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Biomedical subjects

W Parks

Publications and source records attributed to W Parks.

At least 19 recordsLinked to original sources
PubMed2005

Unequal treatment access and malaria risk in a community-based intervention program in the Philippines.

This study assesses the influence of several malaria risk factors and volunteer health worker (VHW) accessibility on parasite prevalence and treatment-seeking in a remote area of Mindanao, the Philippines. An anti-malaria program in the area seeks to devolve malaria diagnosis and treatment to the VHWs. Firstly, the relationship between malaria and demographic factors, bednet use, and access to treatment was investigated. Secondly, adults from villages with and without resident VHWs were questioned on historical and proposed treatment-seeking for fever and the capacity of the communities to support more health workers was assessed. Parasite prevalence was significantly higher among patients living in villages lacking a resident VHW (adjusted OR=3.88, p=0.02), where proposed delays in consulting VHWs and the official health service, and the use of alternative medicine, were also significantly higher. Kinship or social closeness to VHWs appears to play a role in accessibility. The educational and economic requirements demanded of VHWs impede potential expansion of the program to non-serviced villages. If the effectiveness and equity of community-based treatment strategies is to be increased, increased flexibility allowing use of local, less-educated, drug dispensers needs to be considered.

Adolescent↗
PubMed2001

Gender, mosquitos and malaria: implications for community development programs in Laputta, Myanmar.

This paper examines the gender roles linked to division of labor and potential exposure to mosquitos and malaria prevention activities. A "Human Development Initiative" (HDI) Project has been launched in Laputta, a mangrove delta region of Myanmar assisted by United Nations Development Program since 1994. The project aims to improve rural community access to primary health care and provide micro-credit programs, income generation schemes, and educational opportunities as a basis for community empowerment. Women and children of low-income households are the target beneficiaries. Prior to self-care training program and distribution of self-care manuals, altogether 20 focus group discussions (separately assigned to men and women) were conducted in eight study villages between January to February 2000. The primary vector for malaria in study area is Anopheles sundaicus. Rural women were prone to malaria due to exposure to mosquitos within the peak biting period at night because of their gender assigned roles. Both men and women perceived that mosquitos commonly bite before midnight, more at dusk. Lack of awareness of correlation between mosquitos and malaria together with lack of affordability enhance either non-use or shared use of bed-nets at home. Rural women did not consider destruction of breeding places of mosquitos as their major concern. Thus, it is essential for program planners to motivate local women for more active participation in vector control measures within and beyond their households in the context of community development programs.

Animals↗
PubMed2000

Five human genes encoding F-box proteins: chromosome mapping and analysis in human tumors.

Members of the F-box protein (Fbp) family are characterized by an approximately 40 amino acid F-box motif. SCF complexes (formed by Skp1, cullin, and one of many Fbps) act as protein-ubiquitin ligases that control the G(1)/S transition of the eukaryotic cell cycle. The substrate specificity of SCF complexes is determined by the presence of different Fbp subunits that recruit specific substrates for ubiquitination. Unchecked degradation of cellular regulatory proteins has been observed in certain tumors and it is possible that deregulated ubiquitin ligases play a role in the altered degradation of cell cycle regulators. We have recently identified a family of human Fbps. As a first step aimed at determining if FBP genes could be involved in human neoplasia, we have mapped the chromosome positions of 5 FBP genes by fluorescence in situ hybridization (FISH) to 10q24 (BTRC alias beta-TRCP/FBW1a), 9q34 (FBXW2 alias FBW2), 13q22 (FBXL3A alias FBL3a), 5p12 (FBXO4 alias FBX4) and 6q25-->q26 (FBXO5 alias FBX5). Since most of these are chromosomal loci frequently altered in tumors, we have screened 42 human tumor cell lines and 48 human tumor samples by Southern hybridization and FISH. While no gross alterations of the genes encoding beta-Trcp/Fbw1a, Fbw2, Fbx4 and Fbx5 were found, heterozygous deletion of the FBXL3A gene was found in four of 13 small cell carcinoma cell lines. This is the first evaluation of genes encoding Fbps in human tumors.

Amino Acid Motifs↗
PubMed1999

Identification of a family of human F-box proteins.

