Biomedical subjects

M Wade

Publications and source records attributed to M Wade.

At least 55 records · Page 3Linked to original sources

PubMed1995

Interaction of the 72-kilodalton human cytomegalovirus IE1 gene product with E2F1 coincides with E2F-dependent activation of dihydrofolate reductase transcription.

Three polypeptides are produced from the major immediate-early (IE) region of human cytomegalovirus by alternative splicing. The IE gene products regulate subsequent viral and cellular gene expression. We previously reported that cotransfection of a genomic clone of the major IE region stimulated transient expression of chloramphenicol acetyltransferase driven by the dihydrofolate reductase (DHFR) promoter and that an intact E2F site was required for the trans activation (M. Wade, T. F. Kowalik, M. Mudryj, E.-S. Huang, and J. C. Azizkhan, Mol. Cell. Biol. 12:4364-4374, 1992). With the availability of cDNA clones for the individual major IE proteins, we sought to determine which of these proteins exerted this effect and whether the IE protein(s) interacted with E2F. In this study, we use cotransfection to demonstrate that the 55- and 86-kDa major IE proteins from the IE2 region can each moderately trans activate the DHFR promoter and that the 72-kDa IE1 protein stimulates DHFR transcription to a much higher level. Furthermore, trans activation through the 72-kDa IE1 protein is in part E2F dependent, while activation by the 55- and 86-kDa IE proteins is E2F independent. We also demonstrate by in vitro pull-down assays that the 72-kDa IE1 protein can specifically interact with the DNA binding domain of E2F1 (amino acids 88 to 191) in the presence of nuclear extract. Moreover, antibodies to either E2F1 or IE72 will immunoprecipitate both E2F and IE72 from cells that stably express IE72, and antibody to E2F1 will immunoprecipitate IE72 from normal human fibroblast cells infected with human cytomegalovirus.

Base Sequence↗

PubMed1995

The relative cost of Medicaid enrollees and the commercially insured in HMOs.

Under several national health care reform proposals in 1994, many Medicaid beneficiaries would have enrolled in health maintenance organizations (HMOs) with other persons. Several states already enroll Medicaid beneficiaries in HMOs with commercial enrollees. This DataWatch examines the cost of Medicaid enrollees in HMOs relative to the cost of commercial enrollees. Data from nine HMOs indicate that, on average, Aid to Families with Dependent Children (AFDC) and poverty-related Medicaid enrollees cost 13 percent more than commercial enrollees cost. If one adjusts for enrollees' age and sex, Medicaid costs are 23 percent higher than commercial costs.

Data Collection↗

PubMed1995

Causes of Medicaid expenditure growth.

Expenditures for the Medicaid program grew at the alarming and unexpected average annual rate of nearly 20 percent from 1989 ($58 billion) to 1992 ($113 billion). These statistics raise a critical question: What caused spending to grow so dramatically? Using State-level data from 1984-92, this analysis examines the determinants of Medicaid expenditure growth. The results indicate that Medicaid enrollment, Federal Medicaid policy, and State policy are significantly related to Medicaid expenditure growth. The analysis also finds the prevalence of acquired immunodeficiency syndrome (AIDS) to be significantly related to Medicaid expenditures.

Acquired Immunodeficiency Syndrome↗

PubMed1993

Percutaneous absorption of pentachlorophenol from soil.

