Power and pollutant exposure in the context of American Indian health and survival.

BACKGROUND: American Indians and Alaskan Natives (AI/AN) are a highly diverse group in terms of culture and language, but share a history of oppression and attempted extermination that has left many with a legacy of poverty and poor health. Cultural and biological survival are important issues for many AI/AN groups. METHODS: Using US criteria, AI/AN groups are more likely to be poor. The US National Center for Health Statistics reports that US AI/ANs have higher mortality and morbidity rates than the US population. While all groups racially defined by the US National Center for Health Statistics have been experiencing a decline in fertility since 1983, AI/ANs seem to be suffering a substantially greater and earlier decline in fertility. Given the importance of fertility in the survival of AI/AN communities, it is important to identify the source of this decline. RESULTS: A recent study of one AI/AN group living along the St. Lawrence River found that obesity and exposure to a particular group of polychlorinated biphenyls were the factors most highly associated with indicators of impaired fertility. Economic factors are often cited as reasons for fertility declines, however in this situation these other factors may have either primary or contributing roles. CONCLUSIONS: If the associations with obesity and toxicant exposure are confirmed, intervening on these factors might be important steps in stemming continued declines in fertility.

The role of phosphatase and tensin homolog in drug-induced gingival overgrowth.

BACKGROUND AND OBJECTIVE: We proposed that phosphatase and tensin homolog (PTEN) might be one of the signaling proteins that alter the balance between cell growth and cell death in drug-induced gingival overgrowth. The aim of this study was to investigate the expression of PTEN in subjects using cyclosporine A and to analyze the relationship between PTEN and cell proliferation marker, proliferating cell nuclear antigen (PCNA), in cyclosporine A-induced gingival overgrowth. MATERIAL AND METHODS: In total, samples from 36 subjects, i.e. 24 cyclosporine A-mediated renal transplant patients with gingival overgrowth (n = 12) or without gingival overgrowth (n = 12) and 12 matched periodontally healthy subjects, were included in the study. PTEN and PCNA expressions in gingival tissues were analyzed using immunohistochemistry, PTEN expression was also analyzed by western blot. PTEN immunoreactivity was calculated with a histologic score (HSCORE) value and PCNA immunoreactivity was calculated with the PCNA-proliferative index. RESULTS: Phosphatase and tensin homolog HSCORE for the group with gingival overgrowth was found to be significantly lowest compared to the group without gingival overgrowth and the control group (p < 0.001) while the highest PTEN HSCORE was found in the control group. In addition, the PTEN HSCORE for the group without gingival overgrowth was significantly lower compared to controls (p < 0.001). The highest PCNA-proliferative index score was observed in the group with gingival overgrowth while the lowest score was observed in the control group (p < 0.001). The immunoblot signal for PTEN was significantly decreased in the group with gingival overgrowth compared to the group without gingival overgrowth and the control group (p < 0.001). Western blot results were different from immunohistochemistry and revealed there was no significant difference between the without gingival overgrowth and the control group (p > 0.05). CONCLUSION: Our results showing decreased PTEN levels in patients with gingival overgrowth supported with increased PCNA expression suggested that PTEN might take part in the imbalance between cell proliferation and death in drug-induced gingival overgrowth.

Virus-specific cytotoxic T-lymphocyte responses select for amino-acid variation in simian immunodeficiency virus Env and Nef.

Cytotoxic T-lymphocyte (CTL) responses to human immunodeficiency virus arise early after infection, but ultimately fail to prevent progression to AIDS. Human immunodeficiency virus may evade the CTL response by accumulating amino-acid replacements within CTL epitopes. We studied 10 CTL epitopes during the course of simian immunodeficiency virus disease progression in three related macaques. All 10 of these CTL epitopes accumulated amino-acid replacements and showed evidence of positive selection by the time the macaques died. Many of the amino-acid replacements in these epitopes reduced or eliminated major histocompatibility complex class I binding and/or CTL recognition. These findings strongly support the CTL 'escape' hypothesis.

Engagement of the PD-1 immunoinhibitory receptor by a novel B7 family member leads to negative regulation of lymphocyte activation.

