Blood pressure stability in a normotensive population during intake of a monophasic oral contraceptive containing 20 microg ethinylestradiol and 75 g gestodene

OBJECTIVES

Evaluation of the impact of a monophasic gestodene-based oral contraceptive on blood pressure in a population that was normotensive at baseline.

METHODS

Data on blood pressure were retrospectively analyzed from four large prospective clinical phase III trials with an oral contraceptive containing 20 microg ethinylestradiol and 75 microg gestodene. A total of 1342 young fertile women were evaluated after 12 treatment cycles.

RESULTS

The mean systolic and diastolic blood pressure did not change during treatment. Approximately 89% of women were normotensive at baseline and 93% at the end of the treatment period. Only a few women (< or = 1%) were hypertensive at baseline; an increase in this prevalence was not found after 12 cycles of oral contraceptive use. The number of women who experienced a blood pressure increase was almost identical to the number who experienced a decrease. Approximately 90% of women had either a negligible blood pressure change of maximal +/- 10 mmHg or a decrease.

CONCLUSIONS

The findings of this retrospective analysis confirm that monophasic gestodene has a negligible effect on blood pressure in users who were normotensive before treatment began.

Open, multicenter comparison of efficacy, cycle control, and tolerability of a 23-day oral contraceptive regimen with 20 microg ethinyl estradiol and 75 microg gestodene and a 21-day regimen with 20 microg ethinyl estradiol and 150 microg desogestrel

This prospective, open, randomized study was conducted to compare the contraceptive reliability, cycle control, and tolerability of a 23-day regimen with 20 microg ethinyl estradiol (EE) and 75 microg gestodene (GSD) and a 21-day regimen with 20 microg EE and 150 microg desogestrel (DSG). Participants took either 23 tablets with active substances plus 5 placebo tablets (23-day EE/GSD) or 21 tablets with active substances followed by 7 days without pill-taking (21-day EE/DSG). Contraceptive efficacy, cycle control, and tolerability were evaluated over a period of seven cycles. Efficacy data gathered from 5967 treatment cycles (23-day EE/GSD: 2975 cycles; 21-day EE/DSG: 2992 cycles) were obtained from 890 participants (445 in each group). Both preparations proved to be effective contraceptives and provided good cycle control. No pregnancy during treatment was recorded. This resulted in a study Pearl Index of 0.0 for both treatments. For 23-day EE/GSD, 32.4% of participants reported at least one intracyclic bleeding episode during Cycles 2-4 (primary target) compared to 31.5% for 21-day EE/DSG. In the 23-day EE/GSD group, intracyclic bleeding episodes were reported by 48.8% of the participants in Cycle 1 but in only 15.1% in Cycle 7, and in the 21-day regimen group by 43.4% in Cycle 1 and only 14.2% in Cycle 7. Overall, intracyclic bleeding was reported in 20.9% of cycles for both treatments.A greater number of 23-day EE/GSD participants had shorter withdrawal bleeding periods than with 21-day EE/DSG. In significantly (p <0.0001) more cycles in the 23-day EE/GSD group participants reported withdrawal bleeding periods that lasted only 1-4 days compared to the 21-day EE/DSG group. For the majority of the treatment cycles, the median number of bleeding days in the 23-day EE/GSD group was 4 days and in the 21-day EE/DSG group 5 days. Both preparations were well tolerated and showed a similar adverse events pattern. The discontinuation rate because of adverse events was low (23-day EE/GSD: 6.1%; 21-day EE/DSG: 5.6%). No serious vascular adverse events were reported. More than 82% in the 23-day EE/GSD group and 79% in the 21-day EE/DSG group either lost more than 2 kg of weight or did not gain weight during the study. The treatment effect on blood pressure was negligible. There were no appreciable changes in mean laboratory values over the course of the study compared to baseline.

Double-blind, multicenter comparison of efficacy, cycle control, and tolerability of a 23-day versus a 21-day low-dose oral contraceptive regimen containing 20 microg ethinyl estradiol and 75 microg gestodene

