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Biomedical subjects

S Pincus

Publications and source records attributed to S Pincus.

At least 55 records · Page 3Linked to original sources

Women in academic dermatology. Results of survey from the professors of dermatology.

BACKGROUND: A survey of the professors of dermatology addressed questions of recruitment and retainment of women in academic dermatology. One hundred thirteen questionnaires were distributed and tabulated anonymously. RESULTS: Most programs selected residents independent of gender. No gender-specific residency problems were identified other than clinical coverage and completion of training related to pregnancy and maternity leave. Less than 50% of departments have faculty development programs in place, though there was considerable support for faculty development programs and modification of tenure track. The number of women faculty was determined for all departmental faculty. Of the total faculty members, 28.1% were women. Of the paid faculty members, 30.7% were women compared with 24.8% of unpaid faculty members. For paid faculty, 10.7% of full professors were women, compared with 34.1% of associate professors and 38.1% of assistant professors. Only two department chairs were identified as women, though five additional women headed divisions. CONCLUSIONS: With regard to residency training, any problems appear to be reflections of anecdotal experience. With regard to faculty, this datum argues for barriers to advancement to positions with administrative responsibility. Strategies for increasing the number of women in senior positions will depend on recognition and encouragement of current women faculty and require a concerted effort to further professional growth and development, to reward academic success, to provide role models and mentors, and to recognize inherent conflicts of professional women.

Dermatology↗

Recombinant vaccinia virus producing the prM and E proteins of yellow fever virus protects mice from lethal yellow fever encephalitis.

Four recombinant vaccinia viruses were constructed for expression of different portions of the 17D yellow fever virus (YFV-17D) open reading frame. A recombinant, vP869, expressing prM and E induced high titers of neutralizing and hemagglutination inhibiting antibodies in mice and was protective against intracranial challenge with the French neurotropic strain of YFV. Levels of protection were equivalent to those achieved by immunization with the YFV-17D vaccine virus. Recombinant vaccinia viruses expressing E and NS1, C prM, E, NS1, or only NS1 failed to protect mice against challenge with YFV despite eliciting antibodies to NS1. The vP869-infected HeLa cells produced a particulate extracellular hemagglutinin (HA) similar to that produced by YFV-infected cells, supporting previous studies with Japanese encephalitis virus (Mason et al., 1991), suggesting that the ability of recombinant vaccinia virus to produce extracellular HA particles is important for effective flavivirus immunity.

Animals↗

Mice immunized with a subviral particle containing the Japanese encephalitis virus prM/M and E proteins are protected from lethal JEV infection.

Extracellular subviral particles produced by HeLa cells infected with a recombinant vaccinia virus encoding the prM and E genes of Japanese encephalitis virus (JEV) were purified and characterized. These particles contained the JEV prM/M and E proteins embedded in a lipid bilayer, and RNA was not detected in particles using the polymerase chain reaction and primers recognizing a part of the JEV E gene. The particles were uniformly spherical with a 20-nm diameter and had 5-nm projections on their surface. Mice that received a single inoculation of the purified extracellular particles emulsified with Freund's complete adjuvant were fully protected against 4.9 x 10(5) LD50 of JEV. Comparison of the neutralizing and hemagglutination-inhibiting antibody titers and radioimmunoprecipitation data showed that immunization with the particles induced an immune response similar to that following inoculation with the recombinant vaccinia virus.

Animals↗

A highly attenuated host range-restricted vaccinia virus strain, NYVAC, encoding the prM, E, and NS1 genes of Japanese encephalitis virus prevents JEV viremia in swine.

A highly attenuated strain of vaccinia virus (NYVAC) was engineered to express the Japanese encephalitis virus (JEV) prM, E, and NS1 genes or the prM and E genes. The recombinant viruses were tested as vaccine candidates in pigs, a natural host of JEV. JEV-neutralizing and hemagglutination-inhibiting antibodies appeared in swine sera 7 days after immunization with 10(8) PFU of the recombinant viruses and increased after a second dose at 28 days. The JEV levels detected in the serum after JEV challenge (d56) of the swine with 2 x 10(5) PFU of JEV were significantly reduced in animals inoculated with the recombinant viruses. These results demonstrate the ability of these NYVAC-vectored recombinants to protect pigs from JEV viremia.

Animals↗

Japanese encephalitis virus-vaccinia recombinants produce particulate forms of the structural membrane proteins and induce high levels of protection against lethal JEV infection.