F-box proteins are an expanding family of eukaryotic proteins characterized by an approximately 40 aminoacid motif, the F box (so named because cyclin F was one of the first proteins in which this motif was identified) [1]. Some F-box proteins have been shown to be critical for the controlled degradation of cellular regulatory proteins [2] [3]. In fact, F-box proteins are one of the four subunits of ubiquitin protein ligases called SCFs. The other three subunits are the Skp1 protein; one of the cullin proteins (Cul1 in metazoans and Cdc53 or Cul A in the yeast Saccharomyces cerevisiae); and the recently identified Roc1 protein (also called Rbx1 or Hrt1). SCF ligases bring ubiquitin conjugating enzymes (either Ubc3 or Ubc4) to substrates that are specifically recruited by the different F-box proteins. The need for high substrate specificity and the large number of known F-box proteins in yeast and worms [2] [4] suggest the existence of a large family of mammalian F-box proteins. Using Skp1 as a bait in a yeast two-hybrid screen and by searching DNA databases, we identified a family of 26 human F-box proteins, 25 of which were novel. Some of these proteins contained WD-40 domains or leucine-rich repeats; others contained either different protein-protein interaction modules or no recognizable motifs. We have named the F-box proteins that contain WD-40 domains Fbws, those containing leucine-rich repeats, Fbls, and the remaining ones Fbxs. We have further characterized representative members of these three classes of F-box proteins.

Amino Acid Motifs↗
PubMed1999

The use of the Naugle orbitometer in maxillofacial trauma.

BACKGROUND AND OBJECTIVES: Objective measuring of globe position is not a universal practice in the management of orbital trauma. Few studies in the literature advocate its routine use. METHODS AND MATERIALS: The Hertel exophthalmometer is the most widely used instrument; however, in trauma involving the lateral orbital rim (e.g., in zygoma fractures), the results are inaccurate because the displacement of the zygomatic bone interferes with its reference point on the lateral orbital rim. A more recent measuring device, the Naugle orbitometer, was introduced in 1992. It uses the superior orbital rim (frontal bar) and inferior orbital rim (malar eminence) as reference points. RESULTS AND/OR CONCLUSIONS: This article reports experience with this instrument in objective measuring the position of the globe in orbital trauma. These measurements are used 1) to monitor fractures that may not require repair but should be followed and observed for dystopia or enophthalmos, 2) to determine the adequacy of fracture repair, and 3) to determine the volume adjustment required for correcting enophthalmos. Future studies will be directed to compare the accuracy of Naugle and Hertel exophthalmometers.

Adult↗
PubMed1998

Development of endometriosis from embryonic duct remnants.

Among 18 cases of endometriosis involving ovaries and fallopian tubes, we identified three cases with foci of endometriosis adjacent to the embryonic duct remnants in the fallopian tube. The serial sections of the blocks of tissue containing areas of interest showed segments of embryonic duct remnants with changes suggestive of gradual transformation to endometrial glands. The early changes consisted of replacement of the muscular coat surrounding the epithelium of embryonic duct remnants by the endometrial stroma with positive immunoreactivities for estrogen receptor. Subsequently there were changes of the embryonic duct remnant epithelium into endometrial epithelium with diffuse immunoreactivities for estrogen receptor. The significance of this transformation as a mechanism of development of endometriosis is discussed.

Adult↗
PubMed1997

Pathogenetic role of the stromal cells in endometriosis and adenomyosis.

Ten cases of endometriosis of bowel, ovaries, uterine serosa and 10 cases of adenomyosis were studied. Blocks of tissue with areas of interest were submitted for serial sectioning of the entire block. Some sections were immunostained for oestrogen receptor, vimentin, Ber-EP-4 and cytokeratins. The common finding was the presence of type 1 nodules, consisting of isolated nodules of endometrial stromal cells without endometrial glands, along blood or lymphatic vessels. The stromal cells showed positive immunoreactivities for oestrogen receptor and vimentin, and negative reactivities for cytokeratins. Due to the absence of connection with adjacent endometriosis or adenomyosis, it is likely that these endometrial stromal nodules arise from the multipotential pericytes. In addition, in serosa of all cases of endometriosis, type 2 nodules, having adjacent mesothelium (Ber-EP4-) changing into epithelium (Ber-EP4+) and type 3 nodules, with non-endometrial epithelium (oestrogen receptor-) changing into endometrial gland (oestrogen receptor+) were identified. We believe that the formation of type 1 nodules from the pericytes and the transformation of the mesothelium into endometrial glands in type 2 and 3 nodules are accomplished through the process of induction by the endometrial stroma, and the proliferation is controlled by genetic, hormonal and immunological factors. Type 1, 2 and 3 nodules are likely to represent a histological continuum in the development of early endometriosis. Subsequent to the formation of endometriosis in the serosa, the pathway of development of endometriosis and adenomyosis is similar. Through the processes of induction and proliferation there is an increase in size of the stroma of type 1 nodules and that of endometrial tissue with subsequent fusion of the stroma of type 1 nodules and that of foci of adenomyosis or endometriosis. Consequently, there is enlargement of the stroma of the foci of adenomyosis or endometriosis. The 'newly enlarged stroma' serves as 'new soil' for further growth of the endometrial glands in the endometrial tissue.

