Tuberculin skin test screening practices among US colleges and universities

CONTEXT

Concern about transmission of Mycobacterium tuberculosis on college campuses has prompted some schools to institute tuberculin skin test screening of students, but this screening has never been evaluated.

OBJECTIVE

To describe tuberculin skin test screening practices and results of screening in colleges and universities in the United States.

DESIGN AND SETTING

Self-administered mail and telephone questionnaire in November and December 1995 to a stratified random sample of US 2-year and 4-year colleges and universities.

MAIN OUTCOME MEASURES

Type of tuberculin screening required; types of schools requiring screening; number and rate of students with positive skin test results and/or diagnosed as having tuberculosis.

RESULTS

Of the 3148 US colleges and universities, 624 (78%) of 796 schools surveyed responded. Overall, 378 schools (61%) required tuberculin screening; it was required for all new students (US residents and international students) in 161 (26%) of 624 schools, all new international students but not new US residents in 53 (8%), and students in specific academic programs in 294 (47%). Required screening was more likely in 4-year vs 2-year schools, schools that belonged to the American College Health Association vs nonmember schools, schools with immunization requirements vs schools without, and schools with a student health clinic vs those without (P<.001 for all). Public and private schools were equally likely to require screening (64% vs 62%; P=.21). In the 378 schools with screening requirements, tine or multiple puncture tests were accepted in 95 (25%); test results were recorded in millimeters of induration in 95 (25%); and 100 (27%) reported collecting results in a centralized registry or database. Of the 168 (27%) of 624 schools accepting only Mantoux skin tests and reporting results for school years 1992-1993 through 1995-1996, 3.1% of the 348 368 students screened had positive skin test results (median percentage positive, 0.8%). International students had a significantly higher case rate for active tuberculosis than US residents (35.2 vs 1.1 per 100000 students screened).

CONCLUSIONS

Widespread tuberculin screening of students yielded a low prevalence of skin test reactors and few tuberculosis cases. To optimize the use of limited public health resources, tuberculin screening should target students at high risk for infection.

Control of hepatitis B in the United Kingdom

Control of hepatitis B in the UK is based upon selective vaccination of persons in high-risk groups. To assess the likely cost-effectiveness of changes to this policy, information on the current burden of HBV infection in the UK is required. Laboratory reports of acute hepatitis B suggest that the vast majority of new hepatitis B infections acquired in the UK occur in adults, even after adjustment for unapparent infection. In childhood, perinatal transmission remains the most significant known risk factor. Universal antenatal screening has the potential to prevent perinatal infections in UK births and a substantial proportion of those UK acquired infections which lead to carriage. In addition, to antenatal screening, universal infant vaccination (at 2, 3 and 4 months) can, in the short term, only prevent the small number of infections acquired in childhood. Economic analysis using current surveillance data is required to assess the possible cost-benefit of universal vaccination. Regardless of this, there is an urgent need to improve selective vaccination and to ensure that a high proportion of antenatal carriers is identified.

Protective cytotoxic T lymphocyte responses against paramyxoviruses induced by epitope-based DNA vaccines: involvement of IFN-gamma

Plasmid DNA vectors have been constructed with minigenes encoding a single cytotoxic T lymphocyte (CTL) epitope from either the M2 protein of respiratory syncytial virus (RSV) or from the nucleoprotein of measles virus (MV) with or without a signal sequence (also called secretory or leader sequence). Following intradermal immunization, plasmids in which the CTL epitopes were expressed in-frame with the signal sequence were more effective at inducing peptide- and virus-specific CTL responses than plasmids expressing CTL epitopes without the signal sequence. This immunization resulted in protection against MV-induced encephalitis and a significant reduction in viral load following RSV challenge. The reduction of viral load following RSV challenge was abrogated by prior injection with anti-IFN-gamma antibodies. These results highlight the ability of epitope-based DNA immunization to induce protective immune responses to well-defined epitopes and indicate the potential of this approach for the development of vaccines against infectious diseases.