Four recombinant vaccinia viruses were engineered for expression of different portions of the Japanese encephalitis virus (JEV) open reading frame. All four recombinant vaccinias contained the NS1 and NS2A genes, and each of these viruses specified the synthesis, glycosylation, and secretion of the nonstructural glycoprotein (NS1). All four recombinants also contained the E gene, and each virus correctly directed the synthesis and glycosylation of the envelope glycoprotein (E). Interestingly, two of these viruses (vP555 and vP650), which expressed the prM gene in addition to E and NS1, produced an extracellular hemagglutinin containing M and E that migrated in sucrose gradients similarly to the slowly-sedimenting hemagglutinin found in the culture fluid of JEV-infected cells. Immunization of 3-week-old mice with the recombinant viruses vP555 and vP658 resulted in immune responses to NS1, whereas only the virus that directed the synthesis of extracellular forms of E (vP555) induced an immune response to E. Both viruses provided protection against lethal challenge with JEV. Animals given two inoculations with vP555 were fully protected from greater than 10,000 LD50 of JEV. This high level of protection was correlated with the production of high titers of neutralizing and hemagglutination-inhibiting antibodies.

Animals↗

Comparison of protective immunity elicited by recombinant vaccinia viruses that synthesize E or NS1 of Japanese encephalitis virus.

Immunization with recombinant vaccinia viruses that specified the synthesis of Japanese encephalitis virus (JEV) glycoproteins protected mice from a lethal intraperitoneal challenge with JEV. Recombinants which coexpressed the genes for the structural glycoproteins, prM and E, elicited high levels of neutralizing (NEUT) and hemagglutination inhibiting (HAI) antibodies in mice and protected mice from a lethal challenge by JEV. Recombinants expressing only the gene for the nonstructural glycoprotein, NS1, induced antibodies to NS1 but provided low levels of protection from a similar challenge dose of JEV. Antibodies to the NS3 protein in postchallenge sera, representing the degree of infection with challenge virus, were inversely correlated to NEUT and HAI titers and levels of protection. These results indicate that although vaccinia recombinants expressing NS1 can provide some protection from lethal JEV infection, recombinants expressing prM and E elicited higher levels of protective immunity.

Animals↗

Vaccinia virus recombinants expressing either the measles virus fusion or hemagglutinin glycoprotein protect dogs against canine distemper virus challenge.

cDNA clones of the genes encoding either the hemagglutinin (HA) or fusion (F) proteins of the Edmonston strain of measles virus (MV) were expressed in vaccinia virus recombinants. Immunofluorescence analysis detected both proteins on the plasma membranes of unfixed cells as well as internally in fixed cells. Immunoprecipitation of metabolically radiolabeled infected-cell extracts by using specific sera demonstrated a 76-kDa HA polypeptide and gene products of 60, 44, and 23 kDa which correspond to a MV F precursor and cleavage products F0, F1, and F2, respectively. Neither recombinant induced cell fusion of Vero cells when inoculated individually, but efficient cell fusion was readily observed upon coinfection of cells with both recombinants. Inoculation of dogs with the vaccinia virus-MV F recombinant (VV-MVF) did not give rise to detectable MV-neutralizing antibody. Inoculation of dogs with the vaccinia virus-MV HA recombinant (VV-MVHA) or coinoculation with both recombinants (VV-MVF and VV-MVHA) induced significant MV-neutralizing titers that were increased following a booster inoculation. Inoculation of dogs with the vaccinia virus recombinants or with MV failed to induce canine distemper virus (CDV)-neutralizing antibodies. Upon challenge with a lethal dose of virulent CDV, signs of infection were observed in dogs inoculated with (VV-MVF). No symptoms of disease were observed in dogs that had been vaccinated with VV-MVHA or with VV-MVHA and VV-MVF and then challenged with CDV. All dogs vaccinated with the recombinant viruses as well as those inoculated with MV or a vaccine strain of CDV survived CDV challenge.

Animals↗

Poxvirus-based vectors as vaccine candidates.