Pentachlorophenol (PCP) is one of the most heavily used pesticides. About 80% of PCP is used for wood preservation, whereas the remainder is used as an herbicide, fungicide, and disinfectant. PCP is a probable human carcinogen, based on animal studies. Illness and death have been reported where PCP is in direct contact with skin. PCP is the most ubiquitous compound found when the general population is screened for pesticide residue. PCP is found in soil as well as other environmental sources. Our objective was to determine the skin bioavailability of PCP from soil and from the control vehicle acetone. In vivo in the Rhesus monkey, percutaneous absorption of PCP was 24.4 +/- 6.4% of applied dose from soil and 29.2 +/- 5.8% of applied dose from acetone vehicle for a 24-hr exposure period. This amount of absorption makes PCP one of the more extensively absorbed compounds to date. Additionally, the 14C half-life was 4.5 days following both intravenous and skin administration of [14C]PCP. These data suggest high bioavailability and an extended biological interaction period with the long half-life. In vitro percutaneous absorption with human cadaver skin and human plasma receptor fluid underestimated the in vivo absorption. Receptor fluid accumulation was 0.6 +/- 0.09% and 1.5 +/- 0.2% for two skin sources for PCP in acetone vehicle and 0.01 +/- 0.00% and 0.00 +/- 0.08% for two skin sources with soil vehicle. Skin content after skin surface wash ranged from 2.6 to 3.7% for acetone vehicle and 0.07-0.11% for soil vehicle. Overall accountability for in vitro dose ranged from 81 to 96%.

Acetone↗

PubMed1993

In vivo and in vitro percutaneous absorption and skin decontamination of arsenic from water and soil.

The objective was to determine the percutaneous absorption of arsenic-73 as H3ASO4 from water and soil. Soil (Yolo County 65-California-57-8) was passed through 10-, 20-, and 48-mesh sieves. Soil retained by 80 mesh was mixed with radioactive arsenic-73 at a low (trace) level of 0.0004 microgram/cm2 (micrograms arsenic per square centimeter skin surface area) and a higher dose of 0.6 micrograms/cm2. Water solutions of arsenic-73 at a low (trace) level of 0.000024 micrograms/cm2 and a higher dose of 2.1 micrograms/cm2 were prepared for comparative analysis. In vivo in Rhesus monkey a total of 80.1 +/- 6.7% (SD) intravenous arsenic-73 dose was recovered in urine over 7 days; the majority of the dose was excreted in the first day. With topical administration for 24 hr, absorption of the low dose from water was 6.4 +/- 3.9% and 2.0 +/- 1.2% from the high dose. In vitro percutaneous absorption of the low dose from water with human skin resulted in 24-hr receptor fluid (phosphate-buffered saline) accumulation of 0.93 +/- 1.1% dose and skin concentration (after washing) of 0.98 +/- 0.96%. Combining receptor fluid accumulation and skin concentration gave a combined amount of 1.9%, a value less than that in vivo (6.4%) in the Rhesus monkey. From soil, receptor fluid accumulation was 0.43 +/- 0.54% and skin concentration was 0.33 +/- 0.25%. Combining receptor fluid plus skin concentrations gave an absorption value of 0.8%, an amount less than that with in vivo absorption (4.5%) in the Rhesus. These absorption values did not match current EPA default assumptions.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗

PubMed1993

Percutaneous absorption of PCBs from soil: in vivo rhesus monkey, in vitro human skin, and binding to powdered human stratum corneum.

Polychlorinated biphenyls (PCBs) are ubiquitous and persistent environmental pollutants. The major resident site for these PCBs is the soil, and human skin is frequently in contact with soil. Our objective was to determine the percutaneous absorption of the PCBs Aroclor 1242 and Aroclor 1254 from soil. PCB-contaminated soil was prepared at levels of 44 ppm Aroclor 1242 and 23 ppm Aroclor 1254. PCB concentrations on skin were 1.75 micrograms/cm2 for Aroclor 1242 and 0.91 microgram/cm2 for Aroclor 1254. In vivo percutaneous absorption in the rhesus monkey was determined by urinary and fecal [14C]-PCB excretion for a 5-wk period following topical dosing. Absorption of Aroclor 1242 was determined in vitro with human skin for comparative purposes. In vivo in the rhesus monkey the percutaneous absorption of Aroclor 1242 was 13.8 +/- 2.7 (SD)% of the dose and the absorption of Aroclor 1254 was 14.1 +/- 1.0%. These absorption amounts are similar to the absorption of Aroclor 1242 and 1254 from other vehicles (mineral oil, trichlorobenzene, acetone). With in vitro percutaneous absorption through human skin, most of the Aroclor 1242 and Aroclor 1254 resided in the skin and the amounts were dependent upon dosing vehicle (water > mineral oil > soil). Both PCBs readily partitioned from water into soil and human powdered stratum corneum. By difference the partitioning favored both PCBs going from soil into stratum corneum. These data emphasize the role of soil in percutaneous absorption and provide information for appropriate risk assessment.