This prospective, double-blind, randomized study was conducted to compare the contraceptive reliability, cycle control, and tolerability of a 23-day versus a 21-day oral contraceptive regimen containing 20 microg ethinyl estradiol and 75 microg gestodene. Participants took trial medication daily for 28 days, either 23 tablets with active substances plus 5 placebo tablets or 21 tablets with active substances plus 7 placebo tablets. Contraceptive efficacy, cycle control, and tolerability were evaluated over a period of seven cycles. Efficacy data gathered from 4,878 treatment cycles (23-day regimen: 2,362 cycles; 21-day regimen: 2,516 cycles) were obtained from 703 participants (23-day regimen, n = 342; 21-day regimen, n = 361). Both preparations proved to be effective contraceptives and provided good cycle control. One pregnancy because of method failure was recorded in each treatment group. This resulted in a study Pearl Index of 0.5 for each treatment. For the 23-day regimen, 36.0% of participants reported at least one intracyclic bleeding episode during Cycles 2-4 (primary target) compared to 37.1% in the 21-day regimen. In the 23-day regimen group, intracyclic bleeding episodes were reported by 42.4% of the participants in Cycle 1 but only in 14% in Cycle 7 and in the 21-day regimen group by 44.6% in Cycle 1 and only 17.3% in Cycle 7. Overall, intracyclic bleeding was reported in 21.9% of the 23-day regimen cycles and in 22.7% of the 21-day regimen cycles.A greater number of 23-day regimen participants had shorter withdrawal bleeding periods than with the 21-day regimen. In significantly (p <0.0001) more cycles in the 23-day regimen group, participants reported withdrawal bleeding periods that lasted only 1-4 days compared to the 21-day regimen group. For the majority of the treatment cycles, the median number of bleeding days in the 23-day regimen group was 4 days and in the 21-day regimen group 5 days. Both preparations were well tolerated and showed a similar adverse events pattern. The discontinuation rate because of adverse events was low (23-day regimen, 6%; 21-day regimen, 4%). No serious vascular adverse events were reported. More than 75% of the women in both groups either lost more than 2 kg of weight or did not gain weight during the study. The treatment effect on blood pressure was negligible. There were no appreciable changes in mean laboratory values over the course of the study.

Comparison of two amplification technologies for detection and quantitation of human immunodeficiency virus type 1 RNA in the female genital tract. Division of AIDS Treatment Research Initiative 009 Study Team

Human immunodeficiency virus type 1 (HIV-1) RNA levels in female genital tract and peripheral blood samples were compared using two commercial amplification technologies: the Roche AMPLICOR HIV-1 MONITOR test and either the Organon Teknika nucleic acid sequence-based amplification (NASBA-QT) assay or the NucliSens assay. Estimates of HIV-1 RNA copy number were derived from internal kit standards and analyzed unadjusted and adjusted to a common set of external standards. We found a discordance rate of approximately 18% between the two technologies for the detection of HIV-1 in either the genital tract or peripheral blood samples. Detection discordance was not consistent among specimens or among women. There were no significant differences in adjusted or unadjusted estimates of HIV-1 RNA copy number in the genital tract samples using the AMPLICOR HIV-1 MONITOR test and either the NASBA-QT assay or the NucliSens assay. In addition, the estimated HIV-1 RNA copy number in peripheral blood samples did not differ when tested with the NucliSens assay and the AMPLICOR HIV-1 MONITOR test using kit standards. However, there was a significant difference in estimated RNA copy number between the NASBA-QT assay and the AMPLICOR HIV-1 MONITOR test for internal kit standards, which, as we have previously shown, was eliminated after adjustment with the external standards. Our results suggest that the Roche and Organon Teknika assays are equivalent for quantifying HIV-1 RNA in female genital tract specimens, although variation in detection does exist.

Extension of a pilot study: impact from the cytochrome P450 2D6 polymorphism on outcome and costs associated with severe mental illness

The influence of cytochrome P450 2D6 (CYP2D6) genetic variability was examined in psychiatric inpatients by evaluating adverse drug events (ADEs), hospital stays, and total costs over a 1-year period in an extension of a previously published brief report. One hundred consecutive psychiatric patients from Eastern State Hospital in Lexington, Kentucky, were genotyped for CYP2D6 expression. ADEs were evaluated by a neurologic rating scale, modified Udvalg for Kliniske Undersogelser Side Effect Rating Scale, or chart review. Information on total hospitalization days and total costs were gathered for a 1-year period. Forty-five percent of the patients received medications that were primarily dependent on the CYP2D6 enzyme for their elimination. When the analysis was restricted to just those patients in each group receiving medication heavily dependent on the CYP2D6 enzyme, the following were observed: (1) a trend toward greater numbers of ADEs from medications as one moved from the group with ultrarapid CYP2D6 activity (UM) to the group with absent CYP2D6 activity (PM); (2) the cost of treating patients with extremes in CYP2D6 activity (UM and PM) was on average $4,000 to $6,000 per year greater than the cost of treating patients in the efficient metabolizer (EM) and intermediate metabolizer (IM) groups; and (3) total duration of hospital stay was more pronounced for those in CYP2D6 PM group. Variance of hospital stays and costs calculated from these preliminary data suggests that 1,500 to 2,000 patients must be evaluated over at least a 1-year period to determine whether the CYP2D6 genetic variation significantly alters the duration of hospital stay and costs.