PD-1 is an immunoinhibitory receptor expressed by activated T cells, B cells, and myeloid cells. Mice deficient in PD-1 exhibit a breakdown of peripheral tolerance and demonstrate multiple autoimmune features. We report here that the ligand of PD-1 (PD-L1) is a member of the B7 gene family. Engagement of PD-1 by PD-L1 leads to the inhibition of T cell receptor-mediated lymphocyte proliferation and cytokine secretion. In addition, PD-1 signaling can inhibit at least suboptimal levels of CD28-mediated costimulation. PD-L1 is expressed by antigen-presenting cells, including human peripheral blood monocytes stimulated with interferon gamma, and activated human and murine dendritic cells. In addition, PD-L1 is expressed in nonlymphoid tissues such as heart and lung. The relative levels of inhibitory PD-L1 and costimulatory B7-1/B7-2 signals on antigen-presenting cells may determine the extent of T cell activation and consequently the threshold between tolerance and autoimmunity. PD-L1 expression on nonlymphoid tissues and its potential interaction with PD-1 may subsequently determine the extent of immune responses at sites of inflammation.

The pheromone of the cave cricket, Hadenoecus cumberlandicus, causes cricket aggregation but does not attract the co-distributed predatory spider, Meta ovalis.

Food input by the cave cricket, Hadenoecus cumberlandicus Hubble & Norton (Orthoptera: Rhaphidophoridae), is vital to the cave community, making this cricket a true keystone species. Bioassays conducted on cave walls and in the laboratory show that clustering in H. cumberlandicus is guided by a pheromone, presumably excreta. This aggregation pheromone was demonstrated by using filter paper discs that had previous adult H. cumberlandicus exposure, resulting in > 70% response by either nymphs or adults, prompting attraction (thus, active component is a volatile), followed by reduced mobility (arrestment) on treated surfaces. Adults were similarly responsive to pheromone from nymphs, agreeing with mixed stage composition of clusters in the cave. Effects of [0.001 M - 0.1 M] uric acid (insect excreta's principle component) on H. cumberlandicus behavior were inconsistent. This pheromone is not a host cue (kairomone) and is not used as a repellent (allomone) as noted through lack of responses to natural H. cumberlandicus pheromone and uric acid concentrations by a co-occurring predatory cave orb weaver spider, Meta ovalis Gertsch (Araneae: Tetragnathidae). This pheromone is not serving as a sex pheromone because nymphs were affected by it and because this population of H. cumberlandicus is parthenogenic. The conclusion of this study is that the biological value of the aggregation pheromone is to concentrate H. cumberlandicus in sheltered sites in the cave conducive for minimizing water stress. Rather than signaling H. cumberlandicus presence and quality, the reduced mobility expressed as a result of contacting this pheromone conceivably may act as a defense tactic (antipredator behavior) against M. ovalis, which shares this favored habitat site.

Expression monitoring by hybridization to high-density oligonucleotide arrays.

The human genome encodes approximately 100,000 different genes, and at least partial sequence information for nearly all will be available soon. Sequence information alone, however, is insufficient for a full understanding of gene function, expression, regulation, and splice-site variation. Because cellular processes are governed by the repertoire of expressed genes, and the levels and timing of expression, it is important to have experimental tools for the direct monitoring of large numbers of mRNAs in parallel. We have developed an approach that is based on hybridization to small, high-density arrays containing tens of thousands of synthetic oligonucleotides. The arrays are designed based on sequence information alone and are synthesized in situ using a combination of photolithography and oligonucleotide chemistry. RNAs present at a frequency of 1:300,000 are unambiguously detected, and detection is quantitative over more than three orders of magnitude. This approach provides a way to use directly the growing body of sequence information for highly parallel experimental investigations. Because of the combinatorial nature of the chemistry and the ability to synthesize small arrays containing hundreds of thousands of specifically chosen oligonucleotides, the method is readily scalable to the simultaneous monitoring of tens of thousands of genes.

Antitumor effects of interferon-omega: in vivo therapy of human tumor xenografts in nude mice.

The antitumor effect of the type I IFN, IFN-omega, was evaluated in both in vitro and in vivo studies of human cancer. For these studies, the cDNA for human IFN-omega was cloned into a eukaryotic expression plasmid DNA (pDNA) driven by the cytomegalovirus promoter. Supernatants from UM449 cells transfected in vitro with IFN-omega pDNA had antiproliferative effects on 11 of 13 human tumor cell lines. For in vivo studies, nude mice were implanted s.c. with one of the following human tumors: NIH: OVCAR-3 ovarian carcinoma, A375 melanoma, or A431 epidermoid carcinoma. Direct intratumoral injection of 100 microg of a IFN-omega pDNA DMRIE/DOPE complex (1:1 DNA:DMRIE mass ratio) for 6 consecutive days resulted in a significant reduction in the tumor volume of NIH: OVCAR-3 ovarian carcinoma or A375 melanoma (P = 0.02). IFN-omega pDNA delivered by i.m. injection also had an antitumor effect. Nude mice bearing s.c. A431 epidermoid carcinoma and injected i.m. with 100 microg of IFN-omega pDNA, twice per week for 3 weeks, had a significant reduction in tumor volume (P = 0.009). These results demonstrate for the first time that IFN-omega can have in vivo antitumor effects in several models of human cancer.

