Socioeconomic position and self-rated health among adolescents: the mediating role of the family

Background

Although health inequalities in adolescence are well documented, the underlying mechanisms remain unclear. Few studies have examined the role of the family in explaining adolescents’ health inequalities. The study aimed to explore whether the association between socioeconomic position and self-rated health (SRH) was mediated by familial determinants.

Methods

Using data from wave 2 of the KiGGS study (1,838 female and 1,718 male 11- to 17-year-olds), linear regression analyses were conducted to decompose the total effects of parents’ education, occupation, income, socioeconomic position index, and adolescents’ subjective social status on SRH into direct effects and indirect effects through familial determinants (family cohesion, parenting styles, parental well-being, stress, obesity, smoking and sporting activity).

Results

A significant total effect of all socioeconomic position indicators on SRH was found, except for income in male adolescents. In female adolescents, more than 70% of the total effects of each socioeconomic position indicator were explained by familial mediators, whereas no significant direct effects remained. The most important mediator was parental well-being, followed by family cohesion, parental smoking and sporting activity. In male adolescents, the associations of parental education, the socioeconomic position index and subjective social status with SRH were also mediated by familial determinants (family cohesion, parental smoking and obesity). However, a significant direct effect of subjective social status remained.

Conclusions

The family appears to play an important role in explaining health inequalities, particularly in female adolescents. Reducing health inequalities in adolescence requires policy interventions, community-based strategies, as well as programs to improve parenting and family functioning.

Do families have moderating or mediating effects on early health inequalities? A scoping review

Background

During early childhood, families have a crucial impact on children's health behaviour, health, and development (bhd). However, a family's socioeconomic position (SEP) determines both the parental behaviour, living conditions, and child health. To understand how family characteristics may influence the development of health inequalities, this scoping review synthesised research on their mediating and moderating effects.

Methods

The review followed the guidelines of the PRISMA Extension for Scoping Reviews. The search included German and English peer-reviewed articles published between January 1st, 2000 and December 19th, 2019. The search in PubMed, PsycINFO, and Scopus used both free text terms in the title/abstract and index terms within linked keyword blocks: (1) family characteristics, (2) inequalities, (3) income, education, occupation, (4) bhd, (5) newborn, infant, toddler, preschooler. Two researchers independently examined eligibility for inclusion in two rounds (title/abstract; full-text).

Results

Of 7,089 articles identified, ten sources were included that studied family characteristics and health inequalities among 0-6 years olds. Parental rules, stress, and screentime, and TV in bedroom showed mediating effects on inequalities in behaviour problems or children's screentime. Families' negativity, single parenthood, and the number of children in the household moderated differences in impairment, health, behaviour problems, development or breastfeeding initiation.

Conclusions

The effect of family characteristics on early health inequalities has been sparsely investigated. The evidence supported models of family stress and investment. Further research is needed to comprehensively understand this association.

Key messages

Family characteristics contribute to health inequalities. Taking families’ stress and investment into account could improve targeted prevention efforts aimed at reducing health inequalities.

[Improving the quality of supervision of residents: an evaluation of supervisors using feedback by residents]

To evaluate the quality of the supervision of residents, questionnaires are frequently used.<br/> AIM: Changes in resident ratings were assessed using the validated Evaluation and Feedback for Effective Clinical Teaching (effect) questionnaire.<br/> METHOD: Supervisors (n=89) of nine medical specialities were evaluated using a validated instrument (effect). Mean overall scores (mos) and mean scale scores were compared using paired t-tests. Ten supervisors were interviewed to determine factors that stimulate or hinder improvement after an evaluation.<br/> RESULTS: The strongest increase was seen in supervisors with an mos <4.0. Motivation to improve and dialogue about the feedback stimulated improvement. Lack of time and support hindered improvement.<br/> CONCLUSION: Evaluating supervisors by providing feedback and a dialogue is suitable to improve their supervision of residents.