Recombinant human interleukin-11 does not affect functions of purified human neutrophils in vitro

Recombinant human interleukin-11 (rHu-IL-11) is a multifunctional cytokine with thrombopoietic activity and demonstrated clinical efficacy in treating chemotherapy-induced thrombocytopenia. rHu-IL-11 also exhibits anti-inflammatory activity and is currently in clinical trials for the treatment of several inflammatory diseases. As neutrophils are involved in both innate immunity and an acute inflammatory response, the effect of rHU-IL-11 on the function of human peripheral blood neutrophils in vitro was examined. rHu-IL-11 was not cytotoxic and did not induce superoxide anion production or the release of granular enzymes from resting neutrophils. Phagocytosis and chemotaxis were unaffected. rHu-IL-11 treatment did not block the response of neutrophils to stimulation. Pretreatment with rHu-IL-11 did not reduce production of IL-8 following activation with lipopolysaccharide (LPS) or zymosan A particles. Pretreatment with rHu-IL-11 did not affect the release of lysozyme and beta-glucuronidase in response to A23187 or PMA-stimulated production of superoxide anion. These results indicate that rHu-IL-11 does not directly modulate key functions of neutrophils in vitro.

Characterization of two distinct families of transcription factors that bind to the CCAAT box region of the human COL1A2 gene

Both the mouse and human alpha2(I) procollagen promoters contain an inverted CCAAT box at -80, but only the human promoter contains an additional regulatory element, the collagen modulating element (CME), immediately downstream of the CCAAT box [Collins et al. (1997): Biochem J 322:199-206]. In this study, the transcription factors that bind to the G/CBE and CME within the human promoter were characterized in SVWI-38 and CT-1 nuclear extracts. Two distinct proteins bind to the CME, and both were identified as heat-labile factors that were sensitive to high ionic strengths and required Zn2+ for DNA-binding activity. These proteins had Stokes radii of 4.12 and 3.15 nm, sedimentation coefficients of 3.9 and 3.2 S and native molecular weights of 66 and 41 kDa, respectively. On the basis of biochemical and DNA-binding properties, the CME binding proteins are probably novel factors involved in the regulation of the human alpha2(I) procollagen gene. By contrast, the G/CBE binding proteins were more resistant to heat, ionic strength, and divalent metal ion chelators, demonstrating that the G/CBE and CME binding proteins had distinct DNA-binding properties. The above properties suggest that this factor is a member of the previously characterized family of CCAAT box-binding factors, CBF, NF-Y, CP-1 and alpha-CP1. Taken together, these physicochemical properties of the COL1A2 CCAAT box and CME-binding proteins demonstrated that they were distinct unrelated transcription factors. These results also suggest that there is a distinct difference in the DNA-binding activity between the equivalent region of the mouse and human alpha2(I) procollagen promoters.

The murine IL-13 receptor alpha 2: molecular cloning, characterization, and comparison with murine IL-13 receptor alpha 1

Two components of a receptor complex for IL-13, the IL-4R and a low affinity IL-13-binding chain, IL-13R alpha 1, have been cloned in mice and humans. An additional high affinity binding chain for IL-13, IL-13R alpha 2, has been described in humans. We isolated a cDNA from the thymus that encodes the murine orthologue of the human IL-13R alpha 2. The predicted protein sequence of murine IL-13R alpha 2 (mIL-13R alpha 2) has 59% overall identity to human IL-13R alpha 2 and is closely related to the murine low affinity IL-13-binding subunit, IL-13R alpha 1. The genes for both mIL-13-binding chains map to the X chromosome. A specific interaction between mIL-13R alpha 2.Fc protein and IL-13 was demonstrated by surface plasmon resonance using a BIACORE instrument. Ba/F3 cells that were transfected with mIL-13R alpha 2 expressed 5000 molecules per cell and bound IL-13 with a single Kd of 0.5 to 1.2 nM. However, these cells did not proliferate in response to IL-13, and the IL-4 dose response was unaffected by high concentrations of IL-13. In contrast, the expression of mIL-13R alpha 1 by Ba/F3 cells resulted in a sensitive proliferative response to IL-13. Consistent with its lower affinity for IL-13, IL-13R alpha 1.Fc was 100-fold less effective than IL-13R alpha 2.Fc in neutralizing IL-13 in vitro. These results show that mIL-13R alpha 2 and mIL-13R alpha 1 are not functionally equivalent and predict distinct roles for each polypeptide in IL-13R complex formation and in the modulation of IL-13 signal transduction.