Adult↗
PubMed1994

Unusual immunostaining pattern of chromogranin in normal urothelium and in transitional cell neoplasms.

We report an unusual pattern of immunostaining for chromogranin A in 24 transitional cell carcinomas (TCC). Positive immunostaining was seen with chromogranin A antisera in 10 of 16 urinary bladder TCC, neither of 2 prostatic TCC, 3 of 3 ureteral TCC and 2 of 3 metastatic TCC. This staining was demonstrated within the cytoplasm of transitional cells at all levels of the neoplastic epithelium, including cells near the basement membrane and at the free surface (umbrella cells). In 5 of 7 cases there was also immunoreactivity of the non-neoplastic urothelium. Immunostaining with neuron-specific enolase and synaptophysin was negative in all of these cases and no neuro-secretory granules were identified in 7 cases examined by electron microscopy. This pattern of immunostaining is probably due to reactivity with chromogranins or certain chromogranin-like proteins in the transitional cells, particularly in the umbrella cells.

Carcinoma, Transitional Cell↗
PubMed1992

HIV-1 sequence variation between isolates from mother-infant transmission pairs.

To examine the sequence diversity of human immunodeficiency virus type 1 (HIV-1) between known transmission sets, sequences from the V3 and V4-V5 region of the envelope gene from four mother-infant pairs were analyzed. The mean interpatient sequence variation between isolates from linked mother-infant pairs was comparable to the sequence diversity found between isolates from other close contacts. The mean intrapatient variation was significantly less in the infants' isolates then the isolates from both their mothers and other characterized intrapatient sequence sets. In addition, a distinct and characteristic difference in the glycosylation pattern preceding the V3 loop was found between each linked transmission pair. These findings indicate that selection of specific genotypic variants, which may play a role in some direct transmission sets, and the duration of infection are important factors in the degree of diversity seen between the sequence sets.

Adult↗
PubMed1989

Serological confirmation of human T-lymphotropic virus type I infection in healthy blood and plasma donors.

We wished to develop criteria for serological confirmation of human T-lymphotropic virus type I (HTLV-I) infection in healthy donors. Selected serum or plasma samples reactive by HTLV-I enzyme immunosorbent assay or gel-agglutination assays with at least one viral-specific band on Western immunoblot (WIB) were tested in six laboratories by four WIBs and four radioimmunoprecipitation assays (RIPAs) for antibodies to HTLV-I proteins encoded by gag (p19 and p24), env (gp46 and/or gp61), and tax (p40x) genes. One hundred forty-two donor sera were obtained from 38 Japanese, 69 American, and 35 Caribbean blood or plasma donors. Among these samples, WIB assays appeared more sensitive to p24 antibodies, whereas RIPAs were significantly more sensitive to gp61 antibodies. All sera (137) with gp61 antibodies had p24 antibodies. Of the 137 sera positive for p24 and gp61 antibodies, p19 antibodies were detected in 129 sera, and p40x antibodies were detected in 108. In sera with p19 antibodies and antibodies to env- or tax-encoded proteins, p24 antibodies were always present. Antibodies to p40x were not found in the absence of gp61 antibodies. Virological evidence of infection was found in seven American donors by lymphocyte coculture (one HTLV-I, one HTLV-II) or by polymerase chain reaction (three HTLV-I, two HTLV-II). Sera from all seven donors showed p24 and gp46 and/or gp61 antibodies. We suggest that seroreactivity to both p24 and gp46 and/or gp61 by WIB or RIPA or both are suitable criteria to confirm but not to distinguish HTLV-I and HTLV-II infections.

Blood Donors↗
PubMed1989

Renal disease in children with the acquired immunodeficiency syndrome.

Of 155 children with the acquired immunodeficiency syndrome (AIDS) whom we evaluated during a 6 1/2-year period, 12 were found to have proteinuria. Histologic studies of tissue from these 12 patients revealed a wide spectrum of renal disease: focal glomerulosclerosis in 5, mesangial hyperplasia in 5, segmental necrotizing glomerulonephritis in 1, and minimal change disease in 1. In addition, 6 had tubulointerstitial infiltrates, and 10 had glomerular dense deposits. All 10 renal specimens studied by electron microscopy contained endothelial tubuloreticular inclusions. The mean age (+/- SD) of the five patients with focal glomerulosclerosis when this condition was identified was 27 +/- 19 months. All five had severe renal failure within a year and died of other causes during the following year. The mean age of the five patients with mesangial hyperplasia was 38 +/- 31 months. Although none of them went on to have renal failure, four died within 8 +/- 7 months. Ten of the 12 patients with proteinuria died during the study period. Of the two surviving, one had mesangial hyperplasia and the other had minimal change disease. We conclude that children who acquire human immunodeficiency virus (HIV) infection during the perinatal period may have renal disease, most often focal glomerulosclerosis, as is the case in adults, or mesangial hyperplasia. Although 5 of the 12 children we studied had renal failure during the study period, none died of it. Further studies are needed to determine the correlations between clinical and pathological features and the pathophysiology of AIDS nephropathy in children.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Structure of the bovine elastin gene and S1 nuclease analysis of alternative splicing of elastin mRNA in the bovine nuchal ligament.