Effectiveness and cost-effectiveness of a guided Internet- and mobile-based intervention for the indicated prevention of major depression in patients with chronic back pain-study protocol of the PROD-BP multicenter pragmatic RCT

BACKGROUND

Reducing the disease burden of major depressive disorder (MDD) is of major public health relevance. The prevention of depression is regarded as one possible approach to reach this goal. People with multiple risk factors for MDD such as chronic back pain and subthreshold depressive symptoms may benefit most from preventive measures. The Internet as intervention setting allows for scaling up preventive interventions on a public mental health level.

METHODS

This study is a multicenter pragmatic randomized controlled trial (RCT) of parallel design aiming to investigate the (cost-) effectiveness of an Internet- and mobile-based intervention (IMI) for the prevention of depression in chronic back pain patients (PROD-BP) with subthreshold depressive symptoms. eSano BackCare-DP is a guided, chronic back pain-specific depression prevention intervention based on cognitive behavioral therapy (CBT) principles comprising six weekly plus three optional modules and two booster sessions after completion of the intervention. Trained psychologists provide guidance by sending feedback messages after each module. A total of 406 patients with chronic back pain and without a depressive disorder at baseline will be recruited following orthopedic rehabilitation care and allocated to either intervention or treatment-as-usual (TAU). Primary patient-relevant endpoint of the trial is the time to onset of MDD measured by the telephone-administered Structured Clinical Interview for DSM (SCID) at baseline and 1-year post-randomization. Key secondary outcomes are health-related quality of life, depression severity, pain intensity, pain-related disability, ability to work, intervention satisfaction and adherence as well as side effects of the intervention. Online assessments take place at baseline and 9 weeks as well as 6 and 12 months post-randomization. Cox regression survival analysis will be conducted to estimate hazard ratio at 12-month follow-up. Moreover, an economic analysis will be conducted from a societal and public health perspective.

DISCUSSION

This is the first study examining an IMI for depression prevention in a sample of chronic pain patients. If this implementation of a depression prevention IMI into orthopedic aftercare proves effective, the intervention could be integrated into routine care with minimal costs and extended for use with other chronic diseases. Results will have implications for researchers, health care providers and public health policy makers.

TRIAL REGISTRATION

The trial is registered at the WHO International Clinical Trials Registry Platform via the German Clinical Studies Trial Register (DRKS): DRKS00007960 . Registered 12 August 2015.

The influence of boot design on exercise associated surface temperature of tendons in horses

Sport horses frequently injure tendons of the lower limb. Tendon boots are commonly applied for structural support and trauma prevention during competitions. However these boots may increase heat stress in the area. Two separate studies were carried out with the aim to improve understanding of the effect of boots on heat around the tendon area. Study 1 measured heat emitted from two types of boots (traditional and perforated, cross-over design) covering the superficial digital flexor tendon in 4 horses during a set ridden and lunged exercise test. Study 2, a field test, measured the effect of boot style (traditional, perforated and open fronted) on skin surface temperature in 130 horses, after completing a cross country event test (either a BE 100 three day event or a CIC* - two day short format event). An infrared thermometer was used to measure temperatures during both studies. Boots designed with perforations demonstrated greater heat emissions than traditional (non-perforated) boots (+3.5 ° C, P<0.01). In Study 2 mean tendon surface temperature for perforated type boots (28.0 °C) was significantly lower than for traditional boots (32.3 °C) and for open fronted tendon boots (31.1 °C) (P<0.001). As this was an applied field study, additional environmental factors, such as speed and fitness level of horses, may have influenced results. Although exact mechanisms leading to these findings and the link between heat and tendon injury needs to be researched further, it is advisable to design boots to minimise tendon exposure to high temperatures, which may contribute to tendon injury.