A far upstream, cell type-specific enhancer of the mouse thrombospondin 3 gene is located within intron 6 of the adjacent metaxin gene

Thrombospondin 3 (TSP3) is a secreted, pentameric glycoprotein whose regulation of expression and function are not well understood. Mouse Thbs3 is located just downstream from the divergently transcribed metaxin gene (Mtx), which encodes an outer mitochondrial membrane import protein. Although Thbs3 and Mtx share a common promoter region, previous studies showed that Mtx is regulated by proximal elements that had little effect on Thbs3 expression. In this study, transient transfection of rat chondrosarcoma cells and NIH-3T3 fibroblasts demonstrated that Thbs3 is regulated in a cell type-specific manner by a position- and orientation-independent far upstream enhancer located within intron 6 of Mtx. Despite its greater proximity to the transcription start site of Mtx, the Thbs3 enhancer did not have a significant effect on Mtx expression. Two DNA-protein complexes, which were both required for activity, were identified when nuclear extracts were assayed with a probe containing the enhancer sequence. The protein in one of these complexes was identified as Sp1, while the other DNA-protein complex remains uncharacterized. A 6-kilobase pair promoter containing the enhancer was able to direct specific expression of the E. coli lacZ gene in transgenic mice, whereas a 2-kilobase pair promoter that lacked the enhancer was inactive. Thus, despite their close proximity, the genes of the Mtx/Thbs3 gene cluster are regulated independently.

Interhemispheric communication is via direct connections

Two priming experiments, using normal university students as subjects, independently projected low imagery primes and concrete target words to the left or right visual fields (LVF or RVF) to examine the merits of three spreading activation models of interhemispheric communication: (i) callosal relay of a semantically encoded prime; (ii) transfer of products activated as a result of the spread of activation; and (iii) direct connections between the hemispheres. The first experiment temporally separated pairs by a stimulus onset asynchrony (SOA) of 250 ms and obtained strong support for the direct connections model. Priming effects were obtained only when the prime was projected to the RVF and the target to the LVF. The pattern of priming effects suggested that low imagery words projected to the left hemisphere can activate concrete associates in the right hemisphere via direct callosal connections between the two. In the second experiment, the SOA was increased to 450 ms. This time, RVF-RVF priming was obtained along with RVF-LVF priming. The findings are interpreted within a modification of Bleasdale's (1987) framework, where abstract/low imagery words and concrete/high imagery words are represented in separate subsystems in the left hemisphere lexicon. Support was also found for the view that the left hemisphere is comprised of a complex network of abstract and concrete words, while the right hemisphere operates as a subsidiary word processor, subserving linguistic processing with a limited, special purpose lexicon comprised of associative connections between concrete, imageable words (e.g., Zaidel, 1983a; Bradshaw, 1980). Interhemispheric communication in the priming procedure appears to occur at the semantic level, via direct connections between the hemispheres.

Increasing self-efficacy through empowerment: preoperative education for orthopaedic patients

PURPOSE

To examine whether patients who received an empowerment model of education for preoperative orthopaedic teaching had improved outcomes compared to patients who received the traditional education.

DESIGN

An experimental (empowerment teaching method) group vs. comparison (traditional teaching method) group posttest design.

SAMPLE

Seventy-four patients undergoing elective orthopaedic surgery.

METHODS

Following the preoperative teaching session, patients in both groups completed a questionnaire designed to measure their perceptions of the teaching (empowerment) and self-efficacy (belief in their ability to carry out perioperative tasks). A chart audit and phone interview was done after discharge to assess length of stay, pain management, complications, and patient perceptions of the ability to complete perioperative tasks.

FINDINGS

Patients in the empowerment group felt the educational approach was more empowering and had significantly higher self-efficacy scores than those in the traditional teaching group. There was much less variation in empowerment and self-efficacy scores in the empowerment group. The empowerment group reported feeling greater confidence in performing perioperative tasks. There were no differences in length of stay, complications or pain control.

CONCLUSION

Use of an empowerment teaching approach enabled patients to become more confident in their ability to carry out perioperative tasks and become a more integral part of the preoperative teaching process.

IMPLICATIONS FOR NURSING RESEARCH

The theoretical model will be used to structure other educational programs and guide research. More sensitive measures of complications and pain control should be considered for future studies.

