362. Saliva as a Reliable Sample Type for Mass SARS-CoV-2 Testing Strategies

Background

Quickly detecting and isolating individuals positive for SARS-CoV-2 is essential for limiting virus spread. Policy makers rely on the number of active cases to make decisions, and individuals use this information to evaluate risk should they return to public spaces. Robust testing strategies have been plagued with limited authorized diagnostic assays and high test prices, with large-scale implementation hampered by worldwide supply chain issues.

Methods

Having identified its potential early in the pandemic, we simplified saliva-based COVID-19 diagnostic testing by (1) not requiring collection tubes with preservatives, (2) replacing nucleic acid extraction with a simple enzymatic and heating step, and (3) testing specimens for SARS-CoV-2 in dualplex RT-qPCR. Moreover, we validated this approach (“SalivaDirect”) with reagents and instruments from multiple vendors to circumvent supply chain disruptions.

Results

SalivaDirect’s simplified protocol does not compromise on sensitivity. In our hospital cohort, we found a high positive agreement (94%) between saliva tested with SalivaDirect and nasopharyngeal swabs tested with a commercial RT-qPCR kit. With the National Basketball Association we tested 3,779 saliva specimens from healthy individuals and detected low rates of invalid (0.3%) and false-positive (< 0.05%) results. Using comparative assays and sample types, we also demonstrated SalivaDirect to efficiently detect SARS-CoV-2 in asymptomatic individuals.

SalivaDirect is a simplified method for SARS-CoV-2 detection

(A) Schematic overview of SalivaDirect workflow depicting the main steps of mixing saliva with proteinase K, heat inactivation, and dualplex qRT-PCR testing. Figure created with Biorender.com. (B) SARS-CoV-2 is stable in saliva for at least 7 days at 4C, room temperature (RT; 19C), and 30C without addition of stabilizing buffers. Spiked-in saliva samples of low virus concentrations (12, 25, and 50 SARS-CoV-2 copies/mL) were kept at the indicated temperature for 7 days and then tested with SalivaDirect. N1 cycle threshold (Ct) values were lower when kept for 7 days at 30C as compared to fresh specimens (Kruskal-Wallis; p = 0.03). Horizontal bars indicate the median. (C) Comparing Ct values for saliva treated with proteinase K and heat as compared to nucleic extraction yields higher N1 Ct values without extraction (Wilcoxon; p < 0.01). (D) Testing extracted nucleic acid from saliva with the N1 primer-probe set (singleplex) as compared to a multiplex assay showed stronger N1 detection in multiplex (Wilcoxon; p < 0.01). The dotted line in (B)–(D) indicates the limit of detection.

Conclusion

Saliva is a valid alternative to swabs for SARS-CoV-2 screening. Importantly, SalivaDirect enables labs to utilize existing infrastructure, improving test implementation time and requiring limited investment to scale-up to meet mass testing needs. With the safe and reliable self-collection of saliva, our vision is to help provide accessible and equitable testing solutions, especially in low-resource and remote settings.

Disclosures

Anne Wyllie, PhD, Global Diagnostic Systems (Consultant)Pfizer (Advisor or Review Panel member, Research Grant or Support)PPS Health (Consultant)Tempus Labs, Inc (Research Grant or Support) Nathan D. Grubaugh, PhD, Tempus Labs (Consultant)

COVID-19 Outcomes and Genomic Characterization of SARS-CoV-2 Isolated From Veterans in New England States: Retrospective Analysis

BACKGROUND

Clinical and virologic characteristics of COVID-19 infections in veterans in New England have not been described. The average US veteran is a male older than the general US population. SARS-CoV-2 infection is known to cause poorer outcomes among men and older adults, making the veteran population an especially vulnerable group for COVID-19.

OBJECTIVE

This study aims to evaluate clinical and virologic factors impacting COVID-19 outcomes.

METHODS

This retrospective chart review included 476 veterans in six New England states with confirmed SARS-CoV-2 infection between April and September 2020. Whole genome sequencing was performed on SARS-CoV-2 RNA isolated from these veterans, and the correlation of genomic data to clinical outcomes was evaluated. Clinical and demographic variables were collected by manual chart review and were correlated to the end points of peak disease severity (based on oxygenation requirements), hospitalization, and mortality using multivariate regression analyses.

RESULTS

Of 476 veterans, 274 had complete and accessible charts. Of the 274 veterans, 92.7% (n=254) were men and 83.2% (n=228) were White, and the mean age was 63 years. In the multivariate regression, significant predictors of hospitalization (C statistic 0.75) were age (odds ratio [OR] 1.05, 95% CI 1.03-1.08) and non-White race (OR 2.39, 95% CI 1.13-5.01). Peak severity (C statistic 0.70) also varied by age (OR 1.07, 95% CI 1.03-1.11) and O2 requirement on admission (OR 45.7, 95% CI 18.79-111). Mortality (C statistic 0.87) was predicted by age (OR 1.06, 95% CI 1.01-1.11), dementia (OR 3.44, 95% CI 1.07-11.1), and O2 requirement on admission (OR 6.74, 95% CI 1.74-26.1). Most (291/299, 97.3%) of our samples were dominated by the spike protein D614G substitution and were from SARS-CoV-2 B.1 lineage or one of 37 different B.1 sublineages, with none representing more than 8.7% (26/299) of the cases.

