What is occlusion?

The aim of this series of papers is to explore the role of occlusion in dental practice. The range of opinion in the dental profession as to the importance of occlusion is enormous. It is very important that the profession in general and practising dentists in particular have a balanced view of occlusion. This is more important than every patient having a balanced occlusion. The fact that the study of occlusion is characterised by extremes makes it confusing and possibly difficult for individual dentists to find a philosophy which is in line with contemporary good practice supported by evidence from practice-based research.

Correct condom application among African-American adolescent females: the relationship to perceived self-efficacy and the association to confirmed STDs

PURPOSE

To assess condom application ability and the relationship between perceived ability and demonstrated ability. Also, to examine the association between high-demonstrated condom application ability and recent sexual risk behaviors and laboratory-diagnosed sexually transmitted diseases (STDs) among African-American adolescent females.

METHODS

A purposeful sample of sexually active African-American females (n = 522) completed a structured interview and provided vaginal swab specimens for STD testing. Subsequent to the interview, adolescents demonstrated their condom application skills using a penile model. A 9-item scale assessed adolescents' perceived self-efficacy to apply condoms. Sexual risk behaviors assessed by interview were noncondom use at last intercourse and the last five intercourse occasions for steady and casual sex partners as well as any unprotected vaginal sex in the past 30 days and the past 6 months.

RESULTS

Approximately 28% of the sample tested positive for at least one STD and nearly 26% self-reported a history of STDs. Controlled analyses indicated that adolescents' self-efficacy for correct use was not related to demonstrated skill. Adolescents' demonstrated ability was not related to any of the sexual risk behaviors. Likewise, recent experience applying condoms to a partner's penis and demonstrated ability were not related to laboratory-diagnosed STDs or self-reported STD history.

CONCLUSIONS

Adolescents may unknowingly be at risk for human immunodeficiency virus and STD infection owing to incorrect condom application. Further, high-demonstrated ability to apply condoms was not related to safer sex or STDs. Reducing sexual risk behaviors may require more than enhancing adolescent females' condom application skills and may require addressing other relational skills.

The role of different immunosuppression in the long-term histological outcome of HCV reinfection after liver transplantation for HCV cirrhosis

BACKGROUND

The effect of the type of immunosuppression on the course of posttransplant hepatitis C virus (HCV) infection is unclear. The aim of this study was to evaluate the histological outcome of posttransplant HCV infection with respect to initial immunosuppressive therapy in a cohort of 59 of 65 HCV positive transplant patients who survived at least 12 months.

METHODS

Initial immunosuppressive therapy was triple (cyclosporine or tacrolimus and azathioprine and prednisolone) in 41, double (cyclosporine and prednisolone) in 5, and single (cyclosporine or tacrolimus) in 13 patients. There was blinded histological evaluation, based on necroinflammatory activity (grading score:0-18) and fibrosis (staging score: 0-6). The median histological follow-up was 36 (12-72) months.

RESULTS

In the last liver biopsy, high necroinflammatory activity indicating chronic hepatitis (grading score > or =4) was found in 42 (71%) and severe fibrosis or cirrhosis (staging score > or =4) in 18 (30.5%) patients. High necroinflammatory activity was associated significantly with absence of pretransplant alcohol abuse (P=0.01) and relatively with occurrence of posttransplant acute lobular hepatitis C (P=0.055). Development of severe fibrosis or cirrhosis was significantly associated only with the type of initial immunosuppressive therapy. In particular, severe fibrosis or cirrhosis developed significantly more frequently in patients treated with triple or double (17/46 or 37%) than with single initial immunosuppressive therapy (1/13 or 7.7%) (adjusted for biopsy time: P=0.045).

CONCLUSIONS

Severe fibrosis or cirrhosis appears to develop in 30% of HCV transplant patients in a median of 3 years and to be associated with heavier initial immunosuppression.

Correlates of adolescent females' worry about undesired pregnancy. the importance of partner desire for pregnancy

STUDY OBJECTIVE

The purpose of this study was to determine correlates of worry about pregnancy among a high-risk sample of low-income African-American adolescent females. Specifically, we tested the hypothesis that perceived male partner desire for pregnancy and level of sexual communication would be independently associated with adolescent females' worry about becoming pregnant.