Administration, Topical↗

PubMed1993

Use of osseointegrated implants to support a maxillary denture for a patient with repaired cleft lip and palate.

Although many cleft lip and palate patients retain their dentition, some develop partial or complete edentulism. The configuration of the residual maxillary alveolar ridge may provide little support for a complete or partial maxillary denture. The success of the Branemark dental implant has been well established, and although placement of implants in the maxilla may present a surgical challenge, implants are very effective in providing support and, therefore, retention and stability. Application of implants to the cleft palate maxilla is particularly valuable because of the difficulty in constructing well-fitting conventional dentures for CLP patients, and the relatively compromised nature of the prostheses when made. This report presents the prosthetic treatment of a nearly edentulous cleft lip and palate patient.

Cleft Lip↗

PubMed1993

The impact of Medicaid adoption of the Medicare fee schedule.

In this article, the authors simulate the effects on Federal and State Medicaid expenditures of increasing Medicaid fees to Medicare fee schedule (MFS) levels. Strict adoption of the MFS by the States would increase total Medicaid spending by approximately 4 percent, $2.5 to $2.9 billion. Because Medicaid fees vary across States, so does the impact of adopting the MFS. Medicaid spending would increase significantly in some wealthy States with large Medicaid populations and in a few small, relatively poor States. Some States currently pay more than the MFS for obstetrical services. If these fees continued at higher levels for obstetrical care, total Medicaid spending would increase by $3.5 to $4.0 billion.

Adult↗

PubMed1993

Transcription from TATA-less promoters: dihydrofolate reductase as a model.

The promoters of many of the genes encoding the so-called "housekeeping" enzymes, oncogenes, growth factors and their receptors, and transcription factors, do not contain a canonical TATA box, which is known to direct transcription initiation. The mechanisms through which TATA-less promoters are regulated, and their transcription start sites selected, have begun to yield to investigation. Using the dihydrofolate reductase (DHFR) gene as a model, recent work on this group of genes has been reviewed. Control of transcription initiation and the role of "initiator" sequences, as well as their binding factors, in particular YY1 and E2F, are addressed. In the DHFR gene, neither the E2F site at the major initiation region nor the upstream Sp1 sites can alone produce wild-type initiation, despite the fact that each of these sites has certain properties of initiators. Many TATA-less genes are growth regulated, that is, transcription is increased in response to stimulation of cell proliferation. Although both Sp1 and E2F have been implicated in growth regulation, our recent studies suggest that Sp1 sites alone can confer a growth-dependent increase in transcription in the late G1 and early S phases of the cell cycle. The regulatory role of E2F, which binds to many TATA-less promoters and mediates viral stimulation of transcription, is also reviewed.

Animals↗

PubMed1992

In vitro percutaneous absorption of cadmium from water and soil into human skin.