Clinical safety of oral sildenafil citrate (VIAGRA) in the treatment of erectile dysfunction

Sildenafil citrate has been shown to be effective in a wide range of patients with erectile dysfunction and has been approved in the United States for this indication. The overall clinical safety of oral sildenafil, a potent inhibitor of phosphodiesterase type 5, in the treatment of erectile dysfunction was evaluated in more than 3700 patients (with a total of 1631 years of exposure worldwide). Safety and tolerability data were analysed from a series of double-blind, placebo-controlled studies and from 10 open-label extension studies of sildenafil in the treatment of erectile dysfunction. A total of 4274 patients (2722 sildenafil, 1552 placebo; age range 19-87 y) received double-blind treatment over a period of up to six months' duration, and 2199 received long-term, open-label sildenafil for up to 1 y. The most commonly reported adverse events (all causes) were headache (16% sildenafil, 4% placebo), flushing (10% sildenafil, 1% placebo), and dyspepsia (7% sildenafil, 2% placebo) and they were predominantly transient and mild or moderate in nature. These adverse events reflect the pharmacology of sildenafil as a phosphodiesterase type 5 inhibitor. No cases of priapism were reported. The rate of discontinuation due to adverse events (all causes) was comparable for patients treated with sildenafil (2.5%) and placebo (2.3%). In open-label extension studies, 90% of patients completed long-term sildenafil treatment, with only 2% withdrawing due to adverse events. Sildenafil is a well-tolerated oral treatment for erectile dysfunction.

Laboratory surveillance of hepatitis C virus infection in England and Wales: 1992 to 1996

Screening assay for antibody to hepatitis C virus (HCV) became available late in 1990 and their use has subsequently become widespread. Laboratories in England and Wales reported 5232 confirmed HCV infections to the PHLS Communicable Disease Surveillance Centre (CDSC) between 1992 and 1996. Fifty-seven per cent (2976) of reports included risk factor information, 80% of which (2382) identified injecting drug use as the main route of transmission. Thirty-one per cent of reports (1640) included clinical information: 41% (665) were asymptomatic, 57% (938) had symptoms, signs, or biochemical abnormalities of hepatic origin, and 2.2% (37) had non-hepatic conditions. To enhance these data two additional surveys have been undertaken to collect data on all anti-HCV tests performed in public health laboratories. In 1993, a retrospective survey of people tested between 1990 and 1993 revealed that the prevalence of antibody was highest (222/331 [67%]) among injecting drug users and recipients of blood or blood products (189/548 [34%]) and lower among other groups. In a prospective survey of HCV tests performed in transfusion recipients in early 1995, the prevalence of antibody was higher in those transfused before 1985 (11/418 [2.6%]) than in those transfused after 1985 (14/1441 [1.0%]). Reports of confirmed infections are a useful method of monitoring hepatitis C infection but additional data on testing are needed to interpret trends overall and in specific risk groups.

Obstetrician-gynecologists as primary care physicians: the Oregon experience--early perceptions regarding the effects of legislative action

OBJECTIVE

Our purpose was to assess whether legislative action influenced the role of obstetrician-gynecologists as primary care physicians.

STUDY DESIGN

An observational study was performed on the basis of a questionnaire sent to 410 obstetrician-gynecologists and 27 medical directors of managed-care organizations.

RESULTS

Of 67% of obstetrician-gynecologists and 96% of medical directors who responded, there was agreement as to the content of primary care, but a minority (38%) of obstetrician-gynecologists identified themselves as primary care providers. A minority of medical directors (35%) felt that obstetrician-gynecologists should serve in that role. Both obstetrician-gynecologists and medical directors felt that legislation had little impact.

CONCLUSION

The reticence of obstetrician-gynecologists to assume a major role in primary care appears to be the result of an uneasiness with accepting a more comprehensive role in patient management and gatekeeping. They appear comfortable with the more traditional roles but feel that training and experience has not prepared them well for the management of more complex medical problems.

