Efficacy of a dentifrice containing zinc citrate for the control of plaque and gingivitis: a 6-month clinical study in adults

The objective of this 6-month, double-blind, clinical study, conducted in harmony with American Dental Association (ADA) guidelines, was to evaluate the efficacy of a dentifrice containing 2% zinc citrate and 0.76% sodium monofluorophosphate in a silica base (zinc citrate dentifrice) for the control of supragingival plaque and gingivitis, compared to a control dentifrice containing 0.76% sodium monofluorophosphate in a silica base (control dentifrice). Adult men and women from the Atlanta, Georgia, area were entered in the study and stratified into two treatment groups, which were balanced for baseline Quigley-Hein Plaque Index scores and baseline Löe-Silness Gingival Index scores. Participants received an oral prophylaxis and were instructed to brush their teeth twice daily (morning and evening) for 1 minute with their assigned dentifrice, using a soft-bristled toothbrush. Examinations for supragingival plaque and gingivitis were conducted after 3 months and again after 6 months' use of the study dentifrices. Ninety-nine participants complied with the protocol and completed the entire 6-month clinical study. At both the 3- and 6-month study examinations, the zinc citrate dentifrice group exhibited statistically significant reductions in both plaque and gingivitis compared to the control dentifrice group, based on whole-mouth data. At the 6-month examination, the magnitude of these reductions met or exceeded 18% for both plaque and gingivitis (25.3% for plaque; 18.8% for gingivitis). The effect of the zinc citrate dentifrice was most pronounced on the more severe manifestations of plaque and gingivitis, indicating a statistically significant (50.2%) reduction in severe plaque and a statistically significant (66.7%) reduction in severe gingivitis over the control dentifrice after 6 months of use. Similar findings were observed for data obtained from proximal, lingual, and posterior sites. Among the sites that indicated a tendency toward high levels of plaque or gingivitis based on the baseline scores, substantially fewer sites tended to continue to present such high levels at follow-up exams in the zinc citrate dentifrice group than in the control dentifrice group. Thus, in accordance with the 1986 guidelines published by the ADA and the 1994 revision published by the Task Force on Design and Analysis in Dental and Oral Research, the results of this study support the conclusion that a dentifrice containing 2% zinc citrate and 0.76% sodium monofluorophosphate in a silica base is clinically efficacious for the control of supragingival plaque and gingivitis.

The benefits and application of the Lyofoam product range

Foam dressings are used widely by many healthcare professionals. They provide an excellent healing environment for exuding wounds. Lyofoam is a polyurethane foam dressing that has been developed over the last few years and is available in a variety of presentations for light, moderately, and heavily exuding wounds. A new addition to complement the Lyofoam range is Lyofoam Extra Adhesive. Lyofoam is a well established and clinically proven wound dressing.

An investigation of the benefits of Aquacel Hydrofibre wound dressing

Aquacel wound dressing, produced by ConvaTec, uses the main ingredient of the hydrocolloid dressing in a new way to produce a hydrofibre dressing. Aquacel is designed for use in moderate to heavily exuding wounds as it absorbs exudate directly into its fibres. It has been shown to be effective in pressure sores, leg ulcers and surgical wounds, producing warm, moist, local wound conditions for optimum wound healing. Aquacel can lock exudate away thus protecting the surrounding skin.

Muscular soreness following prolonged intermittent high-intensity shuttle running

The aim of this study was to examine the impact of prolonged intermittent high-intensity shuttle running on soreness and markers of muscle damage. Sixteen males took part in the study, half of whom were assigned to a running group and half to a resting control group. The exercise protocol involved 90 min of intermittent shuttle running and walking (Loughborough Intermittent Shuttle Test: LIST), reflecting the activity pattern found in multiple-sprint sports such as soccer. Immediately after exercise, there was a significant increase (P < 0.05) in serum activities of creatine kinase and aspartate aminotransferase, and values remained above baseline for 48 h (P < 0.05). Median peak activities of creatine kinase and aspartate aminotransferase occurred 24 h post-exercise and were 774 and 43 U x l(-1), respectively. The intensity of general muscle soreness, and in the specific muscles investigated, was greater than baseline for 72 h after the shuttle test (P < 0.05), peaking 24-48 h post-exercise (P < 0.05). Muscle soreness was not correlated with either creatine kinase or aspartate aminotransferase activity. Soreness was most frequently reported in the hamstrings. Neither soreness nor serum enzyme activity changed in the controls over the 4 day observation period. It appears that unaccustomed performance of prolonged intermittent shuttle running produces a significant increase in both soreness and markers of muscle damage.