The objective was to determine percutaneous absorption of cadmium as the chloride salt from water and soil into and through human skin. Soil (Yolo County 65-California-57-8) was passed through 10-, 20-, and 48-mesh sieves. Soil retained by 80 mesh was mixed with radioactive cadmium-109 at 13 ppb. Water solutions of cadmium-109 at 116 ppb were prepared for comparative analysis. Human cadaver skin was dermatomed to 500-microns, and used in glass diffusion cells with human plasma as the receptor fluid (3 ml/hr flow rate) for a 16-hr skin application time. Cadmium in water (5 microliters/cm2) penetrated skin to concentrations of 8.8 +/- 0.6 and 12.7 +/- 11.7% of the applied dose from two human skin sources. Percentage doses absorbed into plasma were 0.5 +/- 0.2 and 0.6 +/- 0.6%, respectively. Cadmium from soil (0.04 g soil/cm2) penetrated skin at concentrations of 0.06 +/- 0.02 and 0.13 +/- 0.05% for the two human skin sources. Amounts absorbed into plasma were 0.01 +/- 0.01 and 0.07 +/- 0.03%. Most of the nonabsorbed cadmium was recovered in the soap and water skin surface wash. Binding of cadmium from water to soil was greater than binding from water to powdered human stratum corneum, supporting the lower absorption from soil than from water. Short-term exposure of cadmium in water to human skin for 30 min (bath or swim) resulted in skin uptake, which upon further perfusion (48 hr), absorbed into the plasma receptor fluid (systemic). Cadmium in soil was increased from 6.5 to 65 ppb.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗

PubMed1992

E2F mediates dihydrofolate reductase promoter activation and multiprotein complex formation in human cytomegalovirus infection.

The adenovirus immediate-early protein E1A activates the adenovirus E2 promoter and several cellular gene promoters through transcription factor E2F. The immediate-early proteins of human cytomegalovirus (HCMV) can complement an E1A-deficient adenovirus mutant and activate the adenovirus E2 promoter. HCMV also has been shown to activate the adenovirus E2 promoter. On the basis of these findings, we have investigated whether HCMV can activate the promoter of the cellular dihydrofolate reductase (DHFR) gene, which requires E2F binding for maximal promoter activity. We show that HCMV activates the DHFR promoter and that products of the HCMV major immediate-early gene region mediate the activation of the promoter specifically through the E2F site. We used gel mobility shift assays to search for potential molecular mechanisms for this activation and found an "infection-specific" multimeric complex that bound to the E2F sites in the DHFR and E2 promoters in extracts from HCMV-infected cells but not in extracts from uninfected cells. Several antibodies against HCMV immediate-early gene products had no effect on this infection-specific complex. Subsequently, the complex was found to contain E2F, cyclin A, p33cdk2, and p107 and to be similar to S-phase-specific complexes that recently have been identified in several cell types. A functional role for the binding of the cyclin A-p33cdk2 complex to cellular gene promoters has yet to be demonstrated; however, HCMV infection causes the induction of both cellular DNA replication and transcription of growth-related genes containing E2F sites in their promoters. The findings described above therefore may relate to both of these effects of HCMV infection. We also provide evidence that some of the molecular events associated with adenovirus infection are different from those associated with HCMV infection.

Animals↗

PubMed1990

Falloposcopy: a microendoscopic technique for visual exploration of the human fallopian tube from the uterotubal ostium to the fimbria using a transvaginal approach.

A transvaginal microendoscopic technique has been developed for safely exploring the human fallopian tube from the utero tubal ostium to the fimbria and adjacent peritoneal cavity. Falloposcopy was performed without complication or evidence of endotubal damage in 44 women, 38 of whom also underwent a concurrent laparoscopy. Eight women with normal tubes served as controls and 36 women with tubal damage underwent falloposcopy in an attempt to document endotubal defects. Previous salpingectomy in 13 women and ostial obstruction in 4 cases left 71 tubes available for falloposcopy. Technical failures, defined as an inability to negotiate the tubal lumen in the absence of obstructive disease occurred in 8 of 71 (11%) procedures. In 63 successful procedures, the tubal lumen was considered to be falloposcopically normal in 28 cases (44%) and contained defects ranging from partial to total obstruction secondary to intraluminal fibrosis within the intramural, isthmic, and ampullary segments in the remaining 35 tubes (56%). Falloposcopy provides a nonincisional modality for defining the normal and abnormal surface anatomy of the tubal epithelium.