A validated web-based tool to display individualised Crohn's disease predicted outcomes based on clinical, serologic and genetic variables.

BACKGROUND: Early treatment for Crohn's disease (CD) with immunomodulators and/or anti-TNF agents improves outcomes in comparison to a slower 'step up' algorithm. However, there remains a limited ability to identify those who would benefit most from early intensive therapy. AIM: To develop a validated, individualised, web-based tool for patients and clinicians to visualise individualised risks for developing Crohn's disease complications. METHODS: A well-characterised cohort of adult patients with CD was analysed. Available data included: demographics; clinical characteristics; serologic immune responses; NOD2 status; time from diagnosis to complication; and medication exposure. Cox proportional analyses were performed to model the probability of developing a CD complication over time. The Cox model was validated externally in two independent CD cohorts. Using system dynamics analysis (SDA), these results were transformed into a simple graphical web-based display to show patients their individualised probability of developing a complication over a 3-year period. RESULTS: Two hundered and forty three CD patients were included in the final model of which 142 experienced a complication. Significant variables in the multivariate Cox model included small bowel disease (HR 2.12, CI 1.05-4.29), left colonic disease (HR 0.73, CI 0.49-1.09), perianal disease (HR 4.12, CI 1.01-16.88), ASCA (HR 1.35, CI 1.16-1.58), Cbir (HR 1.29, CI 1.07-1.55), ANCA (HR 0.77, CI 0.62-0.95), and the NOD2 frameshift mutation/SNP13 (HR 2.13, CI 1.33-3.40). The Harrell's C (concordance index for predictive accuracy of the model) = 0.73. When applied to the two external validation cohorts (adult n = 109, pediatric n = 392), the concordance index was 0.73 and 0.75, respectively, for adult and pediatric patients. CONCLUSIONS: A validated, web-based tool has been developed to display an individualised predicted outcome for adult patients with Crohn's disease based on clinical, serologic and genetic variables. This tool can be used to help providers and patients make personalised decisions about treatment options.

Sequence analysis of a cDNA encoding a human nuclear pore complex protein, hnup153.

Nuclear pore complexes represent the channels for the the bi-directional movement of macromolecules between the nucleus and cytoplasm, and are thought to contain upwards of 100 different polypeptide subunits. Many of these subunits belong to a growing family of polypeptides termed nucleoporins which are characterized by the presence of O-linked N-acetylglucosamine moieties and a distinctive pentapeptide repeat (XFXFG). This paper reports the primary structure of hnup153, the human homologue of the rat nucleoporin, nup153, with which it shares 82% amino acid identity. In addition to 33 copies of the XFXFG repeat, hnup153 exhibits four repeats of 37-38 amino acids each containing an apparent 'zinc finger motif'. These zinc fingers are most closely related to those found in the mouse oncoprotein mdm-2 and a product of Drosophila small optic lobes (sol) gene.

Enzymatic enhancement of the catalytic rate of sulfhydryl oxidase.

The rate of oxidation of glutathione by solubilized sulfhydryl oxidase was significantly enhanced in the presence of horseradish peroxidase (donor:hydrogen-peroxide oxidoreductase, EC 1.11.1.7). This enhancement was proportional to the amount of active peroxidase in the assay, but could not be attributed solely to the oxidation of glutathione catalyzed by the peroxidase. A change in the Soret region of the horseradish peroxidase spectrum was observed when both glutathione and peroxidase were present. Moreover, addition of glutathione to a sulfhydryl oxidase/horseradish peroxidase mixture resulted in a rapid shift of the absorbance maximum from 403 nm to 417 nm. This shift indicates the oxidation of horseradish peroxidase. Spectra for three isozyme preparations of horseradish peroxidase, two acidic and one basic, all underwent this red-shift in the presence of sulfhydryl oxidase and glutathione. Cysteine and N-acetylcysteine could replace glutathione. Addition of catalase had no effect on the oxidation of peroxidase, indicating that the peroxide involved in the reaction was not derived from that released into the bulk solution by sulfhydryl oxidase-catalyzed thiol oxidation. Further evidence for a direct transfer of the hydrogen peroxide moiety was obtained by addition of glutaraldehyde to a sulfhydryl oxidase/horseradish peroxidase/N-acetylcysteine mixture. Size exclusion chromatography revealed the formation of a high-molecular-weight species with peroxidase activity, which was completely resolved from native horseradish peroxidase. Formation of this species was absolutely dependent on the presence of both the cysteine-containing substrate and sulfhydryl oxidase. The observed enhancement of sulfhydryl oxidase catalytic activity by the addition of horseradish peroxidase supports a bi uni ping-pong mechanism proposed previously for sulfhydryl oxidase.