CONCLUSIONS

In a cohort of veterans from the six New England states with a mean age of 63 years and a high comorbidity burden, age was the largest predictor of hospitalization, peak disease severity, and mortality. Non-White veterans were more likely to be hospitalized, and patients who required oxygen on admission were more likely to have severe disease and higher rates of mortality. Multiple SARS-CoV-2 lineages were distributed in patients in New England early in the COVID-19 era, mostly related to viruses from New York State with D614G mutation.

Longitudinal immune profiling of a SARS-CoV-2 reinfection in a solid organ transplant recipient

The underlying immunologic deficiencies enabling SARS-CoV-2 reinfections are currently unknown. Here we describe a renal-transplant recipient who developed recurrent, symptomatic SARS-CoV-2 infection 7 months after primary infection. To elucidate the immunological mechanisms responsible for reinfection, we performed longitudinal profiling of cellular and humoral responses during both primary and recurrent SARS-CoV-2 infection. We found that the patient responded to the primary infection with transient, poor-quality adaptive immune responses that was further compromised by intervening treatment for acute rejection of the renal allograft prior to reinfection. Importantly, we identified the development of neutralizing antibodies and humoral memory responses prior to SARS-CoV-2 reinfection. However, these neutralizing antibodies failed to confer protection against reinfection, suggesting that additional factors are required for efficient prevention of SARS-CoV-2 reinfection. Further, we found no evidence supporting viral evasion of primary adaptive immune responses, suggesting that susceptibility to reinfection may be determined by host factors rather than pathogen adaptation.

Prognostic role of FDG PET-derived parameters in preoperative staging of endometrial cancer

PURPOSE

To investigate the preoperative prognostic role of ¹⁸F-FDG PET/CT in patients with endometrial carcinoma (EC).

METHODS

¹⁸F-FDG PET/CT was performed in 57 patients for EC preoperative staging. Maximum and mean standardized uptake values (SUVmax, mean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of primary tumors, at different thresholds of 40%, 50%, 60% (40-50-60), were evaluated and compared with anatomopathological features. The diagnostic performance of PET-parameters (categorized by ROC analysis) in discriminating low-intermediate and high-risk disease and the prognostic role on survival (overall survival -OS; disease free survival - DFS) was evaluated.

RESULTS

The categorized TLG40-50-60 were the only parameters related to FIGO stage I versus II-III-IV (p = 0.0035 for all). The cut-off values for risk stratification were 83.69, 61.81 and 41.32, respectively (sensitivity: 60.00%; specificity; 71.43% for all parameters). Pathological stage 1 (pT1) of the primary tumor was predicted by MTV60 and TLG40-50 (p = 0.0328, 0.0240, 0.0147, respectively). The optimal thresholds were 7.795, 99.55 and 77.58, respectively (sensitivity: 38.46%, 53.85% and 53.85%, respectively; specificity: 88.64%, 79.55% and 81.82%, respectively). SUVmax and SUVmean40-50-60 were the only parameters discriminating endometrioid from non-endometrioid subtype. The corresponding sensitivity was 64.86% and 62.16% for SUVmax and SUVmean 50-60 and 62.16% for SUVmean40; specificity was 70.00% for all parameters. The mean (SD) OS was 79.77% (3.34%) and the mean DFS was 77.89% (3.73%). The tumor type was the only variable significantly associated with OS (p = 0.0486). TLG50 > 77.58 cm³ was the only variable associated with a higher risk of relapse (p = 0.0472).

CONCLUSION

TLG40-50-60 and MTV60 of primary EC have prognostic value in discriminating FIGO and pathological staging. These results suggest a possible role of these parameters in predicting EC aggressiveness, thus improving the preoperative characterization of endometrial cancer.

Effect of analytical treatment interruption and reinitiation of antiretroviral therapy on HIV reservoirs and immunologic parameters in infected individuals

Therapeutic strategies aimed at achieving antiretroviral therapy (ART)-free HIV remission in infected individuals are under active investigation. Considering the vast majority of HIV-infected individuals experience plasma viral rebound upon cessation of therapy, clinical trials evaluating the efficacy of curative strategies would likely require inclusion of ART interruption. However, it is unclear what impact short-term analytical treatment interruption (ATI) and subsequent reinitiation of ART have on immunologic and virologic parameters of HIV-infected individuals. Here, we show a significant increase of HIV burden in the CD4⁺ T cells of infected individuals during ATI that was correlated with the level of plasma viral rebound. However, the size of the HIV reservoirs as well as immune parameters, including markers of exhaustion and activation, returned to pre-ATI levels 6–12 months after the study participants resumed ART. Of note, the proportions of near full-length, genome-intact and structurally defective HIV proviral DNA sequences were similar prior to ATI and following reinitiation of ART. In addition, there was no evidence of emergence of antiretroviral drug resistance mutations within intact HIV proviral DNA sequences following reinitiation of ART. These data demonstrate that short-term ATI does not necessarily lead to expansion of the persistent HIV reservoir nor irreparable damages to the immune system in the peripheral blood, warranting the inclusion of ATI in future clinical trials evaluating curative strategies.