p53 Mutations in lung cancer associated with residential radon exposure

Unusual mutation patterns in lung tumors among underground miners have been indicated, suggesting radon-specific alterations in the genome, but the data are not consistent. To investigate the association between residential radon exposure and p53 mutations in lung tumors, we performed a study on cases from a nation-wide population-based investigation in Sweden. Our study included 83 nonsmoking lung cancer cases and 250 smoking lung cancer cases, diagnosed 1980-1984, with a time-weighted average radon exposure over 140 Bq/m3 or up to 50 Bq/m3. Radon was measured in dwellings occupied by the study subjects at some time since 1947. Information on smoking habits and other risk factors was obtained from questionnaires. After exclusions because of the initiation of treatment or insufficient material, the p53-status of 243 tumors was determined using PCR-single-stranded conformation polymorphism analysis and sequencing determination of exons 5-8. The overall mutation prevalence was 23.9%. An increased mutation prevalence was suggested among those with high exposure to residential radon [odds ratio (OR), 1.4; 95% CI, 0.7-2.6], especially among nonsmokers (OR, 3.2; 95% CI, 0.7-15.5), but no specific mutational pattern was indicated. Furthermore, the mutation prevalence seemed to be higher among smoking lung cancer cases than among nonsmoking cases (OR, 2.1; 95% CI, 0.9-5.0), and particularly among those smoking less than 10 cigarettes per day. It may be concluded that residential exposure to radon seems to contribute to a higher mutation prevalence of the p53 gene in lung tumors.

The management of patients with venous leg ulcers: new guidelines

The RCN Institute, the Centre for Evidence-based Nursing, and the University of York have recently produced guidelines on the management of patients with venous leg ulcers. These guidelines make recommendations with regard to assessment, compression therapy, cleansing, debridement, dressings, contact sensitivity, training/education and quality assurance (Cullum et al, 1998). They are evidence-based (Effective Health Care Bulletin, 1997), have been informed by expert opinion and are reflective of current good clinical practice. It is envisaged that they will be updated every 2 years. This article provides an outline of these guidelines. However, healthcare professionals must note that guidelines can simplify clinical decision making and this must be acknowledged when the guidelines' recommendations for practice are being implemented.

Algosteril calcium alginate dressing for moderate/high exudate

Algosteril is a new alginate dressing manufactured by Les Laboratoires BROTHIER and distributed by Beiersdorf Medical. It is a natural, pure, non-woven dressing made from calcium alginate fibres. It complements other products in the Beiersdorf wound care family such as Cutinova, Cutifilm and Cutisorb. Algosteril rapidly absorbs and retains wound fluid to form an integral gellified structure, thereby maintaining an ideal moist wound healing environment. It traps and immobilizes pathogenic bacteria in the network of gellified fibres, stimulates macrophage activity and activates platelets, resulting in haemostasis and accelerated wound healing.

Generation of neutralizing human monoclonal antibodies against parvovirus B19 proteins

Infections caused by human parvovirus B19 are known to be controlled mainly by neutralizing antibodies. To analyze the immune reaction against parvovirus B19 proteins, four cell lines secreting human immunoglobulin G monoclonal antibodies (MAbs) were generated from two healthy donors and one human immunodeficiency virus type 1-seropositive individual with high serum titers against parvovirus. One MAb is specific for nonstructural protein NS1 (MAb 1424), two MAbs are specific for the unique region of minor capsid protein VP1 (MAbs 1418-1 and 1418-16), and one MAb is directed to major capsid protein VP2 (MAb 860-55D). Two MAbs, 1418-1 and 1418-16, which were generated from the same individual have identity in the cDNA sequences encoding the variable domains, with the exception of four base pairs resulting in only one amino acid change in the light chain. The NS1- and VP1-specific MAbs interact with linear epitopes, whereas the recognized epitope in VP2 is conformational. The MAbs specific for the structural proteins display strong virus-neutralizing activity. The VP1- and VP2-specific MAbs have the capacity to neutralize 50% of infectious parvovirus B19 in vitro at 0.08 and 0.73 microgram/ml, respectively, demonstrating the importance of such antibodies in the clearance of B19 viremia. The NS1-specific MAb mediated weak neutralizing activity and required 47.7 micrograms/ml for 50% neutralization. The human MAbs with potent neutralizing activity could be used for immunotherapy of chronically B19 virus-infected individuals and acutely infected pregnant women. Furthermore, the knowledge gained regarding epitopes which induce strongly neutralizing antibodies may be important for vaccine development.