Genetic relationships of grizzly bears (Ursus arctos) in the Prudhoe Bay region of Alaska: inference from microsatellite DNA, mitochondrial DNA, and field observations

Grizzly bears are abundant in the region of the Prudhoe Bay oil fields in northern Alaska. We used field observations and molecular genetic data to identify parent-offspring and sibling relationships among bears in this region. We determined genotypes at 14 microsatellite DNA loci and the cytochrome b gene of mitochondrial DNA (mtDNA) for 36 bears. We identified 17 possible mother-offspring pairs and 8 possible father-offspring pairs. This includes verification of the relationships of 14 mother-offspring pairs identified from field observations. Three additional mother-offspring pairs and all eight father-offspring pairs were determined from genetic and age data. Relatedness coefficients based on numbers of shared alleles between individuals were as expected: approximately 0.50 for parent-offspring and sibling pairs and approximately 0.75 for a father-offspring pair resulting from a father-daughter mating. The level of genetic variation (mean number of alleles per locus = 6.6, mean heterozygosity = 70%) and allele frequencies in grizzly bears in the Prudhoe Bay region are similar to those in other parts of the species' range.

A 3-month clinical investigation comparing the safety and efficacy of a novel electric toothbrush (Braun Oral-B 3D Plaque Remover) with a manual toothbrush

PURPOSE

To compare the efficacy and safety of a novel electric toothbrush (Braun Oral-B 3D Plaque Remover) with a standard reference ADA manual toothbrush.

MATERIALS AND METHODS

114 subjects were included in a 3-month randomized, parallel group, examiner-blind study and divided into two groups: 3D users and manual toothbrush users. Subjects were instructed to brush twice daily for 2 minutes. Evaluation of oral soft and hard tissue for safety, plaque, gingivitis and bleeding was conducted prior to the start of product use (at baseline), at days 14 and 35, and at 3 months.

RESULTS

105 subjects (55 3D users and 50 manual toothbrush users) completed the study. At days 14, 35 and at 3 months both groups showed reductions from baseline in whole mouth plaque, gingivitis and bleeding that were statistically significant (P < 0.005), except in the case of plaque at day 35 in manual toothbrush users. At 3 months, reductions for whole mouth plaque, gingivitis and bleeding were 15%, 16% and 65%, for 3D users and 8%, 12% and 56%, for manual toothbrush users, respectively. Group differences were significant (P < 0.05) in favor of the 3D with respect to plaque reduction for the whole mouth and for interproximal and anterior lingual sites at all three time periods. With respect to gingivitis, reductions for the whole mouth and interproximal and posterior lingual sites at 3 months were significantly greater in the 3D group. There was no clinically significant soft or hard tissue abrasion in either group. In conclusion, the 3D electric toothbrush was found to be safe and had increased efficacy with respect to reduction of plaque and gingivitis compared to a manual toothbrush.

The safety and efficacy of gingival massage with an electric interdental cleaning device

The safety and efficacy of an interdental cleaning device (Braun Oral-B Interclean--ID2) used with a Flexi-Tip gingival massage attachment were evaluated in an investigator-blind comparison with manual floss. Over a 4-week period, 59 healthy volunteers were studied with respect to whole-mouth and interproximal plaque accumulation, gingival index and gingival bleeding. Eligible subjects were randomly assigned to one of the two experimental groups following a complete dental examination on Day 1. Subjects each underwent a dental prophylaxis before receiving flossing or massaging instructions. Plaque, gingivitis and gingival bleeding index scores were evaluated at Day 1 and Week 4. There was a significant reduction from baseline in all three parameters (whole-mouth and interproximal) in each of the groups, over the 4-week period. Reductions for whole-mouth and interproximal plaque scores were 20.3% and 17.0%, respectively in the ID2 group, compared with 16.2% and 13.8%, respectively in the manual floss group. Reductions for gingivitis were 13.0% and 14.1% in the ID2 group, compared with 14.0% and 16.2% in the manual floss group, and for gingival bleeding 52.2% and 53.6% in the ID2 group, compared with 51.7% and 55.6% in the manual floss group, respectively. Differences between treatment groups for each study parameter were not statistically significant. There was no significant soft tissue pathology noted in either study group. The results demonstrated that the manual floss and the interdental cleaning device, when used with the gingival massage attachment, were equally effective.

In situ radiotherapy with 111In-pentetreotide: initial observations and future directions

PURPOSE

Somatostatin and its analogues, such as octreotide and lanreotide, are used to treat neuroendocrine malignancies. Somatostatin analogues bind to somatostatin receptors (sst 1-5), which are differentially expressed in a wide variety of neoplasms. Following ligand receptor binding, a fraction of these complexes internalize. Internalization of radiolabeled somatostatin analogues, especially those that emit Auger electrons, may allow treatment of somatostatin-receptor-positive tumors by delivering a radioactive isotope to the cancer cell in a targeted fashion. 111In-pentetreotide, an sst-2-preferring somatostatin analogue, has been used for scintigraphic evaluation and management of neuroendocrine cancer patients. We hypothesized that binding and internalization of 111In-pentetreotide, an Auger electron emitter, may induce receptor-specific cytotoxicity and could be a useful therapeutic agent in somatostatin-receptor-expressing malignancies.