Influence of body core temperature on blood loss and transfusion requirements during off-pump coronary artery bypass grafting: a comparison of 3 warming systems

BACKGROUND

The aim of this prospective randomized trial was to evaluate the efficacy of 3 intraoperative warming systems (Warm-Touch, Thermamed SmartCare OP system, and Allon 2001) on maintenance of normothermia and to investigate their effects on perioperative bleeding and transfusion requirements in patients undergoing off-pump coronary artery bypass grafting.

METHODS

With institutional approval/patient informed consent, 90 patients presenting for elective multiple off-pump coronary artery bypass grafting were randomly assigned to 1 of the 3 warming systems. Active warming was started after the induction of anesthesia. Perioperative transfusion was based on international guidelines. Body core temperature was recorded every 30 minutes during operation. Perioperative blood loss, autotransfusion, and allogenic transfusions were recorded. Analysis of variance was performed with post hoc Scheffé tests and chi 2 tests.

RESULTS

Normothermia could be sufficiently maintained during operation by the Allon 2001 only. Final body core temperature was 34.7 degrees C +/- 0.9 degrees C (Warm-Touch), 35.6 degrees C +/- 0.8 degrees C (Thermamed SmartCare OP), and 36.5 degrees C +/- 0.4 degrees C (Allon 2001; P < .001, Warm-Touch vs Thermamed SmartCare OP, Warm-Touch vs Allon 2001, and Thermamed SmartCare OP vs Allon 2001). Perioperative blood loss was 2683 +/- 1049 mL (Warm-Touch), 2300 +/- 788 mL (Thermamed SmartCare OP), and 1497 +/- 497 mL (Allon 2001; P = .195, Warm-Touch vs Thermamed SmartCare OP; P < .001, Warm-Touch vs Allon 2001; P = .001, Thermamed SmartCare OP vs Allon 2001). Transfusion requirements were 1097 +/- 874 mL (Warm-Touch), 986 +/- 744 mL (Thermamed SmartCare OP), and 431 +/- 387 mL (Allon 2001; P = .838, Warm-Touch vs Thermamed SmartCare OP; P = .003, Warm-Touch vs Allon 2001; P = .013, Thermamed SmartCare OP vs Allon 2001). Free of allogenic transfusion were 15 (51.7%; Warm-Touch), 18 (60%; Thermamed SmartCare OP), and 24 (82.8%; Allon 2001) patients ( P = .037).

CONCLUSIONS

The goal of normothermia during off-pump coronary artery bypass grafting was best achieved by the Allon system. With this concept, overall blood loss and transfusion requirements were reduced, hence indicating improved quality of perioperative care.

Powered vs manual tooth brushing in fixed appliance patients: a short term randomized clinical trial

Sixty-three orthodontic patients wearing upper and lower fixed appliances were randomly assigned to use either a powered toothbrush fitted with a modified orthodontic brush head (Braun Oral-B Plaque Remover 3D) or a manual toothbrush (Reach Compact Medium). A trained hygienist instructed each patient on the proper use of the allocated brush. Measurements of plaque and gingival health were made at baseline, at four weeks, and at eight weeks. Data for each group were analyzed using paired t-tests. Patients using the powered toothbrush showed a significant reduction in percentage interdental bleeding scores from baseline to four weeks (-12.7, P = .003) and this was still apparent at eight weeks (-8.6, P = .028), although there were no statistically significant changes in either plaque or gingivitis scores for this group. Those patients using a manual toothbrush showed a significant reduction in mean plaque score from baseline (four weeks = -0.18, P = < .001; eight weeks = -0.12, P = .016), but gingivitis scores were only reduced significantly at four weeks. In this group, interdental bleeding scores reduced significantly at four weeks (P = .028), but were not significantly different from baseline at eight weeks (P = .0319). When the two patient groups were compared using two sample t-tests, there were no significant differences in any of the parameters measured at any time point in the study. Over an eight-week period, there were no measurable differences between the powered toothbrush with modified orthodontic brush head and a manual toothbrush with respect to mean change in plaque, gingivitis, or interdental bleeding scores when used by patients wearing fixed appliances.

