency and intensity of pelvic complaints. Mean ages at first symptom and diagnosis were lower in the pain group, but stage of endometriosis at first diagnosis was more advanced. The mean "diagnostic delay" was longer in the pelvic pain than in the infertile group (6.35 versus 3.13 years), but it decreased during three consecutive 5-year intervals in both groups, and there was also a gradual decrease in the frequency of advanced endometriosis at the time of first diagnosis. CONCLUSION(S): Demographic and epidemiologic parameters in women with endometriosis differ, depending whether chronic pelvic pain or infertility are the presenting symptoms. In the pain group, diagnostic delay is longer and endometriosis at diagnostic laparoscopy more advanced, indicating progressiveness of the disease. During the last 15 years, diagnostic delay steadily decreased and the frequency of advanced endometriosis at first diagnosis declined.

Adolescent↗
PubMed1992

Different risks in two familial translocations t(9;12) with similar breakpoints.

The risk of offspring with unbalanced karyotypes born to carriers of reciprocal chromosomal translocation (RCT) is important to evaluate for further family planning and prenatal diagnosis. The authors describe two families with carriers of similar RCT concerning breakpoint positions and discuss the different individual risks for abnormal progeny. These translocations were studied by GTG, RBG and CBG banding. They have the same breakpoint on 9p, i.e. 9p22, and a different one on 12p, i.e. terminal (pter----p13) and intermediate (p11.2), respectively. The risk value of 27% for family 1 was obtained directly from the large enough pedigree (high risk) a risk value of about 5% was estimated for family 2, according to the guidelines of Stene and Stengel-Rutkowski (1988). The data show that similar translocations with only slight differences in the breakpoints position have different risks for unbalanced progeny. Results of these empiric findings may be used directly in genetic counselling of a family with RCT leading to a single imbalance of the same segment.

Adolescent↗