A novel gel-based method for self-collection and ambient temperature postal transport of urine for PCR detection of Chlamydia trachomatis

OBJECTIVES

The aim of this study was to develop a novel urine transport method to be used in self-collection-based screening for Chlamydia trachomatis. The method needed to be suitable for C trachomatis PCR detection, be economical and suitable for transport by standard envelope mailing.

METHODS

An anhydrous gel composed of super-absorbent polymer and buffering agent was used to desiccate urine into a dry granulous state, which could subsequently be reconstituted upon arrival at a laboratory. DNA was then extracted from the reconstituted solution using the Roche MagNA Pure protocol for the detection of C trachomatis by PCR. Collections of urine specimens from three populations with widely differing chlamydia prevalence (100%,n = 56; 47%, n = 70; 3%, n = 97) were used. We determined the gel method's impact on C trachomatis PCR sensitivity and specificity using neat and gel-processed urine specimens. An equine herpes virus PCR was used to test for assay inhibition.

RESULTS

Overall, the sensitivity of the gel-based method ranged from 94.6-100% compared with neat urine, with a specificity of 100%. No PCR inhibition or decrease in analytical sensitivity was observed using the gel-processed extracts.

CONCLUSIONS

The gel-based method was found to be suitable for the detection of C trachomatis by PCR. In addition, its ease of use, effectiveness at ambient temperature and low cost makes it well-suited for self-collection kits used in population-based C trachomatis screening, particularly for geographically and socially isolated individuals.

Posttreatment follow-up of Helicobacter pylori infection using a stool antigen immunoassay

The Helicobacter pylori stool antigen enzyme immunoassay (HpSA) was evaluated during posttreatment follow-up of patients in a country with a very high prevalence of H. pylori infection. From among 273 dyspeptic individuals (18 to 55 years) initially recruited from a shantytown in Lima, Peru, 238 participants who met the inclusion criteria and were suspected to be H. pylori positive based on (14)C urea breath test (UBT) results underwent endoscopy. Participants with endoscopy-proven infections received standard eradication therapy and were monitored by UBT and HpSA at 1 month following treatment and at 3-month intervals for 9 months posttreatment. A second endoscopy was performed if UBT results showed evidence of treatment failure or H. pylori recurrence. Biopsy results were considered the "gold standard" in all analyses. Among patients who underwent endoscopy, HpSA had a pretreatment sensitivity of 93%. Two-hundred thirty patients completed the treatment regimen, of whom 201 (93%) were considered to have had successful treatment outcomes based on a negative follow-up UBT. Thirty-two patients with UBT-defined treatment failures or H. pylori recurrences at any point during the 9-month follow-up underwent a second endoscopy. In the posttreatment setting, HpSA had an overall sensitivity of 73% and a specificity of 67%. Agreement between UBT and HpSA diminished throughout the follow-up. Among 14 participants in whom HpSA remained positive at 1 month following treatment despite UBT evidence of treatment success, 12 (86%) became HpSA negative within 3 months posttreatment. Although this study confirmed the validity of the HpSA in the initial assessment of dyspeptic patients, the test demonstrated a reduced overall accuracy in the detection of treatment failures and H. pylori recurrences during 9 months of posttreatment follow-up. Furthermore, in some patients it may take up to 3 months after successful eradication for antigen shedding to diminish to levels within the negative HpSA range.

Two-year study of the protective efficacy of the oral whole cell plus recombinant B subunit cholera vaccine in Peru

The protective efficacy of an oral inactivated whole cell Vibrio cholerae plus recombinant B subunit cholera vaccine was determined against El Tor cholera among Peruvian children and adults (2-65 years old) in a randomized, double-blind manner. Study subjects received 2 doses of vaccine or placebo 2 weeks apart, followed by a booster dose 10 months later. Surveillance for cholera was performed actively, with 2 visits per week to each household, and passively, at a local hospital. Stool samples were collected during diarrhea episodes and were cultured for V. cholerae. A total of 17,799 persons received 2 doses of vaccine or placebo, and 14,997 of these persons received the booster dose. After 2 doses (first surveillance period), V. cholerae biotype O1 was isolated from 17 vaccinees and 16 placebo recipients, demonstrating vaccine efficacy (VE) of -4%. After 3 doses (second surveillance period), V. cholerae O1 was isolated from 13 vaccinees and 32 placebo recipients, demonstrating VE of 61% (95% confidence interval ¿CI, 28%-79%). In the second surveillance period, the VE for illness requiring hospitalization was 82% (95% CI, 27%-96%). VE was also higher for persons >15 years old (VE, 72%; 95% CI, 28%-89%).