Endothelium↗

PubMed1989

Altered regulation of intercellular communication by epidermal growth factor, transforming growth factor-beta and peptide hormones in normal human keratinocytes.

Since many chemical tumor promoters and some oncogenes have been shown to inhibit gap junction-mediated intercellular communication, the effect of various growth factors on gap junctional intercellular communication on normal human keratinocytes was examined. In order to measure the effect of the growth factors on gap junctional communication, the scrape loading/dye transfer technique was used on human keratinocytes grown in a serum-free medium in vitro. At 24 h after treatment epidermal growth factor (10 ng/ml), transforming growth factor-beta (1 ng/ml), whole bovine pituitary extract (70 micrograms/ml) and 12-O-tetradecanoylphorbol-13-acetate (TPA) (100 ng/ml) inhibited intercellular communication. Treatment of these cells with transforming growth factor-beta (1 ng/ml) induced morphological changes in some of the cells and brought about selective intercellular communication within and between the nonaltered and altered cells. Epidermal growth factor and whole bovine pituitary extract, significantly enhanced [3H]thymidine uptake and also stimulated cellular proliferation under the experimental conditions used to inhibit intercellular communication. Both transforming growth factor-beta and TPA markedly inhibited [3H]thymidine uptake and induced differentiation of some of these cells. In order to study the possible mechanism by which the growth factors might inhibit intercellular communication, the effect of the growth factors on protein kinase C activation and alterations of intracellular free calcium was investigated. The results indicated that neither protein kinase C nor an increase in [Ca2+]i were involved in the modulation of gap junctional communication by epidermal growth factor or transforming growth factor-beta. The study suggests that in the human keratinocytes inhibition of intercellular communication may be involved (i) in the action of growth factors such as epidermal growth factor during cellular proliferation and (ii) in the differentiation of primary keratinocytes by transforming growth factor-beta.

Calcium↗

PubMed1989

Alpha-thalassemia changes the cell density profile in sickle cell anaemia.

Several factors are implied in the haematological and clinical picture of sickle cell anaemia. Attention has been focused on the concomitant presence of -alpha-thalassemia and high levels of HbF, but contradictory results have been reported in different populations. We compared the blood cell density profile, obtained by the phtalate esther method, of normal subjects with those of patients with sickle cell anaemia - with or without heterozygous alpha-thalassemia. We found that the density profile of both groups of patients differs from normal subjects, and that a difference can also be demonstrated between normal alpha genotype patients with sickle cell anaemia and patients with heterozygous alpha-thalassemia. These results are in agreement with the findings obtained in other countries in which a gene from Caucasian to African populations have been demonstrated, and are different from the results obtained in populations of more pure African ancestry. It can be suggested, therefore, that these data, in addition with findings of other authors in different geographical areas, support the hypothesis that the genetic make up plays an important role in the haematologic and clinical picture of sickle cell anaemia.

Anemia, Sickle Cell↗

PubMed1988

The efficacy of starting postterm antenatal testing at 41 weeks as compared with 42 weeks of gestational age.

Postterm antenatal fetal surveillance has traditionally begun at 42 completed weeks of gestation. However, recent data have shown that a significant percentage of cases of perinatal asphyxia occurs between 40 and 42 weeks of gestation. We compared the perinatal outcome of fetuses with antenatal surveillance beginning at 41 weeks to those starting at 42 weeks of gestation. The study groups consisted of 908 patients who began antenatal testing at 41 weeks and 352 who began testing at 42 weeks. Antenatal testing consisted of twice-weekly amniotic fluid assessments and nonstress tests (including evaluation for late and variable decelerations). Between 41 and 42 weeks, the group whose testing started at 41 weeks had an overall incidence of intrapartum fetal distress of 2.7%, no stillbirths, and no infants with major neonatal morbidity. Patients without antenatal testing who delivered between 41 to 42 weeks did not have a significantly increased incidence of fetal distress (3.3%; p = 0.07). However, this group had a significantly increased incidence of adverse outcomes (p less than 0.05), including three stillbirths and seven cases of major neonatal morbidity. Beyond 42 weeks, the group whose testing started at 41 weeks had a 2.3% overall incidence of fetal distress. This was significantly less (p less than 0.01) than the group whose testing started at 42 weeks (5.6%). Neither of the groups had any stillbirths or infants with major neonatal morbidity. These findings suggest that starting antenatal testing at 41 weeks of gestation may result in decreased postterm perinatal mortality and morbidity as well as a decreased incidence of intrapartum fetal distress.