While we have made considerable advancements in the treatment of HIV, most infected individuals require life-long treatment to suppress plasma viremia, underscoring the need for the development of additional therapeutic strategies that would allow durable virologic remission in the absence of antiretroviral therapy (ART). While a definitive cure has not yet been identified, the field is moving in a promising direction, and with continued efforts we may arrive at a clinically acceptable alternative to ART. Clinical validation of new treatment options likely requires patients to stop therapy while monitoring for viral rebound, but the effect of treatment interruption and its precise impact on immunologic and virologic parameters in HIV-infected individuals has not been fully delineated. In this work, we measured a significant increase of HIV burden in the CD4⁺ T cells of infected individuals who underwent ATI with subsequent plasma viral rebound. However, the size of the HIV reservoirs as well as immune parameters returned to pre-ATI levels 6–12 months after the participants resumed ART. These data suggest ATI does not lead to expansion of the persistent HIV reservoir nor irreversible damages to the immune system in the peripheral blood.

Use of pain at baseline and pain progression to predict overall survival (OS) in patients (pts) with docetaxel pretreated metastatic castration-refractory prostate cancer (CRPC): Results from the SPARC trial

5148

Background: First-line chemotherapy trials have reported that pain predicts OS in CRPC. We report relationships between OS and baseline pain –a major component of CRPC patient reported outcomes (PRO) –and pain at progression, for docetaxel pre-treated patients in a second-line chemotherapy trial in CRPC. Methods: Docetaxel pre-treated pts (N = 488) were analyzed from the multi-national, randomized, double-blind SPARC trial, comparing second-line satraplatin + prednisone vs placebo + prednisone in 950 metastatic CRPC pts. Daily pain intensity and narcotic analgesic use were recorded as a PRO from one week prior to randomization until end-of-study. Pain was measured by the 6-point Present Pain Intensity (PPI) component of the McGill-Melzack Pain Questionnaire. After randomization, weekly PPI scores were calculated as the mean of the daily PPI scores (using ≥3 daily measurements/week). Baseline pain was the mean of ≥5 daily PPI scores recorded during 7 days preceding randomization. An independent blinded review committee (IRC) determined pain progression (defined as an increase in weekly PPI score ≥1 point from baseline or ≥2 points from nadir, or a >25% increase from baseline in weekly average analgesic score for ≥2 consecutive weeks). To examine the effects of pain on OS, pts were categorized as “no pain” (PPI ≤1) or pain (PPI ≥2) by baseline assessment; and, as either pain progressors or pain non-progressors. Results: Shortened OS was observed in pts with baseline pain; median survival of 178 pts with pain was 44 weeks vs 72 weeks for 287 pts without pain (Strat. Log-rank p < 0.0001, Strat. HR 0.59; 95% CI: 0.48–0.74). IRC found disease progression in 414 (84.4%) of the docetaxel pre-treated pts with 196 of these pts showing pain progression. Pain progression was strongly linked to OS with 196 pain progressors having median OS of 47 weeks compared to 71 weeks for 292 pain non-progressors (Strat. Log-Rank p = 0.0022; Strat. HR 0.71; 95% CI: 0.57–0.87). Conclusions: Both pain at baseline and pain at progression are important prognostic indicators of OS in metastatic CRPC pts failing first-line docetaxel.

[Table: see text]

Phase I study of the effects of renal impairment on the pharmacokinetic (PK) and safety of satraplatin in patients (Pts) with refractory non-hematologic cancer

2044

Background: Satraplatin (S) is a novel oral platinum analog with demonstrated activity in the treatment of pts with platinum-sensitive malignancies. A worldwide, double-blind, placebo-controlled randomized trial evaluating S as 2nd line therapy for hormone refractory prostate cancer (HRPC) has recently completed enrollment. The current study wasis designed to understand the effect of varying degrees of renal impairiment on the safety and PK of satraplatin. Methods: The study includes 4 levels of renal dysfunction, and 8 pts/cohort: Group 1 (G1) = Normal Renal Controls; G2 = Mild renal impairment (CrCl 50–80 mL/min); G3 = Mod. impairment (CrCl 30-<50 ml/min); G4 = Severe impairment (CrCl <30 mL/min). S was administered orally at 80mg/m2/d on d1–5 every 35 days. Results: 21 pts (of a planned total of 32) have been enrolled (13M/8F), median age 63 (range 45–72). Tumor types: Bladder (6), Renal (3), Breast (2), Prostate (2), Colon (2), Other (6). Among 15 evaluable pts, the cohort distribution is G1: 6 pts, G2: 4, G3: 4, and G4: 1. Twenty-six cycles of S have been delivered, and 11 pts have completed at least 2 cycles of therapy. Hematologic toxicities during the first 2 cycles include grade (G) 3/4 neutropenia (0 pts), G 3/4 thrombocytopenia (1), and G 3/4 anemia (1). No significant cardiac, renal, hepatic, or neurologic toxicity has been observed. Nausea, vomiting, and diarrhea were mild to moderate, and controlled with oral therapy. Of 4 pts with evaluable disease, 1 has stable disease, and 3 have progressed. Conclusions: S is well tolerated in pts with varying degrees of renal dysfunction. Updated safety and PK data will be presented at the meeting.

[Table: see text]

Anagrelide metabolite induces thrombocytopenia in mice by inhibiting megakaryocyte maturation without inducing platelet aggregation

OBJECTIVE

The mechanism for anagrelide's potent platelet lowering activity in human subjects is not well defined. Studies related to anagrelide function have been hampered by its lack of activity in nonhuman primates and water insolubility. In an effort to define the mechanism whereby anagrelide exerts its therapeutic effect, we identified a water-soluble metabolite (anagrelide.met). The availability of anagrelide.met allowed, for the first time, parallel in vitro and in vivo animal studies centered on the mechanisms by which anagrelide lowers platelet levels.