Magnesium and carbonate in enamel and synthetic apatites

This study aimed to: determine the Mg and CO3 distribution in the outer (surface), middle, and inner (closest to the enamel-dentin junction, EDJ) layers of human enamel; and determine the factors affecting the incorporation of Mg into synthetic apatites and the consequence of such incorporation on the properties of the apatites. Results demonstrated that the concentrations of Mg, CO3, and organic components increased from the surface to the inner layers close to the EDJ and a difference in crystallinity from the outer to the inner layers. Initial results indicated that the extent of dissolution of the inner layer enamel is greater than that in the outer or surface enamel. Results on synthetic apatites showed the following: (1) Limited Mg incorporation into apatite was dependent on solution [Mg/Ca] molar ratio, temperature, pH, and the presence of CO3 or fluoride (F); (2) incorporation of Mg causes reduction in crystallinity and an increase in the extent of dissolution of the apatite; (3) the negative effect of Mg on the properties of apatites is synergistic to that of CO3 and antagonistic to that of F; and (4) exposure to acid of Mg-containing apatites causes the dissolution of Mg-rich apatite and precipitation of Mg-poor apatite. The observed decrease in the [Mg/Ca] of enamel and synthetic apatites after acid exposure may explain the observed 'preferential loss' of Mg and CO3 in the initial stages of caries.

Monoclonal antibodies directed against the amino-terminal domain of human TBP cross-react with TBP from other species

The TATA box-binding protein (TBP) is a key transcription factor required for transcription by all three eukaryotic RNA polymerases. It consists of a conserved carboxy-terminal DNA binding domain and a highly divergent amino terminal domain. TBP and different sets of TBP-associated factors (TAFs) constitute at least four multisubunit complexes referred to as SL1, TFIID, TFIIIB, and SNAPC. SL1, TFIID, and TFIIIB are required for transcription by RNA polymerases I, II, and III, respectively, while the SNAP complex is involved in transcription of the small nuclear RNA (snRNA) genes by RNA polymerases II and III. TBP also associates with a number of basal transcription factors such as TFIIA and TFIIB, and with several regulatory factors such as VP16, E1A, and p53. Here we describe the characterization of a panel of monoclonal antibodies (MAbs) directed against the amino-terminal domain of human TBP. These MAbs recognize different TBP epitopes, some of which have been precisely defined. Different MAbs recognize different TBP-containing complexes and several of them crossreact with TBP from other species. These antibodies can be used to purify TBP-containing complexes in a functional form and should be useful to identify new protein-protein interactions involving TBP.

Enhancing research utilization by clinical nurse specialists

A research utilization forum for clinical nurse specialists was initiated in the early 1990s in two service settings. The primary purpose of this voluntary, small-group strategy was to help master's-prepared clinicians gain knowledge and skills regarding the systematic use of research findings. This article describes the forum strategy and its conceptual base. It also reviews outcomes related to program objectives, utilization competencies, and case reports of subsequent clinical nurse specialist research utilization behavior.

Synergistic effects of magnesium and carbonate on properties of biological and synthetic apatites

Magnesium (Mg) and carbonate (CO3) are minor elements associated with enamel, dentin and bone apatite. The purpose of this study was to determine the effect of Mg and CO3 on some properties of synthetic apatites to gain insights on their effects on biological apatites. Biological apatites from human enamel and dentin and from bovine bone and synthetic apatites with/without Mg or CO3 were characterized using x-ray diffraction, infrared absorption, thermogravimetry and chemical analyses. Dissolution in acidic buffer was also determined. Results from this study demonstrated: (1) the synergistic effects of Mg and CO3 on reducing the crystallinity and increasing the extent of dissolution of synthetic apatites; (2) dentin and bone, compared to enamel apatite contained higher levels of Mg and CO3; had lower crystallinity and higher extent of dissolution. The lower crystallinity and higher extent of dissolution of dentin and bone compared to enamel apatite may be partly attributed to their higher Mg and CO3 concentrations.