DESIGN

A survey of sexually active African-American adolescent females, 14-18 years of age.

SETTING

Recruitment was conducted in low-income neighborhoods of Birmingham, Alabama, characterized by high rates of unemployment, substance abuse, violence, and teen pregnancy.

PARTICIPANTS

Adolescents (N = 522) completed a survey and a face-to-face interview, and provided a urine specimen for pregnancy testing.

MAIN OUTCOME MEASURE

Nonpregnant adolescents reporting steady relationships with a male sex partner (over the past 6 months) and indicating no immediate desire to become pregnant were included in the analysis (n = 196). Two questionnaire items assessed level of worry about becoming pregnant.

RESULTS

Compared to adolescent females reporting their partner did not desire pregnancy, those perceiving their partner desired pregnancy were nearly three times more likely to experience high worry about becoming pregnant (AOR = 2.85; P =.009). Engaging in sex unprotected by a condom was an equally important correlate of high worry (AOR = 2.84; P =.013). Level of communication between partners about pregnancy prevention was not significant.

CONCLUSIONS

Adolescent females may experience high worry about becoming pregnant due to desires of their male partner as well as their recent sexual risk behavior.

Photocytotoxicity of lipofuscin in human retinal pigment epithelial cells

Lipofuscin accumulates with age in a variety of highly metabolically active cells, including the retinal pigment epithelium (RPE) of the eye, where its photoreactivity has the potential for cellular damage. The aim of this study was to assess the phototoxic potential of lipofuscin in the retina. RPE cell cultures were fed isolated lipofuscin granules and maintained in basal medium for 7 d. Control cells lacking granules were cultured in an identical manner. Cultures were either maintained in the dark or exposed to visible light (2.8 mWcm2) at 37 degrees C for up to 48 h. Cells were subsequently assessed for alterations in cell morphology, cell viability, lysosomal stability, lipid peroxidation, and protein oxidation. Exposure of lipofuscin-fed cells to short wavelength visible light (390-550 nm) caused lipid peroxidation (increased levels of malondialdehyde and 4-hydroxy-nonenal), protein oxidation (protein carbonyl formation), loss of lysosomal integrity, cytoplasmic vacuolation, and membrane blebbing culminating in cell death. This effect was wavelength-dependent because light exposure at 550 to 800 nm had no adverse effect on lipofuscin-loaded cells. These results confirm the photoxicity of lipofuscin in a cellular system and implicate it in cell dysfunction such as occurs in ageing and retinal diseases.

How should airways resistance be measured in young children: mask or mouthpiece?

The reproducibility and acceptability of airways resistance measurements using the interrupter technique (MicroRint) obtained using a mouthpiece were compared with those using a face mask. Fifty children aged 4-7 yrs performed four sets of six Rint measurements; two using a mouthpiece and two using a face mask with integral mouthpiece. Complete data were obtained from 45 (90%) children using the mouthpiece and 43 (86%) children using the mask. The two methods were equally repeatable with comparable intraclass correlation coefficients (ICC) and coefficients of variation. Mean Rint values obtained using the mouthpiece were significantly lower than those using the face mask ((mean+/-SD) mouthpiece=0.81+/-0.18 kPa x L(-1) x s, mask=0.88+/-0.24 kPa x L(-1) x s p=0.0002). Although the mean paired differences between the two methods were small (0.07 kPa x L(-1) x s), the ICC and limits of agreement confirmed that the two methods could not be used interchangeably. Sixty-seven per cent of children preferred the face mask but this was more time-consuming (p = 0.03). Children did not produce more repeatable results using their preferred method, nor did they improve with practice. Repeatable airway resistance measurements using the interrupter technique can be obtained from young children using either a mouthpiece or a face mask, but there are significant clinical and statistical differences between the results obtained.

Parental monitoring: association with adolescents' risk behaviors

CONTEXT

Contemporary threats to adolescents' health are primarily the consequence of risk behaviors and their related adverse outcomes. Identifying factors associated with adolescents' risk behaviors is critical for developing effective prevention strategies. A number of risk factors have been identified, including familial environment; however, few studies have examined the impact of parental monitoring.

OBJECTIVE

To examine the influence of less perceived parental monitoring on a spectrum of adolescent health-compromising behaviors and outcomes. Design. Survey.