Glycylglycyl-L-cysteine as a substrate for renal sulfhydryl oxidase (glutathione oxidase).

Covalent chromatographically isolated bovine kidney sulfhydryl oxidase was found to catalyze the oxidation of cysteine and cysteine-containing substrates as determined by assaying with 5,5'-dithiobis(2-nitrobenzoate). Monitoring the time-course of substrate disappearance and product formation by means of high-pressure liquid chromatography revealed that such partially purified renal sulfhydryl oxidase preparations catalyze the direct oxidation of glycylglycyl-L-cysteine to its disulfide form with no other detectable metabolic products. Accordingly, Gly-Gly-Cys appears to be better suited for routine assays of sulfhydryl oxidase activity than is the traditionally employed substrate, glutathione, whose oxidation can be initiated by gamma-glutamyltransferase-catalyzed cleavage of the gamma-peptide bond, leading to falsely 'positive' assays in the absence of sulfhydryl oxidase per se.

Gender differences in device therapy for malignant ventricular arrhythmias.

BACKGROUND: Several recent reports have suggested a gender bias in the treatment of cardiovascular disease. It is not clear whether this is true in the treatment of malignant ventricular arrhythmias. OBJECTIVES: To perform a retrospective chart review of 130 patients evaluated for malignant ventricular arrhythmias between July 1990 and June 1992. To compare baseline cardiovascular and clinical parameters and treatment modalities, including cardioverter-defibrillator implantation rates, between women and men. RESULTS: There was no significant difference in the percentage of women and men who were advised to have cardioverter-defibrillator implantation (61% vs 53%) or who underwent cardioverter-defibrillator implantation (46% vs 52%). Women had a lower incidence of coronary artery disease than men (61% vs 85%, P < .01), a lower incidence of myocardial infarction (46% vs 75%, P < .01), and a higher mean left ventricular ejection fraction (38% vs 32%, P = .02). Of patients with indications for cardioverter-defibrillator implantation, significantly more women refused a device than men (19% vs 2%, P = .01), and significantly more women were considered medically ineligible for cardioverter-defibrillator implantation despite having less severe heart disease as a group (12% vs 0%, P = .04). This resulted in significantly fewer women receiving a defibrillator than men with similar indications (18 of 26 women vs 47 of 48 men, P < .01). Of patients who received defibrillators, significantly more women received investigational devices (50%) than men (21%) (P < .05) (35% of women and 19% of men with indication for cardioverter-defibrillator implantation). In-hospital mortality was low in both groups (women, 0%; men, 4%). The 30-month mortality in patients with indications for device intervention was similar in both groups (women, 21%; men, 19%). CONCLUSIONS: No evidence of difference was found between women and men in the rates of recommendation for, or implantation of, implantable cardioverter-defibrillators. Women refused device implantation more often than men, and they may be considered medically ineligible for device implantation more than men. This combination results in fewer women with medical indications for cardioverter-defibrillator implantation receiving defibrillators than men. This difference does not appear to be associated with increased short-term mortality.

Assessment of gene regulation by bone morphogenetic protein 2 in human marrow stromal cells using gene array technology.