Analysis of a dehiscence zone endo-polygalacturonase in oilseed rape (Brassica napus) and Arabidopsis thaliana: evidence for roles in cell separation in dehiscence and abscission zones, and in stylar tissues during pollen tube growth

The oilseed rape (Brassica napus) endo-polygalacturonase (endo-PG) RDPG1 is involved in middle lamella breakdown during silique opening. We investigated tissue-specific expression of RDPG1 in transgenic Arabidopsis thaliana. Cellular localization of endo-PG protein in Arabidopsis siliques was determined by immuno-electron microscopy. An Arabidopsis orthologue, ADPG1, was isolated and aligned with the sequence of RDPG1. The proximal 5' sequences as well as introns are largely conserved. Analysis of the histological GUS-staining pattern of two RDPG1 promoter-GUS (beta-glucuronidase) constructs in transgenic Arabidopsis revealed that the conserved proximal part of the 5'-flanking region directs expression in dehiscence zones of siliques and anthers, floral abscission zones and stylar tissues during pollen tube growth, branch points between stems and pedicel and expression associated with the apical meristem of seedlings, while the distal part of the RDPG1 5'-flanking region contains elements involved in vascular-associated expression in petals, cotyledons and roots. Subsequent RT-PCR analysis, on RNA from the corresponding rape tissues, confirms the staining pattern revealed in transgenic Arabidopsis, thereby justifying the use of Arabidopsis as a reliable model system for analysis of oilseed rape regulatory sequences.

[The role of implicit knowledge in therapeutic change. Some implications of developmental observations for adult psychotherapy]

Several aspects of development change that are dependent on interactions between parent and infant are examined for their value in casting light on the process of change in adult psychotherapies. First, the domain of implicit knowledge (where changes necessarily occur in nonverbal infants) is identified. The vast majority of therapeutic change is found to occur in this domain. We then examine the improvised, largely unpredictable, nonlinear environments toward mutual goals that characterize the process of parent-infant and therapist-patient interactions. Finally, we provide a microdescription of these processes and provide a terminology for the "moments" that make up their flow. Of particular importance is the "moment of meeting", in which the participants interact in a way that created a new implicit, intersubjective understanding of their relationship and permits a new "way-of-being-with-the-other". We view "moments of meeting" as the key element in bringing about change in implicit knowledge, just as interpretations are thought to be the key element in bringing about change in explicit knowledge.

Inducible nitric oxide synthase expression in periodontitis

Recently, nitric oxide (NO) has been shown to be vital in inflammatory processes. Nitric oxide synthase (NOS) exists in three different isoforms, two constitutively produced with physiological roles, and an inducible form, iNOS, which is involved in inflammation. This study examined the localisation of iNOS in biopsies from patients with periodontitis using immunohistochemistry, and compared these with healthy tissue biopsies. Biopsies were obtained from 16 periodontitis patients undergoing periodontal surgery and from clinically healthy tissues of 5 patients having crown lengthening procedures. The periodontitis diseased tissue demonstrated a greater level of iNOS expression than the healthy tissue. The source of iNOS in the periodontal tissues was determined by our monoclonal antibody to be the macrophage, with the endothelial cells also contributing. A role for NO in the inflammatory response of periodontal tissues is suggested, but the precise role requires further elucidation.