Marijuana use among minority youths living in public housing developments

Youths residing in public housing developments appear to be at markedly heightened risk for drug use because of their constant exposure to violence, poverty, and drug-related activity. The purpose of this study was to develop and test a model of marijuana etiology with adolescents (N = 624) residing in public housing. African-American and Hispanic seventh graders completed questionnaires about their marijuana use, social influences to smoke marijuana, and sociodemographic and psychosocial characteristics. Results indicated that social influences, such as friends' marijuana use and perceived ease of availability of marijuana, significantly predicted both occasional and future use of marijuana. Individual characteristics such as antimarijuana attitudes and drug refusal skills also predicted marijuana use. The findings imply that effective prevention approaches that target urban youths residing in public housing developments should provide them with an awareness of social influences to use marijuana, correct misperceptions about the prevalence of marijuana smoking, and train adolescents in relevant psychosocial skills.

Large-pore hemodialysis in acute endotoxin shock

OBJECTIVE

This study was undertaken to test the hypothesis that hemodialysis with a large-pore membrane would improve heart function during acute endotoxin shock.

SETTING

Large animal laboratory.

DESIGN

Eighteen mongrel dogs were instrumented to measure left ventricular maximum end-systolic elastance (left ventricular maximum elastance at end systole), cardiac output, circumflex artery blood flow, and myocardial mechanical efficiency (CO x MAP/MVO2, where CO is cardiac output, MAP is mean arterial pressure, and MVO2 is myocardial oxygen consumption). Plasma catecholamine concentrations were determined by high-performance liquid chromatography. Endotoxin shock was induced by infusing 5.0 microg/kg/min of Escherichia col 0127:B8 endotoxin in the portal vein for 60 mins, followed by 2.0 microg/kg/min of constant infusion. Control dogs (n = 6) received 4.0 mL/kg/min of saline; hemodialysis dogs (n = 6) underwent venovenous hemodialysis in 50-min intervals using a polysulfone filter (1.2 m2; mean pore size, 0.50 nm; blood flow rate, 400 mL/min; ultrafiltrate, "zero-balanced"); shams (n = 5) were treated identically to hemodialysis dogs, except that no convective dialysis was performed. A fourth group (n = 6) was treated with dopamine (5.0-7.0 microg/kg/min, optimal dose for contractile increase based on dose-response studies).

MEASUREMENTS AND MAIN RESULTS

After 2 hrs of treatment, left ventricular maximum elastance at end systole increased and was unchanged in controls (30 +/- 5 mm Hg/mm) and shams (24 +/- 6 mm Hg/mm) compared with basal control. Hemodialysis treatment increased contractility (53 +/- 4 mm Hg/mm), as did dopamine treatment (54 +/- 7 mm Hg/mm). Endotoxin shock reduced mechanical efficiency to 45% of basal control; with hemodialysis treatment, left ventricular efficiency returned to 64% of basal control measurement, compared with 49% with dopamine treatment. During treatment, myocardial glucose uptake was increased with hemodialysis compared with other groups. No difference was observed among groups for left ventricular end-diastolic pressures or dimensions, or catecholamine concentrations.

CONCLUSIONS

Large-pore hemodialysis increased left ventricular contractility to a similar degree as dopamine and provided a marginal improvement in myocardial glucose uptake and mechanical efficiency.

Psychosocial predictors of cigarette smoking among adolescents living in public housing developments

BACKGROUND

Adolescents residing in low-income public housing developments in inner-city regions may be particularly vulnerable to a variety of risk factors associated with cigarette smoking.