Marrow stromal cells can differentiate into osteoblasts, adipocytes, myoblasts, and chondrocytes. Bone morphogenetic protein 2 (BMP-2) is a potent stimulator of osteoblastic differentiation, and identification of the genes regulated by BMP-2 in these cells should provide insight into the mechanism(s) of osteoblastic differentiation. Thus, we used a conditionally immortalized human marrow stromal cell line (hMS) and a gene expression microarray containing probes for a total of 6800 genes to compare gene expression in control and BMP-2-treated cultures. A total of 51 genes showed a consistent change in messenger RNA (mRNA) frequency between two repeat experiments. Seventeen of these genes showed a change in expression of at least 3-fold in BMP-2-treated cultures over control cultures. These included nuclear binding factors (10 genes), signal transduction pathway genes (2 genes), molecular transport (1 gene), cell surface proteins (2 genes) and growth factors (2 genes). Of particular interest were four of the nuclear binding factor genes ID-1, ID-2, ID-3, and ID-4. These encode dominant negative helix-loop-helix (dnHLH) proteins that lack the nuclear binding domain of the basic HLH proteins and thus have no transcriptional activity. They have been implicated in blocking both myogenesis and adipogenesis. Other transcription factors up-regulated at least 3-fold by BMP-2 included Dlx-2, HES-1, STAT1, and JunB. The changes in these nuclear binding factor mRNA levels were confirmed by real-time reverse-transcriptase-polymerase chain reaction (RT-PCR). A further three transcription factors, core binding factor beta (CBFbeta), AREB6, and SOX4, showed changes in expression of between 2- and 3-fold with BMP-2 treatment. In summary, we have used a gene chip microarray to identify a number of BMP-2 responsive genes in hMS cells. Thus, these studies provide potential candidate genes that may induce osteoblastic differentiation or, in the case of the ID proteins, block differentiation along alternate pathways.

Independent expression and assembly properties of heterologous lamins A and C in murine embryonal carcinomas.

The majority of cells derived from adult mammalian tissues contain three major species of nuclear lamin proteins, A, B and C. In contrast, embryonic cells including undifferentiated murine embryonal carcinomas, contain only B-type lamins, A and C appearing only after differentiation. Human lamins A or C have been introduced by transfection into undifferentiated P19 embryonal carcinomas. Twenty-four hours after transfection, both of these proteins were found to independently associate with the nuclear envelope as judged by immunofluorescence microscopy and at the same time were associated with a salt-resistant structure having solubility properties similar to those of the nuclear lamina. Biosynthetic experiments indicated that heterologous lamin A underwent processing to its mature molecular weight, an event which in adult type cells occurs after assembly into the lamina. Observations on mitotic cells demonstrate that either of the two human lamins will, independent of the other, become dispersed throughout the cytoplasm during prophase and subsequently reassemble at the nuclear periphery during telophase. Nuclear lamins A and C are not, however, equivalent in their abilities to incorporate into the nuclear lamina in these cells. Experiments involving cells arrested in S phase using thymidine suggest that lamin C, but not lamin A, requires progression through the cell cycle and probably mitosis for assembly into the nuclear lamina of P19 EC cells.

Immunotherapy of established tumors in mice by intratumoral injection of interleukin-2 plasmid DNA: induction of CD8+ T-cell immunity.

Intratumoral (i.t.) injection of a plasmid DNA vector encoding the murine interleukin-2 (IL-2) gene was used to treat established renal cell carcinoma (Renca) tumors in BALB/c mice. Tumor regression was observed in 60-90% of mice that were injected i.t. for 4 days with IL-2 plasmid DNA complexed with the cationic lipid DMRIE/DOPE ((+/-)-N-(2-hydroxyethyl)-N,N-dimethyl-2,3-bis(tetradecyloxy)-1-propa naminium bromide/dioleoylphosphatidylethanolamine). The mice remained tumor-free until the conclusion of the study, which was 4 months after tumor challenge. In a rechallenge experiment, mice that were rendered tumor-free for 6 months by IL-2 plasmid DNA treatment rejected a subsequent challenge of Renca cells but could not reject a challenge with the unrelated, syngeneic CT-26 tumor. Spleen cells from cured mice contained Renca-specific cytotoxic T lymphocytes, and adoptive transfer of mixed lymphocyte cultures into naive mice at 2 days after challenge with Renca cells prevented tumor growth. In vivo depletion of T-cell subsets at the time of i.t. injection with IL-2 plasmid DNA demonstrated that CD8+ T cells, but not CD4+ T cells, were the primary effectors of the antitumor response.

Technology evaluation: interleukin-2 gene therapy for the treatment of renal cell carcinoma.