Intracranial aneurysms: size, risk of rupture, and prophylactic surgical treatment

Intracranial saccular aneurysms frequently cause devastating neurologic injury when they rupture. With recent improvements in diagnostic imaging, however, an increasing number of aneurysms are now diagnosed in the unruptured state. Controversy exists regarding the appropriate management of these lesions. We have retrospectively examined a group of 86 patients from Connecticut with 104 intracranial aneurysms to determine whether small (less than 10 mm in greatest diameter) aneurysms have potential for rupture, and whether there is a role for prophylactic surgical therapy for these unruptured aneurysms. The majority of ruptured and unruptured aneurysms in the series measured less than 10 mm in greatest diameter. Out of a total of 82 patients who underwent surgical therapy, 44 had surgery for unruptured aneurysms. The major surgical morbidity in this group was 2%. We conclude that surgical therapy for small unruptured intracranial aneurysms may be beneficial since these lesions likely have substantial potential for rupture and because surgical treatment carries an acceptable risk.

Borrelia burgdorferi decreases hyaluronan synthesis but increases IL-6 production by fibroblasts

Despite the prevalence of clinical data on human Lyme disease, little is known about the immunopathologic effects of the causative organism on the host. We studied the effect of Borrelia burgdorferi on hyaluronan (hyaluronic acid, HYA) production and the effect on interleukin-6 (IL-6) synthesis by cultured fibroblasts. The cell line employed in this study produced an average of 1406 ng of hyaluronan/ml within 48 h. Using both a morphological staining protocol and a quantitative radiometric assay, we noted that in the presence of a low dose of Borrelia (9.4 x 10(5) cells/ml) the hyaluronan production decreased to an average of 1008 ng/ml, a significant difference (p < 0.05) from the amount of hyaluronan produced by the cells alone. The reduction was even more significant (p < 0.01) when a higher dose of Borrelia (9.4 x 10(6) cells/ml) was used giving an average hyaluronan concentration of 682 ng/ml. In contrast, we found that Borrelia stimulated the cells to produce IL-6 from a baseline of 293 pg/ml to a maximal value of 842 pg/ml (p < 0.01). The spirochetes had no significant effect on cell viability, nor were we able to demonstrate invasion of the cells by the bacteria. Both a decrease in hyaluronan and an increase in IL-6 may correlate with the pathogenicity of Lyme disease in man.

Interface pressure measurements of support surfaces with subjects in the supine and 45-degree Fowler positions

In the past 20 years there has been a dramatic increase in different types of support surfaces to reduce the incidence of pressure ulcers. The purpose of this study was to determine the effect of static air overlays (Sof-Care and Tendercloud), replacement mattresses (Dermarest and Therarest), and a standard hospital mattress on tissue interface pressures in healthy subjects. A convenience sample of 25 subjects had tissue interface measurements obtained under the sacrum and heel bony prominences on the five support surfaces in the supine and 45-degree Fowler's positions. A repeated measures analysis of variance (p < 0.05) indicated that the Dermarest, Therarest, Sof-Care, and Tendercloud support surfaces reduced pressure significantly under the sacral bony prominence compared with the standard hospital mattress. Heel interface pressure measurements were significantly higher than sacral interface pressure measurements. There was no significant difference between supine and 45-degree Fowler's positions with respect to tissue interface pressures.

Antibodies specific for the human retinoblastoma protein identify a family of related polypeptides

Even though the retinoblastoma gene is one of the best-studied tumor suppressor genes, little is known about its functional role. Like all tumor suppressor gene products, the retinoblastoma protein (pRB) is thought to inhibit some aspect of cell proliferation. It also appears to be a cellular target of several DNA tumor virus-transforming proteins, such as adenovirus E1A, human papillomavirus E7, or simian virus 40 large T antigen. To help in the analysis of pRB, we have prepared a new set of anti-human pRB monoclonal antibodies. In addition to being useful reagents for the study of human pRB, these antibodies display several unexpected properties. They can be used to distinguish different subsets of the pRBs on the basis of their phosphorylation states. Some are able to recognize pRB homologs in other species, including mice, chickens, and members of the genus Xenopus. In addition, some of these antibodies can bind directly to other cellular proteins that, like pRB, were originally identified through their association with adenovirus E1A. These immunologically cross-reactive proteins include the p107 and p300 proteins, and their recognition by antibodies raised against pRB suggests that several members of the E1A-targeted cellular proteins form a structurally and functionally related family.