MATERIALS AND METHODS

The effects of anagrelide.met on proliferation and maturation of mega-karyocytes (MKs) as well as platelet production were studied both in vitro and in vivo.

RESULTS

Anagrelide.met is capable of blocking in vitro MK migration by 20% to 40%. At 100 ng/mL, anagrelide.met selectively blocked in vitro MK maturation, resulting in a 50% decrease in the total number of CD41a(+) MKs, corresponding with a 30% decrease in MK ploidy by day 10 and a 60% decrease by day 20. Daily intraperitoneal injections of anagrelide.met 100 microg into BALB/c mice was sufficient to significantly decrease platelet counts within 24 to 48 hours, stabilizing to 40 to 50% of normal levels by day 5. This was associated with a 45% decrease in the number of developing MKs and an increase in thrombopoietin levels. Anagrelide.met did not alter WBC counts, hematocrit, or bleeding time, or lead to any apparent signs of toxicity. Furthermore, unlike the parent anagrelide compound, anagrelide.met did not inhibit ADP-induced platelet aggregation even at high concentrations (10 microg/mL).

CONCLUSIONS

We describe a cross-species reactive anagrelide metabolite that selectively inhibits MK maturation and migration, lowering platelet levels without influencing platelet aggregation.

Comparative investigations of the desensitising efficacy of a new dentifrice

OBJECTIVES

In two clinical trials of 8 weeks duration, the ability of a new dentifrice, containing potassium nitrate, stannous fluoride and sodium fluoride to reduce dentine hypersensitivity was compared with either a non-desensitising fluoride dentifrice or a commercially available desensitising dentifrice (Sensodyne F) to reduce dentine hypersensitivity.

METHOD

In both studies, the participants had to have at least two sensitive root surfaces. Subjects were stratified by baseline tactile and air blast sensitivity scores and the number of sensitive teeth and randomly allocated to 2 balanced groups. In the first study (N=81) the new dentifrice was compared with a fluoride dentifrice and in the second study (N=105) with Sensodyne F. Participants were requested to brush with their assigned dentifrice twice a day for one minute. At 4 and 8 weeks the sensitive teeth were again examined and their tactile and air blast sensitivity scores recorded.

RESULTS

In study 1, the group using the new dentifrice tolerated greater pressure after 4 (34.9 g) and 8 weeks (38.4 g) than the group using the fluoride dentifrice (22.9 g and 19.0 g, respectively). These differences were statistically significant (p<0.001). At 4 and 8 weeks, the mean air blast scores for the group using the new dentifrice (1.39 and 0.83) were lower than for the group using fluoride dentifrice (1.78 and 1.76) and were significantly different at 8 weeks (p<0.001). In study 2 the group using the new dentifrice tolerated greater pressure after 4 (40.5 g) and 8 weeks (43.7 g) than the group using Sensodyne F (27.8 g and 33.2 g, respectively). These differences were statistically significant (p<0.001). At 4 and 8 weeks, the mean air blast scores for the group using the new dentifrice (1.10 and 0.67) were significantly lower than the group using Sensodyne F (1.90 and 1.57) (p<0.001).

CONCLUSIONS

These studies demonstrate that the new dentifrice, containing potassium nitrate, stannous fluoride and sodium fluoride is significantly better at reducing dentine hypersensitivity than both the dentifrice containing sodium fluoride and the one containing potassium chloride, triclosan and sodium fluoride (Sensodyne F).

Can Joel-Cohen incision and single layer reconstruction reduce cesarean section morbidity?

OBJECTIVE

To compare an innovative cesarean section based on Joel-Cohen incision with the traditional Pfannenstiel technique in terms of operative data and post-operative recovery.

METHOD

Out of 158 randomized patients, 83 patients underwent the innovative cesarean section (Joel-Cohen incision, one-layer locked uterine suture, no peritoneization) and 75 the traditional operative approach (Pfannenstiel incision, double layer closure of the uterus, visceral and parietal peritoneization). Operative data and post-operative morbidity were compared; sample size was calculated to detect a 13% difference in the occurrence of post-operative fever with a statistical power of 80%.

RESULT

Post-operative fever was not different in the two groups. Total operating time was shorter with the innovative technique: 31.6 +/-1.38 min vs. 44.4+/-1.44 (P=0.0001) and fewer sutures were used: 3.6+/-0.13 vs. 6+/-0.13 (P=0.001). Patients operated by the new technique began moving sooner and intestinal function restarted earlier.

CONCLUSION

The proposed technique made for shorter operating times and faster recovery but no decrease in puerperal morbidity.

Desensitizing efficacy of a new dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride

PURPOSE

To evaluate the relative effectiveness provided by a new dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength) for reducing dentin hypersensitivity over an 8-wk period, as compared to that provided by a commercially-available antihypersensitivity dentifrice containing 5.0% potassium nitrate and 0.76% sodium monofluorophosphate in a dicalcium phosphate base (Fresh Mint Sensodyne dentifrice).