GCF levels of MMP-3 and MMP-8 following placement of bioresorbable membranes

Matrix metalloproteinases (MMPs) are responsible for remodeling and degrading extracellular matrix and basement membrane components. MMP-3 and -8 levels were assessed in this study during the early healing phase following a guided tissue regeneration (GTR) procedure. 32 patients, having 2 or 3 walled intrabony defects of PD > or =6 mm, were stratified into 2 groups on the basis of age, sex, smoking status and disease severity. All intrabony defects were treated using the resorbable Guidor membrane but only 1 group of patients was given a pre-operative dosage of antibiotic (3 g amoxycillin). GCF samples for the quantification of MMP-3 and -8 levels were obtained from the intrabony site where a membrane was placed (membrane site), from the non-adjacent site on the adjacent tooth which was involved in the surgical flap (surgical control site), and from a healthy site (healthy) on the contralateral side. The GCF samples taken at baseline, 1 week, 4 weeks and 3 months after surgery were analyzed using an enzyme linked immunoabsorbent essay (ELISA) for MMP-3 and using a time-resolved immunofluorescence assay (IFMA) for MMP-8. MMP-3 was detected in a very low % of sites at baseline while relatively high levels of MMP-8 were detected at all 3 types of sites at baseline. MMP-8 levels increased for all sites at week 1, and this was statistically significant for the membrane site, but at week 4, the levels decreased for both the membrane and the surgical sites. There was no statistically significant difference between the levels of MMP-3 and -8 in the antibiotic and non-antibiotic group. Collagen remodelling occurs during the early wound healing period following surgical and regenerative procedures. The levels of MMP-3 and -8 in GCF appear to reflect these processes. Interestingly, the presence of the membranes appeared to increase the levels of MMP-3 and -8 and may relate to the resorption of the resorbable membrane by host systems.

Image homogeneity and recording reproducibility with 2 techniques for serial intra-oral radiography

The present study compared recording reproducibility and image homogeneity after applying two techniques for recording of serial intra-oral radiographs: 1) a technique previously described in 1990 based on mechanical fixation between the patient, the film holder, and the x-ray tube; and 2) a newly developed technique which operates with an optical alignment provided by a light beam. Twenty adults participated in the study. Two intra-oral radiographs were taken with a 30-minute time interval of the mandibular premolar/molar and the incisor region in each individual with either of the methods. All radiographs were scanned and digitized. Subtractions were performed between the two radiographs taken of the same individual and region with the same method. The standard deviation (SD) of the histogram defining the distribution of the grey shades in the subtraction image was used as the statistical test parameter. Subtractions were performed with an automated method and using a reference point-based program in order to test recording reproducibility and image homogeneity, respectively. Paired t-tests revealed that the average SDs obtained by the mechanical fixation method and the optical method were not statistically significantly different neither when applying the automated nor the reference point-based subtraction method (P > 0.05). The SDs increased significantly when the automated method was used compared to the reference point-based method (P = 0.001). In conclusion, the optical method and the mechanical method provided images of similar recording reproducibility and homogeneity.

The institutionalized elderly: dry to the bone!

The fluid intake of 57 elderly male and female patients, drawn from psychogeriatric, long-term care and geriatric admission units, was monitored. The fluid intake was determined by direct observation and recording of fluids consumed by each subject over three 24-hour periods. In all cases, regardless of the unit, level of dependency, cognitive or continence status, elderly patients received considerably less fluid than the recommended daily intake of 2000-2500 ml. In the case of patients who were cognitively impaired, dependent and incontinent, fluid intake was less than patients who did not have these impediments. Forty-seven nurses, working on the three units, completed a self-administered questionnaire on the fluid needs of elderly patients. Generally, nurses' knowledge was inadequate in a number of areas such as the signs and complications of dehydration and the fluid requirements of the elderly. A study of this size does not permit general conclusions to be drawn. Nonetheless, if the results are indicative of current practice, nurses do not have a good knowledge of the fluid needs of the elderly, and the low level of fluid intake constitutes a form of neglect.

Isolation and characterisation of a pod dehiscence zone-specific polygalacturonase from Brassica napus

Seven distinct partial cDNAs, similar in sequence to previously described polygalacturonases (PGs), were amplified from cDNA derived from rape pod wall, dehiscence zone and leaves by the polymerase chain reaction. Northern analysis showed that one clone, PG35-8, was expressed at low levels in the dehiscence zone during the first five weeks after anthesis but was very abundantly expressed at week 6. In contrast, no PG35-8-related RNA was detected in the pod wall. Our data suggest that there are temporal and spatial correlations between the breakdown of the middle lamella, of the dehiscence zone cells and the pattern of synthesis of PG35-8 transcripts which may indicate a role for this particular PG in rape pod dehiscence. PG35-8 was used to isolate five cDNA clones from a rape dehiscence zone cDNA library. Restriction enzyme analysis and partial sequencing revealed that they were derived from four highly homologous transcripts which are probably allelic forms of a single gene. One full-length clone, RDPG1, was completely sequenced. The predicted protein of RDPG1 showed its highest identity with PG from apple fruit with an identity of 52%.

