Natural history of periodontal disease in man. Rapid, moderate and no loss of attachment in Sri Lankan laborers 14 to 46 years of age

This paper describes the initiation, rate of progress of periodontal disease and consequent tooth loss in a population never exposed to any programs or incidents relative to prevention and treatment of dental diseases. The group consisted of 480 male laborers at two tea plantations in Sri Lanka. The study design and baseline data have been published. At the initial examination in 1970, the age of the participants ranged between 14 and 31 years. Subsequent examinations occurred in 1971, 1973, 1977, 1982 and 1985. Thus, the study covers the age range 14-46 years. Throughout the study, the clinical indices were scored by the same two examiners, both well-trained and experienced periodontitis. Intra-examiner reproducibility for each index was tested at baseline and repeated periodically during the study. The data for each examination were computerized and updated on an ongoing basis. At the last examination in 1985, there were 161 individuals who had participated in the first survey. This population did not perform any conventional oral hygiene measures and consequently displayed quite uniformly large aggregates of plaque, calculus and stain on their teeth. Virtually all gingival units exhibited inflammation. Based on interproximal loss of attachment and tooth mortality rates, three subpopulations were identified: (1) individuals (approximately 8%) with rapid progression of periodontal disease (RP), those (approximately 81%) with moderate progression (MP), and a group (approximately 11%) who exhibited no progression (NP) of periodontal disease beyond gingivitis. At 35 years of age, the mean loss of attachment in the RP group was approximately 9 mm, the MP group had approximately 4 mm and the NP group had less than 1 mm loss of attachment. At the age of 45 years, the mean loss of attachment in the RP group was approximately 13 mm and the MP group approximately 7 mm. The annual rate of destruction in the RP group varied between 0.1 and 1.0 mm, in the MP group between 0.05 and 0.5 mm, and in the NP group between 0.05 and 0.09 mm. Since this population was virtually caries free, essentially all missing teeth were lost due to periodontal disease. In the RP group, tooth loss already occurred at 20 years of age and increased throughout the next 25 years. At 35 years of age, 12 teeth had been lost, at 40 years of age 20 teeth were missing and at 45 all teeth were lost. In the MP groups, tooth mortality started after 30 years of age and increased throughout the decade.(ABSTRACT TRUNCATED AT 400 WORDS)

Post-translational processing of proopiomelanocortin in the pituitary and in the brain

Proopiomelanocortin (POMC) is a neuropeptide precursor molecule which is translocated to the secretory pathway within neuroendocrine cells. It is cleaved by the action of endopeptidases to yield mature peptides like adrenocorticotrophic hormone (ACTH), beta-lipotrophin (beta-LPH), beta-endorphin. In this review we present evidence on the cleavage specificities and structure of endoproteases which cleave neuropeptide precursors at pairs of basic amino acids and on the identity and mode of action of exopeptidases. This information is derived from cloning of their corresponding cDNAs and subsequent expression within neuroendocrine cells; and also from biochemical studies. We discuss the intracellular targeting and sorting mechanisms of POMC within neuroendocrine cells. We also examine the tissue-specific post-translational processing of POMC within the anterior and intermediate lobes of the pituitary gland and within the central nervous system.

A pilot study of a Mediterranean-type diet intervention in female patients with rheumatoid arthritis living in areas of social deprivation in Glasgow

BACKGROUND

A Mediterranean-type diet rich in fish, fruit and vegetables and low in saturated fats has been associated with health benefits, including improved cardiovascular profile and benefit in RA.

OBJECTIVE

To overcome obstacles to healthy eating by a community-based intervention promoting a Mediterranean-type diet in patients with RA living in socially deprived areas of Glasgow.

METHODS

130 female patients with RA aged 30-70 years (median 55), disease duration 8 years were recruited from three hospital sites. The intervention group (n = 75) attended weekly 2-hour sessions for 6 weeks in the local community, including hands-on cooking classes backed up with written information. The control group (n = 55) were given dietary written information only. Both groups completed food frequency questionnaires (FFQs), and clinical and laboratory measures were assessed at baseline, 3 and 6 months.