Genomic clones encompassing all the translated sequences, the 3' untranslated sequence, and 1 kb flanking the ATG translation initiation codon of bovine tropoelastin have been obtained and characterized by restriction enzyme analysis and extensive DNA sequencing. These analyses demonstrated that functionally distinct hydrophobic and cross-linking domains of the protein are segregated into separate exons throughout the gene. The putative promoter region lacks a TATA box, has an extremely high G+C content, and contains several SP1 binding sites. Comprehensive S1 analyses using probes covering the entire mRNA and RNA isolated from the nuchal ligament of bovine fetuses of different ages, neonate calves, and adult cows demonstrated that while only a single exon is alternatively spliced at high frequency, many exons are alternatively spliced at limited, variable frequencies. The results also suggest that such limited splicing is increased in the adult tissue relative to fetal and neonate tissues.

Amino Acid Sequence↗
PubMed1989

Human immunodeficiency virus and human T-cell leukemia virus type I in patients undergoing maintenance hemodialysis in Miami.

The high prevalence of human immunodeficiency virus (HIV-1) infection in populations at risk in Miami prompted a seroepidemiologic study of both HIV-1 and the human T-cell leukemia virus type I (HTLV-I), a closely related virus, in our patients receiving chronic hemodialysis. One hundred twenty-nine patients undergoing hemodialysis in 1986 and 1987 were tested for antibody against both viral antigens by EIA (Abbott Laboratories, Abbott Park, IL). Seroreactive samples for HIV-1 and/or HTLV-I were confirmed by Western blot and, for HTLV-I, by viral cultures. Thirty patients (23.2%) were positive for retroviral infection (22 for HIV-1 alone, four for HTLV-I alone, and four for both HIV-1 and HTLV-I). The most important risk factor was intravenous drug use, followed by blood transfusion. Patients with HIV-1 had lower T4-T8 ratios and higher mortality than those with HTLV-I infection alone. It was concluded that HTLV-I, as well as HIV-1, infection is endemic in chronic dialysis centers in Miami. The clinical consequences of HTLV-I infection in relatively immunocompromised patients with chronic uremia who are undergoing chronic hemodialysis remains to be established.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Evaluation of heterosexual partners, children, and household contacts of adults with AIDS.

Forty-five adults with the acquired immunodeficiency syndrome (AIDS) and their 45 spouses, 109 children, and 29 household contacts were studied for evidence of heterosexual, perinatal, and household spread of human T-cell lymphotropic virus type III (HTLV-III) infection. Of the 45 spouses enrolled, 26 (58%) had antibody to HTLV-III, including 12 (71%) of 17 male spouses and 14 (50%) of 28 female spouses. Of the 12 seropositive male spouses, nine were seropositive at enrollment and three had seroconversion. Of the 14 seropositive female spouses, four were seropositive at enrollment and ten seroconverted. Lack of barrier contraceptive use and oral sex were associated with seroconversion. Of the 109 children enrolled, 15 had AIDS or an AIDS-related illness, two had evidence of passive transfer of maternal antibodies, and two had HTLV-III infection acquired outside the household. None of the 90 seronegative children seroconverted. Of 29 household contacts studied, none developed antibody to HTLV-III.

Acquired Immunodeficiency Syndrome↗
PubMed1977

Transformation of nodular lymphoma to an immunoblastic IgM-producing tumor.

Two cases of nodular lymphocytic lymphoma that transformed into leukemic processes with IgM-kappa-type monoclonal proteins are reported. The transformations occurred 21 and 34 months after the diagnosis of lymphoma and were associated with rapid deterioration of the patients' conditions. The leukemic phase was characterized by plasmacytic and immunoblastic appearing lymphoid cells in the peripheral blood and marrow. Such transformation, though rare, is not unexpected in view of the currently postulated origin of nodular lymphomas in germinal center cells and of immunoglobulin-producing tumors in cells derived from germinal center cells.

Adult↗