The advent of recombinant DNA techniques and advances in immunology have provided a means for dissecting the immunobiology of disease-causing agents. Identification and expression of individual genes from the pathogens in heterologous systems, such as VV, have yielded valuable information regarding structural properties of the gene products and their role in eliciting protective immunity. Targets of both humoral and/or cellular immunity for many disease-causing agents have been identified or confirmed using a VV expression system (Section IV). Additionally, specific VV recombinants have induced a protective immune response in experimental animals. The ability of VV recombinants to induce pertinent immune responses necessary for protection, the potential to develop polyvalent vaccines, and the successful history of VV as an immunizing agent provide the impetus for engineering VV as a live recombinant vaccine candidate. Critical to the refinement of poxviruses as recombinant immunizing agents is a more in-depth knowledge of the molecular biology of these viruses. Although significant advances have been made in this area within the past 10 years, a greater understanding of the mechanisms governing gene expression and viral virulence factors should enable the development of more safe and effective vaccine candidates. Progression of VV vector technology to other members of the poxvirus family has been successful. Development of other poxviruses as vectors may, therefore, provide a means of generating host-restricted vaccines. Fowlpox recombinant viruses, for instance, may yield candidate vaccines in the poultry industry. Interestingly, it was also demonstrated that these host-restricted recombinant viruses can be used as immunizing vehicles in other species. The ability of a nonreplicating viral vector to elicit a protective immune response is especially intriguing in light of the observation by Morgan et al. that a VV/EBV gp340/220 recombinant, derived from an avirulent VV strain, was unable to protect cottontop tamarins from a live EBV challenge.

Animals↗

Removal of digoxin from the circulation using immobilized monoclonal antibodies.

High-affinity (Ka = 3.0 X 10(8) M-1) monoclonal antidigoxin antibodies were covalently coupled to Sepharose CL-6B, Bio Gel A5m, Affi-gel 15, and agarose:polyacrolein microsphere (APAM) beads. Antibody immobilized to these supports was characterized in its ability to remove digoxin in vitro from biological fluids. Equilibrium binding studies of digoxin in plasma revealed that antibody coupled to Sepharose, Bio Gel, and Affi-gel 15 retained 38-42% of theoretical binding capacity, whereas antibody coupled to APAM beads retained only 13%. Increasing flow rates from 0.5 to 5.0 mL/min across antibody immobilized to APAM beads decreased the removal of digoxin from plasma from 90 to 55%. In comparison, no decreases were observed in the amount of digoxin removed from plasma as the flow rates were increased across antibody immobilized to the other agarose supports. Antibody coupled to Affi-gel 15 was used for in vivo extracorporeal hemoperfusion studies. These studies indicated that although 5-20% of the total dose was removed from three guinea pigs, plasma digoxin levels were not lowered when compared with preperfusion concentrations. In addition, antibody columns which were reused following regeneration with glycine:HCl, pH 2.5 revealed that 80% of the original antibody activity was lost after two hemoperfusions. Hematological parameters were unchanged with the exception that platelets were significantly decreased following the 3-h perfusion study. These data indicate that immobilized antidigoxin antibodies were able to remove digoxin from the circulation, and immunoaffinity hemoperfusion may be a viable means of removing substances from blood.

Animals↗

HIV infection and developmental services for adults.

The achievement of community living and greater personal independence has placed adults with developmental disabilities in a potentially vulnerable position regarding acquisition of HIV infection. Early surveys have identified a limited number of individuals who have become infected. Few states have undertaken planning for assurance of appropriate services. Program managers must consider the diverse educational and ethical issues involved; advisory committees can be of assistance. Strong antidiscrimination measures will be required for the protection of adults with developmental disabilities and HIV infection.

Acquired Immunodeficiency Syndrome↗

Sexuality in the mentally retarded patient.

Physicians who provide care for mentally disabled patients are often confronted with perplexing decisions involving sexuality, contraception and marriage. In the face of uncertainty, the physician may take the path of least resistance, which may not be the best solution for the patient. For example, it is not widely known that marriages among mentally retarded individuals can provide stability and considerable satisfaction.

Adult↗

Skin as the site of vitamin D synthesis and target tissue for 1,25-dihydroxyvitamin D3. Use of calcitriol (1,25-dihydroxyvitamin D3) for treatment of psoriasis.