OBJECTIVE

To elucidate the aetiology of cigarette smoking among adolescents living in public housing developments.

DESIGN, SETTING, AND SUBJECTS

We examined predictors of smoking from four domains: background characteristics, social influences, behavioural control, and psychosocial characteristics using a sample of seventh graders (mean age 12.9 years) who reside in public housing developments in New York City (n = 624). The addresses of participants in a larger investigation of the aetiology and prevention of smoking were checked to determine if they lived in one of 335 public housing developments in New York City. All participants living in public housing developments were included in the current study.

MAIN OUTCOME MEASURES

African-American and Hispanic students completed questionnaires about their cigarette use, social pressures to smoke, smoking attitudes, smoking knowledge, and smoking resistance skills. Students also provided information on demographic and behavioural control (such as church and school attendance).

RESULTS

Logistic regression analyses indicated that social influences from friends and family members predicted smoking. Psychosocial characteristics such as advertising resistance skills, anti-smoking attitudes, and refusal skills lowered the odds of smoking.

CONCLUSIONS

These findings suggest that smoking prevention approaches targeted at these young people should increase their awareness of social pressures to smoke, correct misperceptions about the prevalence of smoking among friends, and teach relevant psychosocial skills.

Influence of high and low glycemic index meals on endurance running capacity

PURPOSE

The purpose of this study was to examine the effect of high and low glycemic index (GI) carbohydrate (CHO) pre-exercise meals on endurance running capacity.

METHODS

Eight active subjects (five male and three female) ran on a treadmill at approximately 70% VO2max to exhaustion on two occasions separated by 7 d. Three hours before the run after an overnight fast, each subject was given in a single-blind, random order, isoenergetic meal of 850+/-21 kcal (mean+/-SEM; 67% carbohydrate, 30% protein, and 3% fat) containing either high (HGI) or low (LGI) GI carbohydrate foods providing 2.0 g CHO.kg(-1) body weight.

RESULTS

Ingestion of the HGI meal resulted in a 580% and 330% greater incremental area under the 3-h blood glucose and serum insulin response curves, respectively. Performance times were not different between the HGI and LGI trials (113+/-4 min and 111+/-5 min, respectively). During the first 80 min of exercise in the LGI trial, CHO oxidation was 12% lower and fat oxidation was 118% higher than in the HGI trial. Although serum insulin concentrations did not differ between trials, blood glucose at 20 min into exercise in the HGI trial was lower than that during the LGI trial at the same time (3.6+/-0.3 mmol.L(-1) vs 4.3+/-0.3 mmol.L(-1); P < 0.05). During exercise, plasma glycerol and serum free fatty acid concentrations were lower in the HGI trial than in the LGI trial.

CONCLUSIONS

This results demonstrate that although there is a relative shift in substrate utilization from CHO to fat when a low GI meal is ingested before exercise compared with that for a high GI meal, there is no difference in endurance running capacity.

The gastrointestinal bacteria of mink (Mustela vison L): influence of age and diet

Total numbers of aerotolerant and anaerobic bacteria, and densities of Enterobacteriaceae, lactobacilli, staphylococci, salmonella and shigella, and campylobacteria were enumerated in the contents of the stomach, small intestine (and the associated mucosa), and colon of mink beginning at 2 weeks of age to adulthood, and in adults that were fed diets with different levels and types of fiber or food deprived. Highest densities of all bacterial groups were found in the colon at all ages (up to 10(8) cfu per g for total anaerobes), but were 2-4 orders of magnitude lower than those of other mammals. When all regions were pooled, significant age-related increases (p < 0.05) were detected for anaerobes, aerobes, and staphylococci, and these coincided with the dietary shift at weaning. Enterobacteriaceae did not vary with age. Lactobacilli were never common isolates, but were detected more often after weaning, particularly in adults fed diets containing the 2 sources of fiber. Campylobacteria were detected only at 2 weeks of age, and salmonella and shigella were not isolated from any of the experimental mink. Total bacterial densities, the relative proportions of the bacterial groups, and age- and diet-related effects differ from those known for other mammals, which may be related to the carnivorous diet and rapid movement of digesta through the GIT.