Healing of periodontal lesions in monkeys following the guided tissue regeneration procedure. A histological study

The purpose of the present investigation was to study histologically the healing of periodontal lesions in monkeys during the first 9 weeks following periodontal reconstructive surgery according to the principle of guided tissue regeneration. Horizontal interproximal lesions and through-and-through bifurcation defects were surgically produced in 2 adult monkeys. Following removal of granulation tissue and root planing, notches indicating the level of the reduced bone level were prepared in the root surfaces. Sterile teflon membranes were then adjusted to cover the defects, and the gingival flaps were sutured in a coronally displaced position. Sacrifice of the animals was scheduled to allow for observation periods of 1, 3, 4 and 9 weeks. Evaluation of histological specimens revealed a continuous growth of new connective tissue during a period of 4 weeks. The coronal growth of new tissue did not increase significantly between 4 and 9 weeks. New cementum had formed in the most apical part of one notch after 1 week of healing, and following 3 and 4 weeks, new cementum with inserting periodontal ligament fibers were observed in all notches and to a varying degree, also more coronally on the root surfaces of both interproximal and bifurcation defects. Limited regrowth of alveolar bone was observed in the 9-week specimens. Judged from the course of the blood vessels within the newly formed connective tissue in the defects, the tissue in the central part of the defects had originated from the alveolar bone, whereas the tissue adjacent to the root surfaces seemed to have its origin in the residual periodontal ligament.

New attachment and bone formation in periodontal defects following treatment of submerged roots with guided tissue regeneration

The purpose of the present study was to examine the effect on periodontal regeneration of preventing bacterial contamination of the membrane material following the guided tissue regeneration procedure (GTR). Periodontal dehiscence defects were surgically produced in 2 monkeys. In each monkey, 8 of these defects were submerged after resection of the crowns of the teeth and a teflon (Gore-Tex Periodontal Material) or a polyglactin (Vicryl Mesh) membrane was adjusted to cover the defect and the exposed root surface. 4 defects on non-crown resected teeth were treated with either a teflon or a polyglactin membrane positioned with the coronal border approximately 2 mm below the margin of the covering tissue flap. Following 6 months of healing, the animals were sacrificed. Histological evaluation of the specimens revealed that roots which were kept completely covered during the healing period demonstrated new connective tissue attachment and bone formation corresponding to 67-100% of the length of the initial defect depth, whereas the amount of new connective tissue attachment and bone on non-submerged roots ranged between 30-59% and 11-31%, respectively. It seems reasonable to anticipate that it is bacterial contamination of the membrane material which jeopardizes the formation of new connective tissue attachment but in particular bone formation following the GTR-procedure.

Structure and expression of a nitrite reductase gene from bean (Phaseolus vulgaris) and promoter analysis in transgenic tobacco