METHODS

To test this hypothesis, subjects who had failed conventional therapy and had somatostatin-receptor-positive malignancies, as determined by positive uptake on a 6.0 mCi 111In-pentetreotide scan, were treated with two monthly 180 mCi intravenous injections of 111In-pentetreotide. CT scans were obtained before therapy and within 30 days following the completion of the second 111In-pentetreotide dose. Toxicity was evaluated using standard criteria.

RESULTS

Fourteen patients were studied from February 1997 to August 1997. Clinical benefit occurred in six of 10 gastroenteropancreatic tumor patients. Objective partial radiographic responses occurred in two of 14 patients, and significant tumor necrosis (defined by changes in Hounsfield units) developed in six of the 10 gastroenteropancreatic tumor patients. Possible treatment-related toxicity included two patients experiencing grade 3/4 myelosuppression, and two patients had no measurable toxicity. The most common toxicity was grade 1/2 hemoglobin (N = 6).

CONCLUSION

One hundred eighty millicurie (180-mCi) doses of 111In-pentetreotide are well tolerated and are an effective therapy in some subjects with somatostatin receptor-expressing tumors. The maximal tolerated dose of 111In-pentetreotide and the optimal dosing schedules remain to be determined.

Absolute copy number and relative change in determinations of human immunodeficiency virus type 1 RNA in plasma: effect of an external standard on kit comparisons

Use of a common set of human immunodeficiency virus type 1 (HIV-1) RNA standards eliminated differences among absolute HIV-1 RNA copy number estimates made with three commercially available assays. The relative changes in the viral RNA levels determined by the commercial assays were similar and were unaffected by the use of a common set of standards.

Quantitation of human immunodeficiency virus type 1 RNA in plasma by using blood dried on filter paper

We compared whole blood dried on filter paper to the standard assay with frozen cell-free plasma for use in the quantitation of the human immunodeficiency virus RNA load in blood. RNA values from filter paper, corrected for the hematocrit, gave results comparable to those of the standard assay in terms of sensitivity and reproducibility.

Effects of specimen collection, processing, and storage conditions on stability of human immunodeficiency virus type 1 RNA levels in plasma

To define the optimal blood collection parameters for plasma human immunodeficiency virus type 1 (HIV-1) viral load testing, plasma HIV-1 RNA levels were quantitated with the NASBA HIV-1 RNA QT System from blood specimens that were collected, processed, and stored under a variety of conditions that might have affected HIV-1 RNA stability. We determined that when whole blood was processed within 2 h of specimen collection the levels of HIV-1 RNA detected in EDTA-, heparin-, and acid citrate dextrose (ACD)-anticoagulated plasma samples were comparable. The levels of HIV-1 RNA in serum specimens (mean = 4.126 log units) were significantly lower (P < 0.01) than the levels in corresponding plasma samples (mean = 4.501 log units). One cycle of freeze-thaw (-70 degrees C) did not significantly reduce the level of HIV-1 RNA detected in EDTA-, heparin-, or ACD-anticoagulated plasmas. The EDTA-anticoagulated plasmas showed the smallest decrease in HIV-1 RNA copies (0.050 log units). HIV-1 RNA levels decreased over a 6-month time period in serum as well as in EDTA-, ACD-, and heparin-anticoagulated plasmas stored at -70 degrees C. However, the only significant decreases were for serum (mean decrease = 0.317 log units) and heparin-anticoagulated samples (mean decrease = 0.384 log units). A comparison of the levels of HIV-1 RNA in cell-free plasma collected in VACUTAINER EDTA Plasma Preparation Tubes and in standard VACUTAINER EDTA tubes determined that HIV-1 RNA levels were stable for up to 30 h after collection when stored at either room temperature (mean standard deviation [SD] = +/- 0.101 log units) or at 4 degrees C (mean SD = +/- 0.102 log units) as cell-free plasma or as EDTA-anticoagulated whole blood (mean SD = +/- 0.109 log units). These data indicate that EDTA-anticoagulated plasma is the most suitable and stable matrix for HIV-1 RNA quantitation.

High viral load in semen of human immunodeficiency virus type 1-infected men at all stages of disease and its reduction by therapy with protease and nonnucleoside reverse transcriptase inhibitors