In ovo vaccination technology

More than 80% of the U.S. broiler industry has converted to the in ovo vaccination process for control of Marek's disease. Providing certain criteria are met, including timing and site of vaccine placement, vaccine mixing, machine sanitization, and hatchery management specifications, this has proven to be an efficacious and convenient method of vaccination. Efforts to extend the technology for other viral vaccines including Newcastle, bronchitis and bursal disease, and bacterial and parasitic vaccines are in progress. Collectively, these studies demonstrate that in ovo vaccination technology using approved vaccine is a safe, efficacious, and convenient method for vaccination of poultry.

SL1 trans splicing and 3'-end formation in a novel class of Caenorhabditis elegans operon

Many Caenorhabditis elegans genes exist in operons in which polycistronic precursors are processed by cleavage at the 3' ends of upstream genes and trans splicing 100 to 400 nucleotides away, at the 5' ends of downstream genes, to generate monocistronic messages. Of the two spliced leaders, SL1 is trans spliced to the 5' ends of upstream genes, whereas SL2 is reserved for downstream genes in operons. However, there are isolated examples of what appears to be a different sort of operon, in which trans splicing is exclusively to SL1 and there is no intercistronic region; the polyadenylation signal is only a few base pairs upstream of the trans-splice site. We have analyzed the processing of an operon of this type by inserting the central part of mes-6/cks-1 into an SL2-type operon. In this novel context, cks-1 is trans spliced only to SL1, and mes-6 3'-end formation occurs normally, demonstrating that this unique mode of processing is indeed intrinsic to this kind of operon, which we herein designate "SL1-type." An exceptionally long polypyrimidine tract found in the 3' untranslated regions of the three known SL1-type operons is shown to be required for the accumulation of both upstream and downstream mRNAs. Mutations of the trans-splice and poly(A) signals indicate that the two processes are independent and in competition, presumably due to their close proximity, raising the possibility that production of upstream and downstream mRNAs is mutually exclusive.

Effect of milk on somatostatin degradation in suckling rat jejunum in vivo

BACKGROUND

Somatostatin-14 is present in breast milk, and intact somatostatin-14 has been recovered from gastric lumen of infants. Studies have shown that somatostatin-14 is metabolized in the intestinal luminal contents in vitro, which could be prevented by the presence of breast milk. In this study, the effect of milk on stability of somatostatin-14 in suckling rat jejunum in vivo was examined.

METHODS

125I-Somatostatin-14[Tyr 11] was administered to the isolated jejunal loops in anesthetized suckling rats in the absence or presence of milk, fractions of milk, or known protease-peptidase inhibitors. Structural integrity of 125I-somatostatin-14[Tyr 11] recovered from tissues at different intervals was analyzed by gel filtration and high-performance liquid chromatography.

RESULTS

Radioactivity rapidly disappeared from the jejunal lumen with a 50% clearance achieved by 1.2 minutes. Gel filtration and high-performance liquid chromatography analyses showed that 125I-somatostatin- 14[Tyr 11] was rapidly degraded into smaller fragments. At 1 minute, jejunal luminal radioactivity was eluted in a major peak with retention time of 42.4 minutes, along with other minor peaks (retention time, 5.6, 8.0, 10.4, and 14.4 minutes); only a trace amount of intact 125I-somatostatin-14[Tyr 11] (retention time, 44.8 minutes) was present. Coadministration of rat's milk or its soluble fraction increased the level of intact 125I-somatostatin-14[Tyr 11] in the jejunal lumen and jejunal tissue. Presence of rat's milk-casein or peptidase inhibitors (bestatin, phosphoramidon, or Bowman-Birk inhibitor), however, failed to increase the level of intact 125I-somatostatin-14[Tyr 11].

CONCLUSION

These results suggest that somatostatin-14 is rapidly degraded in the jejunal lumen of suckling rats, and that milk-borne peptidase inhibitors prevent this somatostatin-14 degradation.

Persistence of self in advanced Alzheimer's disease

PURPOSE

To determine if evidence of the persistence of a sense of self or personal identity could be found in people in the middle and late stages of Alzheimer's disease. The theme of diminishing self pervades both the popular and professional literature on Alzheimer's disease.