A structural gene encoding nitrite reductase (NiR) in bean (Phaseolus vulgaris) has been cloned and sequenced. The NiR gene is present as a single copy encoding a protein of 582 amino acids. The bean NiR protein is synthesized as a precursor with an amino-terminal transit peptide (TP) consisting of 18 amino acid residues. The bean NiR transit peptide shows similarity to the TPs of other known plant NiRs. The NiR gene is expressed in trifoliate leaves and in roots of 20-day old bean plants where transcript accumulation is nitrate-inducible. Gene expression occurs in a circadian rhythm and induced by light in leaves of dark-adapted plants. A particular 100 bp sequence is present in the promoter and in the first intron of the NiR gene. Several copies of this 100 bp sequence are present in the bean genome. Comparisons between the promoter of the bean NiR gene and of two bean nitrate reductase genes (NR1 and NR2) show a limited number of conserved motifs, although the genes are presumed to be co-regulated. Comparisons are also made between the bean NiR promoter and the spinach NiR promoter. Transformation of tobacco plants with the bean NiR promoter fused to the GUS reporter gene (beta-glucuronidase) shows that the bean NiR promoter is nitrate-regulated and that the presence of the 100 bp sequence influences the level of GUS activity. NiR-coding sequences are not required for nitrate regulation but have a quantitative effect on the measured GUS activity.

A panel of monoclonal antibodies to rat plectin: distinction by epitope mapping and immunoreactivity with different tissues and cell lines

A panel of twelve monoclonal antibodies (mAbs) to plectin was analyzed to localize molecular epitopes and assess their utility for various immunotechniques. Based on staining patterns obtained by immunoblotting of proteolytic plectin fragments five groups of mAbs with spatially closely linked epitopes were distinguished. In combination with previous results obtained with recombinant mutant proteins, the epitopes of all mAbs could be shown to reside within three separated domains of plectin's rod domain. Immunoblot analyses of several different rat tissues and a number of cultured cell lines derived from various species, including rat, hamster, cow, mouse and man, revealed considerable variations in immunoreactivity of antibodies. Differences in mAb immunoreactivities were also revealed by immunofluorescence microscopy of different tissues and cultured cell lines. One third of the mAbs examined produced staining patterns that were indistinguishable from those generated by conventional rabbit antisera, confirming the widespread and highly divers cellular localization of plectin previously reported. Microinjection of several monoclonal antibodies into Rat 1 cells had no detectable effects on the structure and organization of plectin arrays or of other cytoskeletal filaments. This new collection of mAbs provides a more reliable tool for histological studies than previously available antisera and should be useful for studies of tissue and cell type specific functions of plectin domains in vivo and in vitro.

Effect of local metronidazole application on periodontal healing following guided tissue regeneration. Clinical findings

The effect of periodontal healing after guided tissue regeneration (GTR) in association with local application of metronidazole gel was evaluated in this study. Twelve patients with one pair of vertical periodontal bone defects of comparable size and configuration participated in the study. In a matched paired design, the test defects were treated by GTR using expanded polytetrafluoroethylene (ePTFE) membranes in combination with local application of metronidazole gel. The controls were treated in the same way except for application of metronidazole. During the first month of membrane implantation, no statistically significant differences between test and control surfaces were noted with respect to inflammation of the marginal gingiva. Six weeks following insertion, the membranes were removed. Six months after removal of the membrane, the median gain in probing attachment level as a percentage of the initial defect depth was 92% for test defects and 50% for control defects (P = .001). No statistically significant differences were found between test and control sites regarding plaque, bleeding on probing, reduction in pocket depth, gain in bone height, or recession of the gingival margin. In conclusion, the results of the present study indicate that local application of metronidazole gel has a beneficial effect on healing of periodontal vertical defects treated by guided tissue regeneration.

Effect of local metronidazole application on periodontal healing following guided tissue regeneration. Microbiological findings

The bacteriological colonization of healing periodontal defects was investigated after treatment with guided tissue regeneration using expanded polytetrafluoroethylene membranes together with local metronidazole gel (25%, 250 mg/g). Twelve patients, each with one pair of comparable defects, had the test defect treated with the membrane plus metronidazole gel and the control defect treated with the membrane alone. Thirty weeks after removal of the membrane, the median gain in probing attachment level as a percentage of the initial defect depth was 92% for the test defects and 50% for the control defects (P = 0.001). The median number of cultivable bacteria decreased from 1.2 x 10(6) at the presurgical examination to 3.0 x 10(5) at the one week examination in the test group (P = 0.02), whereas an increase was observed in the control group. Similarly, a lower median proportion of black-pigmented Gram-negative anaerobic rods was observed one week postsurgically in the test group (0.004%) compared to the control group (3.5%) (P = 0.02). Two weeks after membrane insertion, and at all following examinations, no microbiological differences between test and control group were observed. Consequently, the influence of the metronidazole gel on the treatment result appears to have been confined to the initial regeneration phase. Despite the good clinical results in the test group, all membranes from both test and control pockets were heavily colonized with bacteria at the time of removal. To ensure maximal periodontal regeneration with formation of bone, future research in this area should concentrate on reducing the microbial colonization of the wound area.