Seminal viral load is likely to be directly related to the sexual transmissibility of human immunodeficiency virus type 1 (HIV-1). However, it is not clear whether the level of HIV-1 in semen varies with the stage of infection and whether antiretroviral therapy reduces seminal viral load. A nucleic acid sequence-based amplification (NASBA) technique was used to quantify HIV-1 RNA as an indicator of infectious viral load in semen and blood plasma of homosexual men with different stages and durations of HIV-1 infection. The median viral load in a cross section of 34 men was 11,000 HIV-1 RNA copies/ml (range, <400 to 1.3 x 10(7) copies/ml) in whole semen and 5,238 HIV-1 RNA copies/ml (range, <400 to 2.8 x 10(5) copies/ml) in seminal plasma, which is 10- to 1,000-fold higher than previous estimates. Viral loads in whole semen and seminal plasma were strongly correlated with blood plasma viral load (P < 0.001) but not with blood CD4+ T-cell count (P = 0.420). Longitudinal analysis of eight subjects who progressed to AIDS showed that seminal viral load increased in most cases, with viral load consistently higher in blood plasma than in semen. Viral loads in semen and blood plasma decreased markedly in six other patients following initiation of potent combination therapy with a protease inhibitor (indinavir) and a nonnucleoside reverse transcriptase inhibitor (DMP-266). These findings have important implications for the biology of sexual transmission of HIV-1 and its potential reduction by antiretroviral therapy.

Evaluation of a quality assurance program for quantitation of human immunodeficiency virus type 1 RNA in plasma by the AIDS Clinical Trials Group virology laboratories

A number of quantitative assays have been developed by using amplification techniques to measure human immunodeficiency virus type 1 RNA in the plasma of infected individuals. The Virology Committee of the AIDS Clinical Trials Group in the Division of AIDS, National Institute of Allergy and Infectious Diseases, has established a quality assurance program (QAP) for quantitative assays of HIV-1 RNA levels in plasma. The primary objective of the QAP was to ascertain that a laboratory could maintain the precision required to have a 90% power to detect a fivefold difference in RNA copy number between two samples in the same batch. To achieve this goal, the QAP required an intra-assay standard deviation of no greater than 0.15 log10 RNA copies per ml. Panels for proficiency testing consisted of coded replicate samples and a common set of standards. To date, 41 laboratories have participated in the program and have used both commercial and in-house assays. We demonstrated that 65% of the laboratories were capable of attaining the necessary level of intra-assay precision. The fitted regressions indicated that the differences among laboratories that used the same kit were generally greater than the differences among population-average regressions for the kits themselves. The use of an external QAP and a common set of standards reduced differences both among laboratories that used the same kit and among laboratories that used different kits. Thus, use of a common set of standards across clinical trial protocols would allow for cross-protocol comparisons.

Long-acting growth hormones produced by conjugation with polyethylene glycol

Derivatives of human growth hormone (hGH) of increasing size were produced by reaction with the N-hydroxysuccinimide ester of polyethylene glycol-5000 (PEG5000), a 5-kDa reagent that selectively conjugates to primary amines. By adjusting the reaction conditions and purification procedure, it was possible to isolate hGH derivatives containing up to seven PEG moieties that altered the Stokes radius and thereby the effective molecular masses of the unmodified hormone from 22 to 300 kDa. Fortunately, the most reactive amines were ones that did not lie in either of the two sites important for receptor binding. Nonetheless, increasing the level of PEG modification linearly reduced the affinity of hGH for its receptor and increased the EC50 in a cell-based assay up to 1500-fold. Most of the reduction in affinity was the result of slowing the association rate for the receptor. The clearance rate of hGH in rats was inversely proportional to effective molecular weight and closely fit a filtration model. We have tested the potency of these analogs by injecting them daily or every 6 days into hypophysectomized rats and determining the effects on body and organ growth. The efficacy of these analogs was optimal for hGH conjugated with 5 eq of PEG5000, and the potency was increased by about 10-fold compared with unmodified hGH. Such PEG-hGH derivatives show promise as long-acting alternatives to daily injections of hGH. More generally these studies show that improving hormone clearance properties, even at the expense of reducing receptor binding affinity, can lead to dramatic increases in hormone efficacy.

A comparative clinical study of extrinsic tooth stain removal with two electric toothbrushes [Braun D7 and D9] and a manual brush

PURPOSE

To evaluate the efficacy and safety of two oscillating/rotating toothbrushes, (Braun Oral-B Plaque Remover-D7 and Braun Oral-B Ultra Plaque Remover-D9) and a manual toothbrush with respect to removing extrinsic dental stain.

MATERIALS AND METHODS

This randomized, three-way cross-over study investigated 24 subjects entering the trial, which was divided into three, 5-day periods. Over the first 4 days of the study, an intense chlorhexidine/tea rinsing regimen was employed to induce extrinsic tooth staining. On day 5, each subject was assessed for tooth stain; they then brushed for a total of 2 minutes with one of the three randomly allocated toothbrushes. Stain evaluations were repeated after 30 seconds, 1 and 2 minutes brushing, with the intensity of stain, area of stain and number of sites with < 10% stained tooth area, being recorded at each assessment.

RESULTS

Analysis of the results showed that the two electric toothbrushes were significantly better at removing stain than the manual toothbrush. In addition, the D9 was consistently more effective than the D7, with the difference with respect to stain area achieving statistical significance (P < 0.05) after 2 minute's brushing. All three brushes were found to be safe, and there was no evidence of any soft or hard tissue abrasion. It was concluded that the oscillating/rotating electric toothbrushes were more effective in removing extrinsic dental stain than a manual brush, and that compared with the D7, the newly designed Braun Oral-B Ultra Plaque Remover has an increased potential for stain removal.