RESULTS

Significant benefit was shown in the intervention group compared with controls for patient global assessment at 6 months (p = 0.002), pain score at 3 and 6 months (p = 0.011 and 0.049), early morning stiffness at 6 months (p = 0.041) and Health Assessment Questionnaire score at 3 months (p = 0.03). Analysis of the FFQs showed significant increases in weekly total fruit, vegetable and legume consumption and improvement in the ratio of monounsaturated:saturated fat intake and systolic BP in the intervention group only. The cooking classes were positively received by patients and tutors; cost/patient for the 6 week course was 84 pounds (124 euro).

CONCLUSIONS

Results demonstrate that a 6 week intervention can improve consumption of healthier foods. If implemented more widely it may prove a popular, inexpensive and useful adjunct to other RA treatment.

Immunosuppressive effects of radiation on human dendritic cells: reduced IL-12 production on activation and impairment of naive T-cell priming

Dendritic cells (DC) are professional antigen-presenting cells (APC) of the immune system, uniquely able to prime naive T-cell responses. They are the focus of a range of novel strategies for the immunotherapy of cancer, a proportion of which include treating DC with ionising radiation to high dose. The effects of radiation on DC have not, however, been fully characterised. We therefore cultured human myeloid DC from CD14+ precursors, and studied the effects of ionising radiation on their phenotype and function. Dendritic cells were remarkably resistant against radiation-induced apoptosis, showed limited changes in surface phenotype, and mostly maintained their endocytic, phagocytic and migratory capacity. However, irradiated DC were less effective in a mixed lymphocyte reaction, and on maturation produced significantly less IL-12 than unirradiated controls, while IL-10 secretion was maintained. Furthermore, peptide-pulsed irradiated mature DC were less effective at naive T-cell priming, stimulating fewer effector cells with lower cytotoxicity against antigen-specific targets. Hence irradiation of DC in vitro, and potentially in vivo, has a significant impact on their function, and may shift the balance between T-cell activation and tolerization in DC-mediated immune responses.

Lack of radiological and clinical benefit over two years of low dose prednisolone for rheumatoid arthritis: results of a randomised controlled trial

BACKGROUND

Evidence for disease modifying activity of low dose corticosteroid treatment in rheumatoid arthritis is contradictory. Studies showing radiological benefit suggest that continued treatment is required to sustain the effect.

OBJECTIVE

To evaluate the effect of low dose oral prednisolone in early rheumatoid arthritis on disease activity over two years.

DESIGN

Double blind placebo controlled trial.

METHODS

Patients with rheumatoid arthritis, duration <3 years (n = 167), were started on a disease modifying antirheumatic drug (DMARD; sulphasalazine) and allocated by stratified randomisation to prednisolone 7 mg/day or placebo. Primary outcome measure was radiological damage, assessed by the modified Sharp method. Clinical benefit was a secondary outcome. A proactive approach to identifying and treating corticosteroid adverse events was adopted. Patients who discontinued sulphasalazine were offered an alternative DMARD.

RESULTS

90 of 257 patients eligible for the study refused to participate (more women than men). Of those enrolled, 84% were seropositive for rheumatoid factor, median age 56 years, median disease duration 12 months, female to male ratio 1.8:1. Prednisolone was given to 84 patients; of these 73% continued prednisolone and 70% sulphasalazine at 2 years. Of the 83 patients on placebo, 80% continued placebo and 64% sulphasalazine at 2 years. There were no significant differences in radiological score or clinical and laboratory measures at 0 and 2 years.

CONCLUSIONS

Low dose prednisolone conferred no radiological or clinical benefit on patients maintained on a DMARD over two years. Low dose corticosteroids have no role in the routine management of rheumatoid arthritis treated with conventional disease modifying drugs.

Effect of disease modifying agents on the lipid profiles of patients with rheumatoid arthritis

OBJECTIVE

To determine the effect of intramuscular gold and oral hydroxychloroquine (HCQ) on the lipid profile of patients with rheumatoid arthritis (RA).

METHOD

A prospective randomised clinical trial of 12 months' duration was performed in 100 RA patients. Data on clinical and laboratory parameters of disease activity, and fasting serum lipid samples was collected at baseline and at three monthly intervals over one year.