MATERIALS AND METHODS

To qualify for participation in this examiner-blind study, male and female adults from the San Francisco, California area were required to present with tactile and air blast dentin hypersensitivity in at least 2 non-molar teeth at two examinations, spaced 1 wk apart. Qualifying subjects were randomized into two treatment groups, which were balanced for gender, age, and baseline sensitivity scores. Subjects were provided with a soft-bristled toothbrush. Examinations for tactile and air blast sensitivity were repeated after 4 wks' use of the study dentifrices, and again after 8 wks' usage.

RESULTS

101 subjects complied with the protocol, and completed the entire study. After 4 wks, subjects assigned to the Colgate Sensitive Maximum Strength group exhibited a statistically significant improvement over the Fresh Mint Sensodyne dentifrice group with respect to tactile sensitivity scores, and a statistically significant improvement over the Sensodyne dentifrice group with respect to air blast sensitivity scores. Correspondingly significant improvements were presented after 8 wks. Thus, the results of this examiner-blind clinical study support the conclusion that Colgate Sensitive Maximum Strength dentifrice provided superior levels of control of tactile and air blast sensitivity than did the clinically tested, commercially-available Sensodyne anti-hypersensitivity dentifrice.

Desensitizing efficacy of Colgate Sensitive Maximum Strength and Fresh Mint Sensodyne dentifrices

PURPOSE

To investigate the relative effectiveness provided by a new dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base (Colgate Sensitive Maximum Strength dentifrice) for reducing dentin hypersensitivity over an 8-wk period, as compared to that provided by a commercially-available antihypersensitivity dentifrice containing 5.0% potassium nitrate and 0.76% sodium monofluorophosphate in a dicalcium phosphate base (Fresh Mint Sensodyne dentifrice).

MATERIALS AND METHODS

To qualify for participation in this examiner-blind clinical study, male and female adults from the central New Jersey area were required to present with tactile and air blast dentin hypersensitivity in at least two non-molar teeth at two examinations, spaced 1 wk apart. Qualifying subjects were randomized into two treatment groups, which were balanced for gender, age, and baseline sensitivity scores. Subjects were provided with a soft-bristled toothbrush. Examinations for tactile and air blast sensitivity were repeated after 4 wks' use of the study dentifrices, and again after 8 wks' usage. 97 subjects complied with the protocol, and completed the entire study.

RESULTS

After 4 wks, subjects assigned to the Colgate Sensitive Maximum Strength dentifrice group exhibited a statistically significant improvement over the Sensodyne dentifrice group with respect to tactile sensitivity scores, and a statistically significant improvement over the Sensodyne dentifrice group with respect to air blast sensitivity scores. Correspondingly significant improvements were presented after 8 wks. Thus, the results of this examiner-blind clinical study support the conclusion that the Colgate Sensitive Maximum Strength dentifrice containing 5.0% potassium nitrate and 0.454% stannous fluoride in a silica base provided superior levels of control of tactile and air blast sensitivity than the clinically tested, commercially-available anti-hypersensitivity dentifrice Sensodyne dentifrice containing 5.0% potassium nitrate and 0.76% sodium monofluorophosphate in a dicalcium phosphate base.

Effects of fluoride toothpaste on etched enamel of orthodontic patients

OBJECTIVE

To investigate the effects of fluoride toothpaste on acid-etched enamel by means of a scanning electron microscope.

METHODS

Permanent first premolars extracted for orthodontic reasons were etched with 37% H3PO4. They were divided into two groups in pairs of contralateral teeth. Group 1 was treated with fluoride toothpaste slurry; Group 2 was treated with deionized water. Treatment time was three weeks (one hour, 3 times a day).

RESULTS

At the conclusion of the experiment, large amounts of precipitate were observed on the enamel surface of the teeth that were treated with fluoride toothpaste slurry. The etched structures were no longer evident and the enamel surface was smooth. The acid resistance of the teeth was significantly enhanced. However, clearly etched enamel structures were visible on the enamel surface of the teeth that were treated with deionized water.

CONCLUSION

Fluoride toothpaste could promote the remineralization of etched enamel and enhance its resistance to acid attack.

In vitro and in vivo antitumor effects of retrovirus-mediated herpes simplex thymidine kinase gene-transfer in human medulloblastoma

Herpes simplex virus thymidine kinase gene (HSVtk) transfer together with treatment with the prodrug ganciclovir (GCV) represents the most commonly used suicide gene approach for the gene therapy of human central nervous system malignancies. Despite encouraging results reported in clinical trials conducted in adults, very little is known about the feasibility of this approach for the treatment of CNS tumors of childhood. We studied the effects of the HSVtk/GCV system on human medulloblastoma cells in vitro and in vivo. The transfer of tk gene to medulloblastoma cells was capable of mediating cell suicide in vitro and in vivo upon treatment with GCV, but the overall effect in vivo appeared to be suboptimal. The relatively low sensitivity of the medulloblastoma cells to viral infection and a limited bystander effect, coupled with a low expression of connexin-43 protein, might partially explain these results. Whether this is a peculiarity of the cell line studied or a general characteristic of medulloblastoma remains to be determined. These findings should be taken into account for the future planning of gene therapy trials for human medulloblastoma.