Cisplatin and emesis: aspects of treatment and a new trial for delayed emesis using oral dexamethasone plus ondansetron beginning at 16 hours after cisplatin

The marked progress in controlling emesis caused by cisplatin characterizes the current status of antiemetic treatment for all chemotherapy. Cisplatin has provided a model for antiemetic studies. Strategies for controlling cisplatin-induced emesis are at least as successful when applied to other chemotherapy and persistent problems such as delayed emesis and the emesis associated with consecutive-day chemotherapy are also similar to or less severe than those observed with cisplatin. The purpose of this report is twofold: first to outline briefly therapy for cisplatin-induced emesis as illustrated by several new studies, and, second, to report on a new trial that incorporates some different strategies in the control of delayed emesis after cisplatin.

An investigation of the efficacy and safety of a new electric interdental plaque remover for the reduction of interproximal plaque and gingivitis

This clinical study was conducted to compare the efficacy and safety of the new Braun Oral-B Interclean (ID2) with that of dental floss in healthy adults. Volunteers with sufficient dental plaque and gingivitis were randomized to use the ID2 (n = 24) or American Dental Association-approved dental floss (n = 24) in conjunction with toothbrushing once nightly for 6 weeks. All subjects received a supragingival prophylaxis and polishing at the start of the study. Over the study period, both devices produced significant reductions in interproximal plaque, gingivitis and bleeding (p < 0.01). With the ID2, there were reductions in interproximal plaque scores (all sites) of approximately 40% compared with 28% with dental floss. A decrease in gingivitis of 15% was observed with the ID2 compared with 12% for floss users. Bleeding on probing was reduced by 25% with the ID2 and by 34% with dental floss. There was a trend in favor of the ID2 with respect to reduction in plaque which achieved statistical significance (p = 0.05) for the posterior three interproximal sites. Differences between treatment groups with respect to gingivitis and bleeding reductions were not statistically significant. No adverse events were reported or observed during the study. It is concluded that the ID2 has equivalent efficacy to dental floss for the reduction of interproximal plaque and gingivitis.

Transit through the distal quarter of the oesophagus in young children

The transit time of 800 individual boluses through the distal quarter of the oesophagus was measured in 33 scintigraphic oesophageal studies which had been selected as typifying normal swallows in children. The results show that, in children, transit time through the distal quarter including the lower oesophageal sphincter is normally less than 2 seconds and that transit tends to be slower during the first 4 seconds after onset of swallowing.

Four clinical studies comparing the efficacy of flat-trim and multi-level trim commercial toothbrushes

Four independent clinical studies were conducted to compare the short- and long-term effectiveness of three commercially available toothbrushes. Two of the four studies compared plaque removal in a single-use, crossover design, and two studies compared plaque and gingivitis reduction efficacy for a long-term, three-month use. The Turesky modification of the Quigley-Hein Plaque Index and the modified Gingival Index were used to assess plaque and gingivitis levels, respectively. The two long-term studies directly compared the Oral-B P-35 and Crest Complete toothbrushes, while the two single-use studies compared the Oral-B P-35, Crest Complete and Colgate Precision toothbrushes. In all four studies, there were no significant differences found between any of the toothbrushes.

The value of the local lymph node assay in quantitative structure-activity investigations

The development of quantitative correlations between the physicochemical properties of a compound and its ability to act as a skin sensitizer is complicated by the number of variables associated with the current sensitization test data, combined with the absence of a truly objective end point. Recently, however, a novel approach to the assessment of skin sensitization potential, the local lymph node assay (LLNA), has been described, which determines the skin sensitization by measuring lymphocyte proliferation in lymph nodes draining the site of chemical exposure. The assay offers several advantages over traditional methods in the context of quantitative structure-activity relationship studies. In the present work, a range of bromoalkanes has been employed which demonstrate the robustness and reproducibility of the LLNA. Sensitizing activity increased with chain length up to a maximum at C15/C16, whereafter the response declined. The data were modelled against hydrophobicity, expressed as Clog P and (ClogP)2 to fit the biphasic nature of the results. The results demonstrate the utility of LLNA data for interpretation in the context of quantitative structure-activity relationships, the limited number of variables, inter-test reproducibility and quantitative end point, lending themselves to mathematical interpretations.