Female↗

PubMed1987

Endogenous lectins from cultured cells: nuclear localization of carbohydrate-binding protein 35 in proliferating 3T3 fibroblasts.

Proliferating 3T3 mouse fibroblasts contain higher levels of the lectin carbohydrate-binding protein 35 (CBP35) than do quiescent cultures of the same cells. An immunofluorescence study was carried out with a rabbit antiserum directed against CBP35 to map the cellular fluorescence distribution in a large population of cells under different growth conditions. This cytometric analysis showed that the lectin is predominantly localized in the nucleus of the proliferating cells. In quiescent 3T3 cultures, the majority of the cells lost their nuclear staining and underwent a general decrease in the overall fluorescence intensity. Stimulation of serum-starved quiescent 3T3 cells by the addition of serum resulted in an increase in the level of CBP35. The percentage of cells showing distinct punctate intranuclear staining reached a maximum at about the same time as the onset of the first S-phase of the cell cycle. All of these results suggest that CBP35 may be a protein whose presence in the nucleus, in discrete punctate distribution, is coordinated with the proliferation state of the cell.

Animals↗

PubMed1985

Biologically active peptides of the vesicular stomatitis virus glycoprotein.

A peptide corresponding to the amino-terminal 25 amino acids of the mature vesicular stomatitis virus glycoprotein has recently been shown to be a pH-dependent hemolysin. In the present study, we analyzed smaller constituent peptides and found that the hemolytic domain resides within the six amino-terminal amino acids. Synthesis of variant peptides indicates that the amino-terminal lysine can be replaced by another positively charged amino acid (arginine) but that substitution with glutamic acid results in the total loss of the hemolytic function. Peptide-induced hemolysis was dependent upon buffer conditions and was inhibited when isotonicity was maintained with mannitol, sucrose, or raffinose. In sucrose, all hemolytic peptides were also observed to mediate hemagglutination. The large 25-amino acid peptide is also a pH-dependent cytotoxin for mammalian cells and appears to effect gross changes in cell permeability. Conservation of the amino terminus of vesicular stomatitis virus and rabies virus suggests that the membrane-destabilizing properties of this domain may be important for glycoprotein function.

Amino Acid Sequence↗

PubMed1984

A synthetic peptide corresponding to the NH2 terminus of vesicular stomatitis virus glycoprotein is a pH-dependent hemolysin.

The spike protein of vesicular stomatitis virus, G protein, is a 68,000-Da glycoprotein which mediates viral binding, membrane fusion, and hemolysis. In an attempt to define the protein domain involved in membrane destabilization and fusion, a 25-amino acid peptide corresponding to the NH2 terminus of G protein was synthesized. We show here that this peptide is a pH-dependent hemolysin and that the pH and temperature optima for hemolysis by peptide and virus are similar. Antiserum prepared against this peptide is nonneutralizing and nonreactive with native G protein. Antipeptide antibodies, however, do react with sodium dodecyl sulfate-denatured protein, suggesting that the G protein NH2 terminus is "masked" in the native protein. The hemolytic activity of the synthetic peptide may reflect an analogous function of the NH2 terminus of G protein.

Amino Acid Sequence↗