RESULTS

The expected second line response was seen with no significant difference in efficacy between the groups at 12 months. The HCQ group had a significant overall improvement in their lipid profile while there was a trend for lipid profiles in the gold group to worsen.

CONCLUSIONS

HCQ is an effective second line agent that has beneficial effects on serum lipids. This should be taken into account when choosing a disease modifying anti-rheumatic drug in patients who suffer from RA and who have significant cardiovascular risk factors.

Bird and bat predation services in tropical forests and agroforestry landscapes

Understanding distribution patterns and multitrophic interactions is critical for managing bat- and bird-mediated ecosystem services such as the suppression of pest and non-pest arthropods. Despite the ecological and economic importance of bats and birds in tropical forests, agroforestry systems, and agricultural systems mixed with natural forest, a systematic review of their impact is still missing. A growing number of bird and bat exclosure experiments has improved our knowledge allowing new conclusions regarding their roles in food webs and associated ecosystem services. Here, we review the distribution patterns of insectivorous birds and bats, their local and landscape drivers, and their effects on trophic cascades in tropical ecosystems. We report that for birds but not bats community composition and relative importance of functional groups changes conspicuously from forests to habitats including both agricultural areas and forests, here termed 'forest-agri' habitats, with reduced representation of insectivores in the latter. In contrast to previous theory regarding trophic cascade strength, we find that birds and bats reduce the density and biomass of arthropods in the tropics with effect sizes similar to those in temperate and boreal communities. The relative importance of birds versus bats in regulating pest abundances varies with season, geography and management. Birds and bats may even suppress tropical arthropod outbreaks, although positive effects on plant growth are not always reported. As both bats and birds are major agents of pest suppression, a better understanding of the local and landscape factors driving the variability of their impact is needed.

Trial of brief intermittent neuroleptic prophylaxis for selected schizophrenic outpatients: clinical and social outcome at two years

OBJECTIVE

To evaluate a novel approach to the prophylaxis of schizophrenic relapse characterised by administration of brief courses of neuroleptic for the earliest non-psychotic signs of relapse (prodromal symptoms).

DESIGN

Two year follow up of subjects randomised, double blind, to receive either active (control group) or placebo (intermittent group) depot neuroleptic medication. Both groups received brief courses of oral neuroleptic when prodromal symptoms or relapse occurred.

SETTING

Psychiatric outpatient department, Charing Cross Hospital, London.

SUBJECTS

54 Stable patients in remission who met the American Psychiatric Association's DSM-III criteria for schizophrenia on the basis of case notes.

MAIN OUTCOME MEASURES

Survival without relapse, survival without hospitalisation, point prevalence of extrapyramidal side effects and tardive dyskinesia, structured assessment of social functioning (social adjustment scale II), and frequency of prodromal symptoms.

RESULTS

Of 19 relapses recorded over two years, 10 (53%) were preceded by non-psychotic prodromal signs. Survival rates for both relapse and hospitalisation were worse with intermittent treatment than continuous treatment over the two year follow up: 92% of controls and only 54% of patients given intermittent treatment survived the two year period without hospitalisation. Prolonged or frequent relapses as well as episodes of prodromal symptoms were more frequent with intermittent treatment. Lower scores for extrapyramidal side effects were recorded in the intermittent treatment group, but periodic assessments of social functioning failed to show any social advantages from this.

CONCLUSION

The findings are at variance with a previous report of one year follow up in this cohort and attest to the superiority of continuous depot neuroleptic prophylaxis in preventing both psychotic and neurotic or dysphoric morbidity in schizophrenia.

Systematic errors in estimating prevalence and severity of periodontal disease

Partial-mouth scores are often used in epidemiologic studies to estimate the prevalence and severity of periodontal disease. Such estimates systematically underestimate the prevalence of disease, but the bias can be in either direction for disease severity. Three large data sets containing full-mouth examinations (mesiobuccal, midbuccal, distobuccal, and midlingual (MBDL) sites per tooth) for either attachment loss or probing pocket depths were used to investigate the magnitudes of systemic error that occur by employing four specific partial-mouth scores (M, MB, MBD, and MBDL sites per tooth), which are based on the random half-mouth technique. For prevalence of disease the sensitivity of a partial score was a function of the disease level in the population. All four partial scores were sensitive enough to adequately portray true prevalence using the 2-mm demarcation value, the MBD and MBDL scores might still be considered adequate for the 4-mm value, but none of these partial scores were adequate for the 7-mm value. For disease severity the MBDL score produced unbiased estimates, the others were biased. The relative biases for the MB and MBD scores were all under 10% (in absolute value), but the M score produced severe relative biases, 24% for probing pocket depths and -12% for attachment loss.