Leuvectin is a plasmid DNA/lipid complex comprised of a plasmid DNA expression vector (VCL-1102, 30) encoding human interleukin (IL)-2 complexed in a 5:1 mass ratio with DMRIE/DOPE lipid that has been developed for the treatment of cancer. DMRIE/DOPE is a cationic lipid, which facilitates in vitro and in vivo transfection of plasmid DNA. In vitro transfection with the IL-2 plasmid DNA/DMRIE/DOPE complex results in the expression of sustained levels of biologically active IL-2. Human tumor cell lines and primary human tumor cells established from biopsies were readily transfected in vitro resulting in the expression of IL-2. Following in vitro transfection, IL-2 expression continued up to several weeks post-transfection in primary tumor cells. In preclinical efficacy studies in a murine model of renal cell carcinoma (RCC), the direct intratumoral administration of an IL-2 plasmid DNA/DMRIE/DOPE complex resulted in the generation of tumor specific lymphocytes and complete tumor regression in the majority of the mice. In preclinical animal safety studies, repeated administration of Leuvectin was safe and well-tolerated. Following these promising preclinical results, Leuvectin has entered clinical trials and two pilot phase I/II trials are described.

Dissecting the marrow microenvironment.

Cloned human stromal cell lines representing functionally distinct cellular components of the marrow microenvironment were generated to serve as tools for identifying gene products that regulate hematopoiesis. Oligonucleotide arrays, or "gene chips" were used to provide a comprehensive comparison of gene expression among the cell lines. One line, designated HS-5, was found to secrete large amounts of cytokines, and conditioned media from this line was found to support the ex vivo expansion of both immature and mature progenitors. In contrast, a second line, designated HS-27a, does not secrete known cytokines but does support cobblestone area formation by CD34+/38lo cells. HS-27a, but not HS-5, was also found to express hJagged1, a ligand for Notch1, which may function to influence cell fate decisions of hematopoietic precursors. Both cell lines are currently being used to identify other gene products that regulate hematopoiesis and to generate reagents that will allow more formal evaluation of the putative role of hJagged1 in hematopoietic cell fate decisions.

The use of polymerase chain reaction and shortwave UV irradiation to detect baculovirus DNA on the surface of gypsy moth eggs.

Polymerase chain reaction (PCR) technology was employed to detect baculovirus DNA sequences from viral occlusion bodies (OB) contaminating the surface of gypsy moth eggs. The level of sensitivity of the technique was as low as 5 viral genome copies and DNA from 1 OB equivalent. Thirty minutes of shortwave UV irradiation of eggs contaminated with 8.4 x 10(4) OBs prevented amplification of viral DNA sequences from OBs on the egg surface. These methods are important for providing a better understanding of gypsy moth virus epizootiology as well as for the examination of insect eggs for the persistence of baculovirus gene sequences inside the egg or on the egg surface. In addition, these methods can be easily modified for monitoring the persistence of genetically engineered baculoviruses in insect populations as well as the fate of genes that these viruses might carry.

The acceptance of the collagen sponge diaphragm as an intravaginal contraceptive in human volunteers.

Two types of highly resilient and liquid-absorbent collagen sponge contraceptives (CSC) in the shape of cylindrical cups (6 cm wide and 2.5 cm thick) were evaluated for acceptance as an intravaginal contraceptive method for a period of 3 months in 27 volunteers. Parameters such as retention, odor, irritation, itching, discharge, and convenience for the user and her sexual partner were tested. Average retention time was 7 to 9 days (range, 2 to 28 days); still, most sexually active volunteers preferred to remove the CSC every 3 to 4 days, rinse them in tap water, and reinsert them. Odor was noticed by users in 4% of the tested sponges and in 30% of all volunteers by medical personnel at the time of removal of the CSC from the vagina. No irritation, itching, or discharge was reported. The CSC alone did not cause any inconvenience to the user or partner, while the CSC with inserted rubber ring was felt by both partners and was found to be dislocated. This study indicates good acceptance of the CSC in intravaginal use. Studies to evaluate the efficacy of collagen sponges as mechanical contraceptive barriers are in progress.

Systemic delivery of therapeutic proteins by intramuscular injection of plasmid DNA.

In vivo delivery of a cytokine gene to treat a tumor has usually involved either injection of ex vivo transfected cells around the tumor site or direct intratumoral injection of a virus or plasmid DNA (pDNA) vector encoding the cytokine gene (1,2). In this manner, transfected cells in or around the tumor site may secrete cytokine locally and stimulate an antitumor immune response (3,4). Recently, a new method of cytokine gene delivery for treating tumors was described. In this method, a naked pDNA encoding a cytokine, in this case, interferon-α (IFN-α), was injected intramuscularly (im) into C57BL/6 mice bearing solid or metastatic B16F10 melanoma tumors (5). The mice treated in this manner had a striking inhibition of tumor growth.