DESIGN

Qualitative using conversational analysis. The purposive sample was 23 residents of two urban nursing homes in the southeastern United States who were in the middle and late stages of Alzheimer's disease. Their mean Mini-Mental State examination score was 10.65. Nineteen subjects were women, four were men in this 1993-1997 study.

METHODS

Analysis of 45 conversations lasting 30 minutes with nursing home residents with a diagnosis of probable Alzheimer's disease. Use of the first person indexical and other evidence, such as awareness and reactions to the changes that had taken place, in support of and counter to the notion of persistence of self, were sought in conversational analysis.

FINDINGS

Respondents used the first person indexical frequently, freely, and coherently. Evidence was also present that participants were aware of their cognitive changes. Many struggled to provide an explanation, but none mentioned Alzheimer's disease.

CONCLUSIONS

Evidence suggests the persistence of awareness of self into the middle and late stages of Alzheimer's disease. Failure to recognize the continuing awareness of self and the human experience of the person in the middle and late stages can lead to task-oriented care and low expectations for therapeutic interventions. The bafflement noted in respondents suggests that people should be told their diagnosis and offered an explanation of what this diagnosis means.

Binary quantitative structure-activity relationship (QSAR) analysis of estrogen receptor ligands

The use of high throughput screening (HTS) to identify lead compounds has greatly challenged conventional quantitative structure-activity relationship (QSAR) techniques that typically correlate structural variations in similar compounds with continuous changes in biological activity. A new QSAR-like methodology that can correlate less quantitative assay data (i.e., "active" versus "inactive"), as initially generated by HTS, has been introduced. In the present study, we have, for the first time, applied this approach to a drug discovery problem; that is, the study of the estrogen receptor ligands. The binding affinities of 463 estrogen analogues were transformed into a binary data format, and a predictive binary QSAR model was derived using 410 estrogen analogues as a training set. The model was applied to predict the activity of 53 estrogen analogues not included in the training set. An overall accuracy of 94% was obtained.

Long-term outcome analysis of two treatment methods for cleft palate: combined levator retropositioning and pharyngeal flap versus double-opposing Z-plasty

OBJECTIVE

Two surgical techniques for repair of a cleft palate include levator retropositioning in combination with a pharyngeal flap and the Furlow double-opposing Z-plasty. This study compared morbidity and speech results from the use of these two methods in an effort to determine which was the superior technique.

DESIGN

Patient records from 1986 to 1996 were retrospectively reviewed, and 10 patients with a cleft palate who underwent repair with a levator retropositioning and pharyngeal flap were compared to 14 patients who underwent a double-opposing Z-plasty repair. Postoperative complications including fistula formation, obstructive sleep apnea, and residual velopharyngeal insufficiency were recorded. Speech was assessed perceptually and through the use of nasometry.

RESULTS

Both surgical techniques resulted in good speech in the majority of patients. Only two patients in the study, both in the Z-plasty group, had severe postoperative hypernasality. Two patients in the levator retropositioning and pharyngeal flap group developed severe postoperative obstructive sleep apnea, requiring additional surgery.

CONCLUSION

The levator retropositioning and pharyngeal flap technique was successful in achieving good speech results, but it also caused more serious postoperative complications when compared to the double-opposing Z-plasty technique.

Broken past, fragile future: personal stories of high-risk adolescent mothers

PURPOSE

To uncover what adolescent mothers view as their childhood struggles, their transition to the role of motherhood following a childhood of abuse/neglect, and their important relationships after they became parents.

DESIGN

Qualitative, phenomenological.

SETTING

Community-based parenting program for first-time mothers at risk for abusing or neglecting their children.

PARTICIPANTS

Seven first-time mothers, ages 13 to 20, who reported they had been abused and/or neglected as children. All had healthy newborns.

RESULTS

Five themes emerged from the data: impoverished past, disintegration of relationships, emotional distance, problem fixing, and reconnecting. Participants described a process of using the experience of pregnancy and parenting as a mechanism for growth. Becoming a parent provided an opportunity to receive support from family members and to build more positive relationships. They viewed the experience as a second chance for a successful and fulfilling life.