Association between glycoconjugate antibodies and Campylobacter infection in patients with Guillain-Barré syndrome

In a retrospective study, we have analysed sera from a well-characterised Guillain-Barré syndrome (GBS) patient group for antibodies that react with gangliosides. Of 95 GBS patients and 85 control patients analysed, we found that 14 (15%) of GBS patients but only one control patient had antibodies that react with the gangliosides GM1 and/or GD1b but not GM2, GD1a and GT1b using a sensitive enzyme-linked immunosorbent assay (ELISA). This pattern of reactivity suggests binding to the carbohydrate structure Gal(beta 1-3)GalNAc which is shared between some glycolipids and glycoproteins. Similar antibodies have been found previously in a subpopulation of patients with lower motor neuron disease. In the present study, the predominant immunoglobulin class of these anti-glycoconjugate antibodies was IgG rather than IgM. A correlation was found between the presence of these antibodies and prognosis in terms of disability at 3 and 12 months after presentation. Patients with anti-glycoconjugate antibodies also had a higher incidence of previous Campylobacter infections than the rest of the patient group, although the significance of this remains to be determined.

Transforming growth factor beta and noncytopathic mechanisms of immunodeficiency in human immunodeficiency virus infection

This study examines the contribution of transforming growth factor beta (TGF beta), one of the most potent endogenous immunosuppressive factors, to the development of immunodeficiency in human immunodeficiency virus (HIV) infection. Increased titers of TGF beta were found in supernatants of peripheral blood mononuclear cells (PBMCs) from HIV-infected donors as compared to uninfected controls (P less than 0.001). This correlated closely with defective responses of CD4+ lymphocytes to the recall antigens tuberculin purified protein derivative or tetanus toxoid. The addition of TGF beta-neutralizing antibody to PBMCs partially restored these defective T-cell responses. Furthermore, purified TGF beta or HIV+ PBMC culture supernatants preferentially inhibited proliferation of CD4+ lymphocytes as compared to CD8+ cells. The increased expression of the TGF beta protein was associated with increased TGF beta mRNA as determined by a polymerase chain reaction assay. This increase in TGF beta protein and mRNA was due to a selective upregulation of the TGF beta 1 isoform. These results indicate that overexpression of TGF beta 1 occurs in HIV-infected individuals and that this cytokine can contribute to impaired immune functions and to depletion of CD4+ T lymphocytes.

Antiplatelet antibody [7E3 F(ab')2] prevents rethrombosis after recombinant tissue-type plasminogen activator-induced coronary artery thrombolysis in a canine model

Coronary artery rethrombosis can complicate initially effective thrombolytic therapy. Platelets interacting with injured vascular endothelium in a region along the coronary artery with reduced luminal cross-sectional area contribute to rethrombosis. The purpose of this study was to investigate the potential of the F(ab')2 fragment of the murine monoclonal antibody 7E3 [7E3 F(ab')2] to prevent rethrombosis after intracoronary clot lysis with recombinant tissue-type plasminogen activator (rt-PA) in an experimental model. The 7E3 F(ab')2 binds to the platelet glycoprotein IIb/IIIa complex (GPIIb/IIIa), thereby preventing platelet-fibrinogen interaction and intravascular thrombus formation. Experimental coronary artery thrombosis was produced in the anesthetized dog by application of direct anodal current to the intimal surface of the left circumflex coronary artery in the region of an external stenosis. Lysis of the established intracoronary thrombus was achieved with the intravenous administration of rt-PA (25 mg) after which the animals were randomized into two groups. Group 1 (n = 10) served as the control, receiving the saline diluent, and group 2 (n = 9) received 7E3 F(ab')2, given as a single intravenous injection (0.8 mg/kg). The times required for occlusive thrombus formation, rt-PA-induced thrombolysis, and rethrombosis (if it occurred) were similar in the animals treated with saline and those treated with 7E3 F(ab')2. The initial left circumflex coronary artery blood flow was similar in both groups but decreased to a negligible level in group 1. In group 2, left circumflex coronary artery blood flow declined modestly (24 +/- 2 to 10 +/- 2 ml/min). Rethrombosis occurred in all animals in group 1 but in only two of nine animals in group 2 (p less than 0.05). Oscillations in coronary blood flow preceded rethrombosis in group 1, whereas 7E3 F(ab')2 stabilized left circumflex coronary artery blood flow patterns during the course of teh experimental protocol (5.2 +/- 0.9 vs. 0.7 +/- 0.4 oscillations, respectively; p less than 0.05). Thrombus mass recovered from the left circumflex coronary artery at the conclusion of each experiment was greater in group 1 as compared with group 2 (7.0 +/- 2.3 vs. 1.5 +/- 0.7 mg, respectively; p less than 0.05). The area of left ventricle at risk for infarction was similar in both groups but infarct size, infarction/at risk assessed histochemically, was larger in group 1 than group 2 (35 +/- 9% vs. 6 +/- 4%, respectively; p less than 0.05). Platelet aggregation induced by ADP and arachidonic acid was similar at baseline for all of the animals.(ABSTRACT TRUNCATED AT 400 WORDS)

Sustained limitation of myocardial reperfusion injury by a monoclonal antibody that alters leukocyte function