SETTING

A family medicine clinic. Participants. To assess eligibility, recruiters screened a sample of 1130 teens residing in low-income neighborhoods. Adolescents were eligible if they were black females, between the ages of 14 and 18 years, sexually active in the previous 6 months, and provided written informed consent. Most teens (n = 609) were eligible, with 522 (85.7%) agreeing to participate.

MAIN OUTCOME MEASURES

Variables in 6 domains were assessed, including: sexually transmitted diseases, sexual behaviors, marijuana use, alcohol use, antisocial behavior, and violence.

RESULTS

In logistic regression analyses, controlling for observed covariates, adolescents perceiving less parental monitoring were more likely to test positive for a sexually transmitted disease (odds ratio [OR]: 1.7), report not using a condom at last sexual intercourse (OR: 1.7), have multiple sexual partners in the past 6 months (OR: 2.0), have risky sex partners (OR: 1.5), have a new sex partner in the past 30 days (OR: 3.0), and not use any contraception during the last sexual intercourse episode (OR: 1.9). Furthermore, adolescents perceiving less parental monitoring were more likely to have a history of marijuana use and use marijuana more often in the past 30 days (OR: 2.3 and OR: 2.5, respectively); a history of alcohol use and greater alcohol consumption in the past 30 days (OR: 1.4 and OR: 1.9, respectively); have a history of arrest (OR: 2.1); and there was a trend toward having engaged in fights in the past 6 months (OR: 1.4).

CONCLUSIONS

The findings demonstrate a consistent pattern of health risk behaviors and adverse biological outcomes associated with less perceived parental monitoring. Additional research needs to focus on developing theoretical models that help explain the influence of familial environment on adolescent health and develop and evaluate interventions to promote the health of adolescents.

Evaluation of a new selective medium for methicillin-resistant Staphyloccocus aureus

The aims of this study were to evaluate the performance of a new medium, desferrioxamine oxacillin tellurite egg-yolk mannitol salt agar (DOTEMSA) in detecting methicillin-resistant Staphylococcus aureus (MRSA) and then to compare this medium against the Public Health Laboratory Service (PHLS) recommendation of mannitol salt agar (Oxoid) with oxacillin (OMSA) and Baird-Parker medium with ciprofloxacin (BPC) for the isolation of MRSA. The individual selective agents contained in DOTEMSA were tested against isolates of coagulase-negative staphylococci (CNS) and the medium with all constituents was challenged with various bacteria. Routine screening specimens were plated out on OMSA, BPC and DOTEMSA and the plates were incubated and examined at 24 and 48 h. Tellurite, desferrioxamine and oxacillin each inhibited the majority of CNS isolates; only three (of 103) grew in the presence of all three agents. Sixty-two of 63 isolates of MRSA grew on DOTEMSA and 59 produced lipase. Most other bacteria were inhibited. In all, 184 MRSA isolates were isolated from 540 screening specimens. The sensitivity of OMSA, BPC and DOTEMSA was 42%, 81% and 51% at 24 h, and 60%, 89% and 89% at 48 h. At 48 h, the combination of BPC and DOTEMSA detected 99% of MRSA isolates. Seventy, 49 and one non-MRSA isolates needed investigation for each of the three media respectively. A proposed strategy for MRSA screening would use BPC and DOTEMSA, examining BPC at 24 h and both media at 48 h. Provisional reports could then be issued at 24 h on the basis of rapid agglutination tests to confirm isolates as S. aureus from BPC and at 48 h on the basis of typical colonies from DOTEMSA.

Exposure to X-rated movies and adolescents' sexual and contraceptive-related attitudes and behaviors

OBJECTIVES

To examine the association between exposure to X-rated movies and teens' contraceptive attitudes and behaviors.

METHODS

Black females, 14 to 18 years old (n = 522) were recruited from adolescent medicine clinics, health departments, and school health clinics.

RESULTS

Exposure to X-rated movies was reported by 29.7% of adolescents. Exposure to X-rated movies was associated with being more likely to have negative attitudes toward using condoms (odds ratio [OR]: 1.4), to have multiple sex partners (OR: 2.0), to have sex more frequently (OR: 1.8), to not have not used contraception during the last intercourse (OR: 1.5), to have not used contraception in the past 6 months (OR: 2.2), to have a strong desire to conceive (OR: 2.3), and to test positive for chlamydia (OR: 1.7).