A comparison between different methods for the determination of reduced and oxidized glutathione in mammalian tissues

In this study, three rapid assay techniques for the determination of glutathione, one enzymatic, one fluorometric and one newly patented colorimetric method, were compared by measuring reduced (GSH) and oxidized (GSSG) glutathione in guinea-pig heart and liver. The HPLC technique was used as a standard, since it is considered the most reliable assay method. In heart, all methods measured the same levels of GSH (about 1 mumole/g wet tissue), whereas in liver the fluorometric assay gave GSH levels about half as high as those measured by the other methods (about 3 vs. 7 mumoles/g wet tissue). Conversely, the fluorometric assay grossly overestimated GSSG concentration (by 5 to 8 times) in both heart and liver. These results confirm previous doubts about the use of the fluorometric technique for GSSG determination in mammalian tissues and also raise some questions about its use for the measurement of GSH in liver. In this tissue, the GSH concentration determined by the fluorometric method was shown to be inversely correlated with the size of the sample, suggesting the presence of some quenching material.

Screening for developmental dysplasia of the hip: from theory to practice. Collaborative Group DDH Project

OBJECTIVE

To evaluate an organizational model for neonatal population screening for developmental dysplasia of the hip.

METHODS

In 4648 neonates born in six hospitals of the Lombardy region, screening for developmental dysplasia of the hip was done using the Ortolani-Barlow maneuver and ultrasonography.

RESULTS

The frequency of positive results of clinical and ultrasound examinations carried out in the hospitals varied considerably as a result of difficulties in the Ortolani-Barlow test reproducibility and in the low sensitivity of the clinical examination when compared to ultrasonography. Neonatal screening results implied a large number of subjects with a IIa hip, according to Graf's system; as these subjects require follow-up, the cost of this type of screening is high. Ultrasound findings were normal at 69 days of life in 88% and 75% of subjects, respectively, with unilateral and bilateral type IIa hip.

CONCLUSION

This study evaluated various organizational models for screening (for different time periods and for selected populations) in relation to the cost-benefit ratio and demonstrated the different problems that still impede identification of a correct screening model.

Mechanisms of plumbagin action on guinea pig isolated atria

In electrically driven guinea pig left atria, plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone; 0.5-10 microM) produced a marked positive inotropic effect that was about 65% that caused by isoprenaline in the same experimental conditions. The effect was mainly not dependent on catecholamine release from adrenergic stores. An EC50 of 3 microM was calculated from the concentration-response curves. The increase in force of contraction was followed by a nonreversible contracture. Plumbagin was reduced by cardiac mitochondrial and soluble reductases with consequent generation of large amounts of superoxide anion. The assay of reduced glutathione/oxidized glutathione content in atria, treated with 10 microM plumbagin and frozen at the appearance of increase in diastolic tension, showed a significant decrease in reduced glutathione (-52% with respect to control atria) and a 5-fold increase in oxidized glutathione levels. Moreover, in the same experimental conditions a significant decrease in adenosine triphosphate (-55% with respect to the controls) and in adenylate energy charge (from 0.92-0.64) was observed. Of the enzymes and transport systems involved in the control of the cardiac contractility, the sarcoplasmic reticulum Ca2+ pump seemed to be a specific target for plumbagin. After 30 min of incubation with cardiac sarcoplasmic reticulum membrane vesicles, plumbagin inhibited Ca2+ uptake by the pump in a concentration-dependent manner (IC50 = 3 microM). On the basis of these results, the increase in diastolic tension caused by plumbagin appears to be related to intracellular Ca2+ accumulation, due both to the low availability of adenosine triphosphate for ionic pumps and direct inhibition of Ca2+ reuptake in sarcoplasmic reticulum.

In vitro and in vivo protection against kainate-induced excitotoxicity by melatonin

In this study, the protective effect of melatonin against kainate (KA)-induced neurotoxicity was evaluated in vitro and in vivo. In rat brain synaptosomes, KA-induced oxidative stress was measured as shown by significant increases in both the basal generation of reactive oxygen species (ROS), assessed by a fluorescent method, and lipid peroxidation, evaluated as malondialdehyde (MDA) levels. Melatonin decreased, in a concentration-dependent manner, KA-induced lipid peroxidation. The intrinsic fluorescence of melatonin molecule hindered the evaluation of its protective effect against KA-induced ROS generation. However, melatonin was able to reduce FeSO4/ascorbate-induced ROS generation. The melatonin protective effect was confirmed by in vivo experiments: 73% of rats injected with KA (10 mg/kg i.p.) died within 5 days; melatonin administration i.p. significantly reduced mortality of the animals. The present results suggest that melatonin might be considered a pharmacological agent for the treatment of neurodegenerative pathologies.

Anticalculus efficacy of three dentifrices

PURPOSE

To evaluate the anticalculus effect of three commercial dentifrices.

MATERIALS AND METHODS

A 12-week independent and double-blind clinical study was conducted on a population of calculus-forming adult male and female subjects in Budapest, Hungary to directly compare the anticalculus efficacy of three commercially-available dentifrices, as compared to a placebo dentifrice. The three commercially-available anticalculus dentifrices compared in this clinical study to a 0.243% sodium fluoride/silica placebo dentifrice were as follows: (1) A dentifrice containing 1.3% soluble pyrophosphate and 1.5% of a PVM/MA copolymer in a 0.243% sodium fluoride/silica base. (2) A dentifrice containing 0.3% triclosan and 2% of a PVM/MA copolymer in a 0.243% sodium fluoride/silica base. (3) A dentifrice containing 0.3% triclosan and 0.75% zinc citrate in a 1.14% sodium monofluorophosphate/silica base.