Monoclonal antibody mapping of structural and functional plectin epitopes

To map structural and functional epitopes of the cytomatrix protein plectin, a set of mAbs was prepared by immunization of mice. Using immunoblot analysis of plectin fragments obtained after limited digestion with various proteases, two groups of mAbs were distinguished. The epitopes of one group (1) were located on a 130-kD terminal segment of the plectin 300-kD polypeptide chain, whereas those of the other group (2) bound within a 40kD segment confined to a central domain of the polypeptide chain. Domains containing the epitopes of group 2 mAbs were shown to include in vitro phosphorylation sites for kinase A, whereas kinase C phosphorylation sites were found on the same terminal segment that contained group 1 mAb epitopes. Rotary shadowing EM of mAb (Fab fragment) -decorated plectin molecules at various states of aggregation, ranging from characteristic dumbbell-shaped single molecules to highly complex multimeric structures, revealed that the epitopes of group 1 as well as those of group 2 mAbs were located on plectin's roughly 200-nm long rod domain interlinking its two globular end domains. Epitopes of group 1 mAbs were localized within a region near the center of the rod, those of group 2 in more peripheral sections near the globular end domains. Solid-phase binding assays carried out in the presence of Fab fragments of mAbs demonstrated an interference of certain group 1 mAbs in the interactions of plectin with vimentin and lamin B. On the other hand, plectin's self-interaction was inhibited mainly by Fab fragments with epitopes in the peripheral rod domain (group 2 mAbs). Together, these results suggested that the molecular binding sites of plectin for vimentin and lamin B, as well as the phosphorylation sites for kinase C, were confined to a defined central section of plectin's rod domain. In addition, they suggest an involvement of peripheral rod sections in plectin self-association.

The sleep state characteristics of apnea during infancy

The sleep state characteristics of infant sleep apnea were studied in 36 twins examined by polygraphy at 40, 44, and 52 weeks after conception. The definition of sleep apnea is dependent upon the length of apnea, sleep state, and post-conceptional age. None of the infants had apnea longer than 20 seconds and apnea of 10 seconds or longer was uncommon. The attack rates for apneas 2 to 4.9 seconds long were highest in REM and lowest in qliet sleep. The attack rates for apneas 5 to 9.9 seconds long were equal in REM and indeterminate and lowest in quiet sleep. The percentage of infants with apnea of 10 seconds or longer at 40 weeks was highest in REM (27%) and indeterminate sleep (42%) and lowest in quiet sleep (12%). At 52 weeks, apnea 10 seconds or longer during REM decreased to 0%. The effect of maturation on apnea varies with sleep state. Over the period from 40 to 52 weeks, quiet sleep apnea was unchanged and indeterminate sleep apnea decreased only between 40 and 44 weeks. Although REM apnea 2 to 4.9 seconds long was unchanged, REM apnea 5 to 9.9 seconds long decreased between 40 and 44 weeks, and REM apnea of 10 seconds or longer decreased from 27% at 40 weeks to 0% at 52 weeks. This suggests that semi-independent apnea turn-on and turn-off mechanism operate during REM sleep. A correlation between brief apneas and the longer apneas was seen only during REM sleep. For all sleep states, there was no correlation between the levels of apnea of 5 seconds or longer at 40, 44, and 52 weeks.