CONCLUSIONS

Additional research is needed to understand the impact of X-rated movies on adolescents' sexual and contraceptive health.

The effects of repetitive physiologic loading on bone turnover and mechanical properties in adult female and male rats

Repetitive physiologic loading is widely believed to be beneficial in maintaining skeletal integrity. However, repetitive loading is also associated with bone injuries, including stress fractures and osteoporotic fractures, indicating that under certain conditions repetitive physiologic loading decreases the functional capacity of bone. Our objective was to identify the response of bone to excessive repetitive loading in adult rats. Male and female rats (8-9 months old) were exposed to 2 hours of treadmill running each day for 10 or 30 consecutive days. We examined bone response using biochemical, densitometric, and monotonic, relaxation, and cyclic mechanical outcomes. Urinary deoxypyridinoline, a marker of bone resorption, was not significantly affected by running nor were tibial or femoral bone mineral density (BMD) (P > 0.05). Tibial mechanical properties following running were not decreased (P > 0.05). We did observe a slight decrease in displacement to failure (P < 0.05) and energy to failure (P = 0.10) of the proximal femur. These findings indicate that 14,000 physiologic loading cycles per day did not increase systemic bone resorption levels or substantially degrade the mechanical properties of long bone in adult rats. The lack of response to low magnitude, high cycle number physiologic loading is consistent with the view that a metabolic bone disturbance, in addition to repetitive loading, may be necessary for the development of the stress injury in the adult skeleton.

A new 'online' method to measure increased exhaled isoprene in end-stage renal failure

BACKGROUND

Isoprene is the most abundant hydrocarbon present in breath, and recent reports indicate that breath concentrations increase following haemodialysis. The purpose of this study was to establish whether selected ion flow tube mass spectrometry (SIFT-MS), a newly established technique in breath analysis, may be used to quantify breath isoprene in haemodialysis patients in the clinical setting. SIFT-MS is compared and contrasted with the established gas chromatography mass spectrometric technique for this purpose.

METHODS

Three consecutive exhalations from 19 haemodialysis patients (12 males, seven females) undergoing a morning dialysis shift were analysed just prior to commencing treatment. Within 5 min of completing their usual dialysis regimen, using polysulphone membranes, the breath of each patient was analysed again. Additional contemporary samples were obtained from 17 normal controls. Breath isoprene was quantified using SIFT-MS, a method previously validated quantitatively using neat isoprene.

RESULTS

Successful measurements of breath isoprene were obtained for each subject within 2 min, with minimum disruption to a busy dialysis environment. The coefficient of variation of triplicate measurements of breath isoprene was <10%. Prior to dialysis, the mean (+/-SD) breath isoprene concentration (138+/-63 parts per billion (ppb)) was significantly greater than for normal controls (89+/-36 ppb; P=0.016). Immediately following treatment, breath isoprene increased significantly to 184+/-95 ppb (P=0.023).

CONCLUSIONS

SIFT-MS permits the accurate and rapid measurement of breath isoprene in haemodialysis patients in the clinical setting. The previously reported increase in breath isoprene following dialysis treatment is confirmed. SIFT-MS is the ideal analytical tool to investigate this phenomenon further.

Acute tonsillitis complicated by retropharyngeal and thyroid abscess infected with de-repressed beta lactamase Citrobacter mutans

An unusual presentation of acute tonsillitis complicated by retropharyngeal and thyroid abscess is reported. Spontaneous rupture of retropharyngeal abscess resulted in necrotic fistulae between the pharyngeal wall and the retropharyngeal space.