RESULTS

All three anticalculus dentifrices provided statistically significant reductions in supragingival calculus formation, as compared to a placebo dentifrice, after 12 weeks of use. The reductions in supragingival calculus formation ranged from 39% to 55%, as compared to a placebo dentifrice, for the three commercially-available anticalculus dentifrices. There was no statistically significant difference among the three commercially-available dentifrices with regard to anticalculus efficacy.

Effect on plaque removal and gingivitis of a triclosan-copolymer pre-brush rinse: a six-month clinical study in Canada

The effect on plaque removal and gingivitis of using a pre-brush rinse containing 0.03 per cent triclosan (Irgacare MP, Ciba-Geigy Corp.) and 0.125 per cent of a copolymer of polyvinylmethyl ether and maleic acid over a six-month period, versus using a matching placebo pre-brush rinse, was assessed in this clinical study. Subjects were instructed to rinse their mouths for one minute, twice daily (morning and evening), with 15 mL of their assigned pre-brush rinse. Immediately after rinsing, subjects brushed their teeth for 30 seconds using the dentifrice and toothbrush supplied to them at the outset. Subjects were instructed to refrain from any other oral hygiene procedures throughout the duration of the study. Plaque and gingivitis examinations were conducted after three months and again after six months. At the conclusion of the study (six months), the triclosan/copolymer pre-brush rinse demonstrated an advantage of 24.8 per cent for plaque removal and a 22.1 per cent reduction in gingivitis, when compared to the matching placebo pre-brush rinse. These advantages in plaque removal and gingivitis reduction were statistically significant. The six-month effect of the triclosan/copolymer pre-brush rinse was even greater on "the more difficult to brush" surfaces of the teeth, as determined by the use of the Plaque Severity Index and the Gingivitis Severity Index.(ABSTRACT TRUNCATED AT 250 WORDS)

A six-month clinical study of the effect of a pre-brush rinse on plaque removal and gingivitis

The effect of a pre-brush rinse (Colgate Plax, Colgate UK) containing 0.03% triclosan (Irgacare MP, Ciba-Geigy Corp.) and 0.125% of a copolymer of methoxyethylene and maleic acid (Gantrez, ISP Corp.) on existing plaque and gingivitis over a 6-month period was compared to a matching placebo pre-brush rinse. The study was a double-blind, parallel design utilising 125 subjects, 117 of whom completed the 6-month period. Subjects rinsed twice daily for 60 seconds with 15 ml of their assigned pre-brush rinse. Immediately after rinsing, subjects brushed their teeth for 30 seconds with a fluoride dentifrice and a soft-bristled toothbrush. After 3 and 6 months, the levels of plaque and gingivitis were significantly lower in the triclosan/copolymer rinse group when compared with the placebo rinse group. The beneficial effects of the active rinse were particularly evident on the surfaces of teeth which are poorly cleaned by mechanical procedures. No side effects, such as staining, were observed or reported. The results indicate that the twice daily use of a pre-brush rinse containing triclosan and copolymer can provide significant adjunctive benefits to mechanical oral hygiene procedures.

Caesium contamination in human milk and transfer factor from diet

A study on caesium contamination in human milk, as a consequence of the Chernobyl fallout, was conducted in 1989 on a group of women from one of the areas of northern Italy most heavily affected by the radioactive fallout. Their diet was studied, and the caesium intake was calculated by using the mean food activity concentration in that area. The caesium transfer factor was evaluated both as the ratio of caesium concentration in mother's milk to the daily intake, and by using a simplified milk compartment model.

Clinical comparison of the anticalculus efficacy of three commercially available dentifrices

A three-month, double-blind, parallel and unsupervised clinical study was conducted to compare the effects on supragingival calculus formation of the following four dentifrices: 1) A placebo dentifrice containing 0.243% sodium fluoride in a silica base. 2) A commercially available anticalculus dentifrice containing 5.0% soluble pyrophosphate in a 0.243% sodium fluoride silica base. 3) A commercially available anticalculus dentifrice containing 1.3% soluble pyrophosphate and 1.5% of a Gantrez copolymer in a 0.243% sodium fluoride silica base. 4) A commercially available anticalculus dentifrice containing 3.3% soluble pyrophosphate and 1.0% of a Gantrez copolymer in a 0.243% sodium fluoride silica base. The three-month results indicated that the three commercially available anticalculus dentifrices provided statistically significant reductions (at the 99% level of confidence) in supragingival calculus formation of 43.87%, 46.60%, and 51.32% respectively, as compared to the placebo dentifrice. There was no statistically significant difference among the three commercially available anticalculus dentifrices.

Effect of a dentifrice containing triclosan and a copolymer on plaque formation: a 6-week clinical study

A 6-week, double-blind, clinical study was conducted to determine the effect on plaque formation of a dentifrice containing 0.3% triclosan and 2% of a copolymer of methoxyethylene and maleic acid as compared to a placebo dentifrice. Ninety-one male and female adult subjects with baseline Quigley-Hein Plaque Index scores of 1.5 or greater were entered into the study. Eighty-six subjects completed the entire 6 weeks of the study. Subjects were initially stratified into two balanced groups using their baseline Plaque Index score and each group was then randomly assigned to the use of one of the two test dentifrices. All subjects received an oral prophylaxis at the start of the study. Subjects were given either the triclosan/copolymer dentifrice or the placebo dentifrice and a soft-bristled toothbrush for home use and were instructed to brush their teeth twice daily (morning and evening) for 1 minute at each toothbrushing. At the end of the 2, 4 and 6 weeks' use of their assigned dentifrice, the subjects had their teeth evaluated for plaque formation. The results indicated that the group assigned to the triclosan/copolymer dentifrice had 11.89%, 11.83% and 20.01% less plaque formation after 2, 4 and 6 weeks' use of the dentifrices, respectively, than the group assigned to the placebo dentifrice. All reductions in plaque formation were statistically significant at the 97% level of confidence or greater. The effect was more pronounced on the tooth surfaces that had the heaviest plaque formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical comparison of the anticalculus effect of two mouthrinses