Pentobarbital anesthetized dogs were subjected to 90 minutes of left circumflex coronary artery (LCCA) occlusion followed by 72 hours of reperfusion. Control or anti-Mo1 (904) F(ab')2 fragments of monoclonal antibodies were administered intravenously at a dose of 1 mg/kg beginning 45 minutes after occlusion and at a dose of 0.5 mg/kg at 12, 24, 36, and 48 hours after reperfusion. Myocardial infarct size expressed as a percentage of the area at risk (IN/AR) measured postmortem after 72 hours of reperfusion was significantly reduced by 904 F(ab')2 (21.6 +/- 2.8%, n = 8) compared with control F(ab')2 (37.4 +/- 5.8%, n = 8; p less than 0.025). There were no significant differences between groups in heart rate, mean arterial blood pressure, rate-pressure product, or LCCA blood flow that could account for a reduced infarct size. Regional myocardial blood flow (RMBF) was determined with 15-microns radiolabeled microspheres. Transmural blood flows (ml/min/g) within the region of myocardium at risk were not statistically different between treatment groups. Infarct size in both groups was related to regional myocardial blood flow, and the relation was shifted downward in the group treated with the anti-Mo1 F(ab')2 antibody (analysis of covariance, p = 0.01). Thus, anti-Mo1 F(ab')2 produces a sustained limitation of myocardial infarct size compared with controls under similar hemodynamic conditions and a similar degree of myocardial ischemia as determined by RMBF. These data suggest that inhibition of neutrophil adhesive interactions (as suggested by the inhibitory effect of anti-Mo1 on canine neutrophil aggregation) may be an effective mechanism for protection against myocardial injury secondary to myocardial ischemia and reperfusion.

The pharmacokinetics and pharmacodynamics of a human relaxin in the mouse pubic symphysis bioassay

The effects of dose, route, regimen, and the presence or absence of a repository vehicle [benzopurpurine (BPP)] were determined for a human relaxin (hRlx) in the mouse pubic symphysis bioassay. Administration of 88 micrograms/kg hRlx sc in 1% BPP resulted in delayed, prolonged absorption. Although peak hRlx concentrations were lower, serum concentrations remained elevated longer in the presence of BPP compared to a single sc administration of hRlx in saline at the same dose. The bioavailabilities with and without BPP were similar (109 and 96%, respectively). While the pharmacodynamic effect (i.e. lengthening of the pubic ligament in estrogen-primed mice) was approximately maximum at 88 micrograms/kg hRlx sc with BPP, single sc administration of hRlx without BPP up to 264 micrograms/kg had no effect on pubic ligament length. In the absence of the BPP vehicle, manipulation of the regimen (e.g. multiple sc doses) showed that emulation of the serum concentration-time profile observed for hRlx in the presence of BPP resulted in similar pharmacodynamic effects. It appears that BPP delays the absorption of hRlx after sc administration, resulting in prolonged, elevated hRlx serum concentrations. hRlx has been shown to be effective in this model without BPP if it is administered by a multidose sc schedule. As has been observed with other protein therapeutics, the dosage regimen employed for hRlx delivery appears to be an important determinant of the expression of its pharmacodynamic effects.

EGF induces cell cycle arrest of A431 human epidermoid carcinoma cells

The human carcinoma cell line A431 is unusual in that physiologic concentrations of epidermal growth factor (EGF) inhibit proliferation. In the presence of 5-10 nM EGF proliferation of A431 cells is abruptly and markedly decreased compared to the untreated control cultures, with little loss of cell viability over a 4-day period. This study was initiated to examine how EGF affects the progression of A431 cells through the cell cycle. Flow cytometric analysis of DNA in EGF-treated cells reveals a marked change in the cell cycle distribution. The percentage of cells in late S/G2 increases and early S phase is nearly depleted. Since addition of the mitotic inhibitor vinblastine causes accumulation of cells in mitosis and prevents reentry of cells into G1, it is possible to distinguish between slow progression through G1 and G2 and blocks in those phases. When control cells, not treated with EGF, are exposed to vinblastine, the cells accumulate mitotic figures, as expected, and show progression into S, thus diminishing the number of cells in G1. In contrast, no mitotic figures are found among the EGF-treated cells in the presence or absence of vinblastine, and progression from G1 into S is not observed, as the number of cells in G1 remains constant. These results suggest that there are two EGF-induced blocks in cell cycle transversal; one is in late S and/or G2, blocking entry into mitosis, and the other is in G1, blocking entry into S phase. After 24 hours of EGF treatment, DNA synthesis is reduced to less than 10% compared to untreated controls as measured by the incorporation of [3H]thymidine or BrdU. In contrast, protein synthesis is inhibited by about twofold. Although inhibition of protein synthesis is less extensive, it occurs 6 hours prior to an equivalent inhibition of DNA synthesis. The rapid decrease in protein synthesis may result in the subsequent cell cycle arrest which occurs several hours later.