Vitamin D is a hormone, not a vitamin. The skin is responsible for producing vitamin D. During exposure to sunlight, ultraviolet radiation penetrates into the epidermis and photolyzes provitamin D3 to previtamin D3. Previtamin D3 can either isomerize to vitamin D3 or be photolyzed to lymisterol and tachysterol. Vitamin D is also sensitive to sunlight and is photolyzed to 5,6-transvitamin D3, suprasterol I, and suprasterol II. In Boston, solar irradiation only produces previtamin D3 in the skin between the months of March and October. Aging, sunscreens, and melanin all diminish the capacity of the skin to produce previtamin D3. Once formed, vitamin D3 enters the circulation and is sequentially metabolized to 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 (1,25-[OH]2-D3). The epidermis possesses receptors for 1,25-(OH)2-D3. 1,25-(OH)2-D3 inhibits the proliferation of cultured keratinocytes and induces them to terminally differentiate. The topical or oral administration of 1,25-(OH)2-D3 has proved to be effective for the treatment of psoriasis. Therefore, the skin is the site for the synthesis of vitamin D and a target tissue for its active metabolite. The successful use of 1,25-(OH)2-D3 for the treatment of psoriasis heralds a new approach for the treatment of this enigmatic disorder.

Calcitriol↗

The inhibition of both initiation and elongation of adenovirus DNA replication by actinomycin D.

The effect of actinomycin D on adenovirus DNA replication has been examined both in vivo and in a cell-free extract capable of replication on exogenously added template. In both cases we show that 5 micrograms/ml of drug cause an inhibition of DNA synthesis of at least 80%. The in vitro results further demonstrate that both DNA chain growth (elongation) and initiation - the addition of the first nucleotide of the DNA chain (dCMP) to the preterminal protein - are inhibited directly by the drug, by not by alpha-amanitin.

Adenoviridae↗

A simple and sensitive solid-phase radioimmunoassay for the assay of human TSH antibody. Use in screening hybridoma cell lines.

A simple and sensitive radioimmunoassay procedure is described for the screening and detection of specific antibodies in hybridoma cell lines. The specific procedure was developed to screen for antibodies against human thyrotropin (hTSH), but the procedure is applicable to screening for any desired antibodies. The immunoglobulin G(IgG) fraction of goat anti-mouse IgG is used to coat wells of microtiter plates. Anti-hTSH antibodies are measured by incubating antiserum dilutions in the coated wells and detecting the bound IgG with radioiodinated hTSH. Unlabeled hTSH may also be detected by its ability to inhibit binding of 125I-hTSH to the coated wells. This assay technique meets the demands of simplicity, sensitivity, reproducibility, and rapidity as a screening assay of hybridoma cell lines capable of secreting anti h-TSH.

Animals↗

Eosinophil activation by colony-stimulating factor in man: metabolic effects and analysis by flow cytometry.

Substantial increases in the killing capacity of human eosinophils after in vitro incubation with human placental conditioned medium (HPCM), a standard source of colony-stimulating factor (CSF), have recently been described. In this article, the interaction between HPCM and purified human eosinophils is analyzed by flow cytometry and by effects on iodination, superoxide production, and protein synthesis. HPCM increased the intensity of natural eosinophil autofluorescence (aFlu) (460 nm) after the absorption of ultraviolet light (360 nm) in a manner that was both time and dose dependent. Measured in arbitrary units, eosinophil aFlu was 72 +/- 7.3 (arithmetic mean +/- SEM) and 121 +/- 3.2 after 18-hr incubations in the absence or presence of HPCM, respectively. The activity in HPCM responsible for these changes cochromatographed on Ultrogel AcA44 columns with CSF and with the less hydrophobic variant of CSF (CSF-alpha) on phenyl Sepharose. Mouse spleen, but not mouse lung, conditioned medium was also active on human eosinophils in this assay. Both CSF-alpha and mouse spleen conditioned medium also contain eosinophil colony-stimulating activity (CSA), whereas inactive CSFs with no effect on mature eosinophils, CSF-beta, and mouse lung conditioned medium also lack eosinophil CSA. CSF-alpha stimulated superoxide production of resting eosinophils (from 0.03 +/- 0.03 to 0.47 +/- 0.08 nmole cytochrome-c reduced/10(5) eosinophils) and of eosinophils incubated with preopsonized zymosan (from 0.15 +/- 0.06 to 0.73 +/- 0.07). It also stimulated iodination by resting eosinophils (from 0.76 +/- 0.16 to 2.60 +/- 0.72 nmoles l/10(7) eosinophils/hr) and of eosinophils incubated with preopsonized zymosan (from 7.52 +/- 2.08 to 29.8 +/- 1.32). In contrast, CSF-beta was inactive in these assays. CSF-alpha also stimulated, between 2- and 15-fold, the new protein synthesis of eosinophils. Thus, substances that stimulate the differentiation of progenitor cells into eosinophils also interact with peripheral mature eosinophils, and the activation of postmitotic cells may be a physiologic role of CSF-like molecules.

Cell Separation↗