A three-month, double-blind clinical study was conducted to compare the effects of supragingival calculus deposits of a mouthrinse containing soluble pyrophosphate and a copolymer of methoxyethylene and maleic acid, as compared to a mouthrinse containing only soluble pyrophosphate and a placebo mouthrinse. Male and female adult subjects were stratified into three balanced groups according to baseline calculus scores obtained from a pre-test period. They received an oral prophylaxis and were assigned to the use of one of the three test mouthrinses. All subjects used a commercially available dentifrice containing 0.76% sodium monofluorophosphate in a silica base. The results from the three-month calculus examination indicated that the soluble pyrophosphate/copolymer mouthrinse reduced supragingival deposits by 31.70% (P less than 0.03), as compared to the placebo mouthrinse. The mouthrinse containing only soluble pyrophosphate did not provide a statistically significant reduction in calculus deposits, as compared to the placebo mouthrinse.

[Multiple coronary artery-left ventricle fistulas in a patient with apical hypertrophic cardiomyopathy: an unusual cause of angina pectoris]

A 50 year-old man had a history of crescendo exertional angina. Echocardiographic and electrocardiographic findings were typical of apical hypertrophic cardiomyopathy. Selective coronary angiography showed no atherosclerotic lesions, but there was a stream of dye into the left ventricle, via a tiny plexus of intramural vessels, from the distal third of the anterior descending coronary artery. The origin of myocardial ischemia has been related to a "steal" phenomenon, while this vascular anomaly could represent a disorder of the thebesian system, possibly due to the "disarray" of myocardial cells typical of hypertrophic cardiomyopathy.

[Total atriventricular block in recurrent rheumatic fever]

Complete heart block (CHB) during acute rheumatic fever is rarely reported. The Authors describe the case of a young woman with rheumatic relapse and CHB that required temporary and then, definitive cardiac stimulation.

[Echinococcal cyst of the right ventricle: diagnostic role of 2-dimensional echocardiography]

A case of cardiac echinococcosis in a 22 year-old woman is reported. Clinical findings and cardiac catheterization data offered only presumptive evidence of an intraventricular mass but failed to make a positive diagnosis of cardiac involvement by hydatid disease. Using Two-Dimensional Echocardiography (2-DE) we were able to identify a rounded structure with multiple loculation into the right ventricle, highly suggestive of a hydatid cyst. Surgery confirmed our findings. We confirm the ability of 2-DE to detect and characterise intracardiac masses and we suggest that 2-DE could be considered the procedure of choice in the diagnosis of cardiac hydatid disease.

[Closure of Botallo's ductus arteriosus with indomethacin. Considerations on 4 cases]

Persistence of Patent Ductus Arteriosus (PDA) frequently occurs in preterm infants. In a remarkable number of cases, PDA may undergo spontaneous closure. In other cases, especially in patients with respiratory problems, a ductal left-to-right shunt may compromise the cardiac-respiratory function. Until a few years ago, surgery was the only possible therapy. Recently, pharmacological closure of the duct by means of Indomethacin, a powerful inhibitor of prostaglandin synthesis, was successfully carried out. The medical treatment, however, appears to be less effective if it is carried out on patients older than 2 weeks. It has also been reported that in patient with a very low birthweight and with lack of muscular tissue in the duct wall, closure of the duct may be transient. It is the purpose of this communication to report observations made on 4 preterm infants of 24-33 weeks gestational age, and with a weight range of 660 to 2.280 g. They received Indomethacin via naso-gastric tube, in a single dose of 0,3 mg/Kg, within 8 days of age. Successful closure of the PDA was obtained in all cases. The pharmacological treatment resulted also in reductions in ventilatory support requirements, reduced respiratory component of acidosis, reduced pCO2, increased pO2. A second administrations of Indo was necessary only in one case, and it was followed by permanent closure of the duct. Collateral effects, such as reduced diuresis and reduced number of platelets, were transient. Indo therapy was successful regardless of very low birthweight: in three cases, birthweight was under 1.000 g.(ABSTRACT TRUNCATED AT 250 WORDS)

Transient aplastic crisis in hereditary spherocytosis

In this study the case of a child affected with hereditary spherocytosis, who presented with a presumably viral infection induced transient aplastic crisis, is described. The bone marrow aspirate showed phagocytosis of erythrocytes and nucleated cells by reticular cells. The possible pathogenetic role of bone marrow phagocytosis in aplastic crises in patients with haemolytic anaemias is discussed.

Neonatal haemophilus aphrophilus meningitis

Case report of a neonatal meningitis due to Haemophilus influenzae. The treatment with ampicillin was ineffective because of insensitivity. This case demonstrates the importance of a proper bacteriological identification in order to avoid ineffective or delayed treatment.