The role of early versus late removal of GTAM membranes on bone formation at oral implants placed into immediate extraction sockets. An experimental study in dogs

The purpose of this study was to compare the effect of early versus late removal of expanded polytetrafluoroethylene (e-PTFE) membranes on bone formation at oral implants. Thirty Brånemark fixtures were placed into immediate extraction sockets with buccal bone dehiscences augmented by e-PTFE membranes. At 4 weeks, the membranes and underlying soft tissues were removed from 5 implants, but at 16 sites only the membranes were extirpated. In 9 sites, the membranes remained in place during the healing period. Sixteen weeks after fixture insertion, the sites in which the membrane was retained (MRET) showed an average of 5.2 mm of clinical bone height increase (100% of bone fill). For sites where the membrane together with underlying soft tissues were removed (MRB), the corresponding value was 2.0 mm (42% of bone fill). Implants at which only the membrane was removed (MR) showed the least clinical bone height increase (1.0 mm), resulting in 21% coverage of original threads. Histometric measurements verified that the MRET sites had the least distance from the top of the fixture to the newly formed bone level (0.4 mm). However, in contrast with the clinical findings, the histometric analyses showed that the MRB group had the greatest remaining bone defect (3.3 mm). The clinical and histometric results of the MRET group were statistically better, though, compared with those of the other two groups. Biopsies, removed from beneath the membranes, revealed slightly inflamed connective tissue, containing spicules of newly formed bone, indicating that more bone might have been created if the membranes had been retained longer.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of results following three modalities of periodontal therapy related to tooth type and initial pocket depth

Results following three modalities of periodontal therapy (subgingival curettage, modified Widman flap surgery, and pocket elimination or reduction surgery) in 78 patients over 8 years were compared for variations in pocket depth and clinical attachment level related to tooth types (maxillary molars, mandibular molars, maxillary biscupids, mandibular biscupids, maxillary anterior teeth, mandibular anterior teeth). The analysis was based on a classification of three severity groups according to initial crevice or pocket depth (Class I, 1-3 mm; Class II, 4-6 mm; and Class III, 7-12 mm) and with patient's means of measurements being the experimental units for the statistical analysis. Reduction in pocket depth and gain of clinical attachment for pockets 4 mm or deeper occurred following all three methods of treatment, and was well sustained over 8 years. No one modality of treatment was consistently superior to any of the other two with regards to sustained reduction of pocket depth and gain of clinical attachment. Surgical pocket elimination or reduction did not enhance the prognosis for maintenance of periodontal support in either moderate or advanced periodontal lesions anywhere in the mouth compared with more conservative modalities of treatment. In spite of prophylaxis and instruction in home care every 3 months, there was a slight progressive loss of attachment over time in areas of shallow crevices (1-3 mm).

A longitudinal study comparing scaling, osseous surgery, and modified Widman procedures: results after 5 years

BACKGROUND

Scaling and root planing, osseous surgery, and modified Widman procedures are effective methods for treating periodontal diseases. Studies have been carried out to determine if these procedures are more effective than others in reducing clinical probing depths, while maintaining clinical attachment levels. The purpose of this report is to present 5-year results from a longitudinal study comparing scaling and root planing (SRP), osseous surgery (OS), and modified Widman (MW) therapies. The study has been completed for 12 years.

METHODS

Sixteen adult patients with moderate to advanced periodontal disease were treated with initial scaling and oral hygiene procedures in a private practice. Posthygiene data were used to compare changes in plaque and gingival indices, probing depth (PD), clinical attachment levels (CAL), and recession. Frequency distributions were used to compare changes at individual sites. The first published report was from baseline to one year. This follow-up report is from baseline through 5 years.