Methicillin-resistant Staphyloccocus aureus: evaluation of five selective media

This study evaluates the performance in isolating methicillin-resistant Staphylococcus aureus (MRSA) of three media: the reduced salt formulation of mannitol salt agar plus oxacillin (MMSAO); CHROMagar Staph aureus plus ciprofloxacin (CHRAC); and Halifax MRSA medium (HMO), against the previously recommended mannitol salt agar (7% salt) plus oxacillin (OMSAO) and Baird-Parker medium plus ciprofloxacin (BPC). MRSA screening swabs were plated out onto the five selective media and the plates examined at 24 and 48 h. Suspected colonies were confirmed as MRSA by detection of heat-labile DNase, coagulase and/or protein A, and by confirming resistance to methicillin. Of 719 specimens examined, 191 grew MRSA on at least one medium. The relative sensitivities of the five media at 48 h were as follows: BPC, 94%; CHRAC, 70%; OMSAO, 61%; HMO, 56%; and MMSAO, 46%. In addition, BPC gave the least number of unnecessary investigations for non-MRSA isolates. The current advantage of BPC when performing direct culture for MRSA was confirmed. The other ciprofloxacin-containing medium also produced reasonable results. Of the two mannitol salt agar media, the formulation with 7% salt gave better results. HMO proved unreliable at isolating MRSA.

Hamstrings vs. patella tendon for anterior cruciate ligament reconstruction: a randomised controlled trial

A randomised controlled trial was performed to evaluate early outcome for two types of anterior cruciate ligament reconstruction. Sixty patients undergoing cruciate reconstruction were randomized into two groups. Group PT underwent reconstruction using a patella tendon autograft, whereas Group (SG) had a semitendinosus/gracilis autograft (SG). IKDC, Lysholm, and Tegner scores, KT1000 values and muscle strength were recorded pre-operatively, at 6 months and 1 year follow up. The functional scores, activity level, muscle strength and anterior tibial translation improved in both groups. No significant difference between groups was found for any measurement at 6 months and 1 year despite adequate study power. The study indicates that the 1 year results for either technique are equally favourable.

Amniotic fluid embolus: a review of the literature

PURPOSE

To review the literature since 1979 to determine the natural history, etiology, diagnosis and potential treatment of amniotic fluid embolus (AFE).

SOURCE

English language articles and books published between June 1976 and June 1998 were identified by a computerized medline search using the title or text word amniotic fluid embolus. This same search strategy was repeated and updated to October 1999 by an independent individual using both Medline and Embase. The search was also expanded to include Science Citation Index listing Morgan's 1979 review article. All relevant publications were retrieved and their bibliographies were scanned for additional sources.

PRINCIPAL FINDINGS

Randomized controlled trials are not possible with amniotic fluid emboli. The majority of the literature consists of clinical reports combined with occasional limited reviews. Knowledge obtained from these reports suggests that amniotic fluid emboli present as a spectrum of disease that ranges from a subclinical entity to one that is rapidly fatal. Because cases are sporadic and the diagnosis is often unconfirmed, little progress has been made towards understanding its etiology or defining the risk factors. Present management is empirical and directed towards the maintenance of oxygenation, circulatory support and the correction of coagulopathy.

CONCLUSION

Amniotic fluid embolus continues to be a life-threatening but potentially reversible complication unique to pregnancy. It cannot be predicted nor prevented. Review of the literature reveals that there are no standardized investigational methods or protocols to confirm the diagnosis in suspected cases.

Equity of service: a protocol for management of children with speech problems

In an attempt to achieve equity of service, the level of consistency of speech and language therapists in making decisions about the management of children with phonological delay was examined. Six cases were created and the therapists were interviewed about their management and criteria for therapy for each case. Decisions were made about standardising practice within the team. A phonological care pathway was devised to consider the criteria outlined in the results. This pathway is now being piloted with the expectation that it will facilitate an equitable service for all children with sound system problems.

Early outcomes of supervised discharge

We have previously described the generally positive initial experiences of Supervised Discharge (SD) in a large Mental Health Trust serving a mixed inner city, suburban and rural population. This paper seeks to extend our earlier findings by reporting a longitudinal cohort study examining hospitalization before and after SD for the original sample. The main outcome measures were: renewal of SD; time spent out of hospital; survival to readmission or the end of the study period (1 April 1999). Of the 22 patients commenced on SD orders between April 1996 and October 1997, by 1 April 1999: 12 patients were still subject to supervised discharge; 15 had not been readmitted to hospital; survival out of hospital was longer--717 days, compared with 607 days in the same period before SD (p = 0.037); survival to readmission was also longer than before SD (p = 0.023). Contrary to early professional expectations patients subject to SD seem to survive for longer periods in the community. Although not always effective, its wider use should at least be considered as part of the care package for detained patients with a history of non-compliance with care packages leading to relapse and readmission.