Alveolar bone grafting: a review of 115 patients

The results of alveolar bone grafting carried out at The Hospital for Sick Children, Great Ormond Street, London, UK, between January 1982 and January 1989 were assessed. Cancellous bone from the iliac crest was grafted to alveolar cleft defects in 115 patients (63 male and 52 female). Eighty-seven unilateral (58 left and 29 right) and 28 bilateral clefts were operated on. The mean age at the time of operation was 11.5 years, with a range of 8.08-18.75 years. The cleft canine had erupted prior to bone grafting in 58.4 per cent. At the time of this study the cleft had erupted in 96.35 per cent and was unerupted in 3.65 per cent of sites. Radiographs were taken at regular intervals and assessed according to previously reported criteria. Eighty-six per cent were clinically successful (Type I and II). In Type III 10.95 per cent had less than three-quarters of the normal interdental septal height and 2.18 per cent failed (Type IV). In addition, 3.6 per cent of sites showed cervical root resorption affecting the adjacent incisor and 1.4 per cent internal resorption of the cleft canine.

Masking of irregular corneal topography with contact lenses

PURPOSE

We examined the effectiveness of various types of contact lenses in masking irregular corneal topography using videokeratoscopy, residual aberrations, and measurement of visual acuity.

METHODS

Thirteen subjects with differing degrees of keratoconus were recruited. Four types of soft lenses were used that varied in both thickness and water content, along with a rigid gas permeable (RGP) and a flexible gas permeable contact lens.

RESULTS

RGP contact lenses provided the best visual acuity and the least residual aberrations. Flexible gas permeable lenses showed a reasonable masking of corneal distortion but did not provide the expected improvement in visual acuity. Soft contact lenses provided marginally better visual acuity than spectacle correction, but the level of residual aberrations was still high, even for relatively thick soft lenses (up to 0.2 mm). A significant correlation existed between the regularity of the front surface of the contact lenses on the eye and visual acuity in low illumination.

CONCLUSIONS

Among the currently available contact lens materials, RGP lenses provide the best visual performance for subjects with keratoconus.

Retroviral vector targeting to melanoma cells by single-chain antibody incorporation in envelope

Two strategies for targeting recombinant retroviruses to melanoma cells were compared. One was to extend the tropism of an ecotropic envelope to human melanoma cells, the other was to enhance the tropism of an amphotropic envelope for melanoma cells. Chimeric retroviral envelopes, incorporating a single-chain antibody (ScFv) directed against high-molecular-weight melanoma-associated antigen (HMWMAA) at the amino terminus are correctly processed and incorporated into virions. ScFv-ecotropic envelope chimeras allow specific, but low-titer, targeting of HMWMAA-positive cells, when co-expressed with ecotropic envelopes. ScFv-amphotropic envelope chimeras bind specifically to HMWMAA-positive cells and allow preferential infection at high titer.

Quantitation of hepatitis G and C viruses in the liver: evidence that hepatitis G virus is not hepatotropic

Hepatitis G virus (HGV) is prevalent in patients with chronic liver disease and has been previously detected in liver specimens. However, it is unknown whether the virus is replicating in the liver or is simply a contaminant from serum. We sought to determine whether HGV was hepatotropic and to determine whether coinfection with HGV and hepatitis C virus (HCV) influenced the level of either virus. Virus was quantitated using branched DNA (bDNA) assay for both HGV and HCV in the liver explants and pretransplant serum samples from 30 transplant recipients: Group I, HGV/HCV coinfection (n = 10); group II, HCV infection alone, (n = 8); group III, HGV alone (n = 12). In patients with coinfection HCV (RNA) titers in liver were consistently higher than those for HGV RNA (median 1.13 x 10(8) and 360,000 Eq/g respectively, P < .01). The ratio of liver/serum viral RNA was significantly higher for HCV than for HGV (median 129 and 0.3 respectively, P < .01). Levels of HCV RNA were similar in patients with HCV infection alone versus those with HGV/HCV coinfection (median; liver = 1.15 x 10(7) vs. 1.13 x 10(8) Eq/g, serum = 500,000 vs. 200,000 Eq/mL) and levels of HGV RNA in liver and serum were similar in patients with HGV infection alone compared to those with HGV/HCV coinfection (median; liver = 1.2 x 10(6) vs. 4.0 x 10(5) Eq/g, serum = 4.5 x 106 vs. 2.6 x 10(6) Eq/mL). Levels of either virus appeared unaffected by the presence of an additional virus. The high ratio of HCV RNA levels in liver compared to serum is consistent with its known hepatotropism, but this pattern was not observed for HGV. The median liver/serum ratio of HGV RNA was less than unity, a finding consistent with serum contamination of liver tissue. Thus we conclude that the liver is not the main site of HGV replication.