RESULTS

At 5 years, there were significant decreases in gingival and plaque scores. For the 3 procedures, there were significant decreases in baseline 4 to 6 mm PD (P<0.0001); however, there were no differences between the methods. Similar findings were noted for PD initially greater than 7 mm. At 5 years, OS had the greatest number of 1 to 3 mm sites (332 sites, 73.2%), while MW had the fewest number of 4 to 6 mm PD (98 sites, 21.8%). SRP had the fewest 7 mm and greater sites (15 sites, 3.4%). At 5 years, CAL loss for 1 to 3 mm PD was statistically significant for the 3 procedures. There were slight gains in CAL for 4 to 6 mm probing depths. These gains were not significant. Similar findings were seen for CAL for probing depths greater than 7 mm. OS had the greatest number of sites losing more than 2 mm of CAL (64 sites), followed by SRP (21 sites) and MW (34 sites), respectively.

CONCLUSIONS

This 5-year clinical trial demonstrates that with good patient maintenance excellent clinical results can be achieved with various methods of treatment. Within the limits of this study, SRP, OS, and MW were effective at reducing probing depths with slight changes in clinical attachment levels.

The effects of guided bone regeneration and grafting on implants placed into immediate extraction sockets. An experimental study in dogs

Guided bone regeneration (gbr) for the treatment of insufficient bone volume around implants can be performed using membranes with or without grafting materials (i.e., autogenous, allogenous, xenogenous, or alloplastic grafts). A possible way to evaluate the quality of implant osseointegration is the torque necessary to remove implants from their bony housing. The aim of this study was to compare the torques necessary to remove dental implants from implant beds reconstructed with different bone substitutes and GBR or GBR alone in 6 adult mongrel dogs. All mandibular premolars were extracted and 3 extraction sockets on each side were enlarged using a trephine bur. A 13 mm titanium screw-type dental implant (3.75 mm diameter) was placed in each enlarged extraction socket so that only the apical 3 to 4 mm were engaged in bone. The 3 defects were then randomly treated with either 1) canine demineralized freeze-dried bone allograft (DFDBA) plus GBR using an expanded polytetrafluoroethylene membrane (DFDBA+GTAM); 2) bioabsorbable hydroxyapatite and GBR (HA+GTAM); or 3) GBR (GTAM alone). After 6 months, the torque to remove the implants was measured in 4 animals and analyzed using ANOVA. There were no statistically significant differences between the 3 groups (GTAM alone: 46.37+/-16.41 Ncm; HA+GTAM: 46.00+/-16.59 Ncm; DFDBA+ GTAM: 52.15+/-29.24 Ncm). In addition, the influence of early removal of barriers on the torque values was evaluated with the t-test. Comparing exposed versus retained membranes by treatment modality, the only statistically significant difference was found in the DFDBA+GTAM group. When the torque values of all implants with exposed and retrieved membranes were compared to all those with retained membranes a significant difference could be detected. Histologic sections were prepared from the 2 dogs not included in the removal torque testing. In the histometric analysis the GTAM alone group showed a mean mineralized bone-to-implant-contact of 27.1%, the DFDBA+GTAM group of 34.6%, and the HA+GTAM of 39.3%. The mineralized bone-to-implant-contact of the HA+GTAM group was significantly higher than that of the GTAM alone group. In addition, the mineralized bone-to-implant-contact was divided into an apical and coronal part using the apical seventh thread as the dividing landmark. In the apical region, there was no significant difference between the groups regarding mineralized bone-to-implant-contact. In the coronal part the mineralized bone-to-implant-contact of the GTAM alone group was significantly lower compared to the other 2 groups. Within the limits of this investigation, it can be concluded that the type of grafting material will not influence torque removal values, but that early membrane exposure and removal will negatively influence the torque measurements. The combination of GBR with a bone substitute increased the mineralized bone-to-implant contact.

Effect of social deprivation on disease severity and outcome in patients with rheumatoid arthritis

OBJECTIVE

Social deprivation is now recognised to have an important impact on morbidity and mortality. This study sought to ascertain the effect of deprivation, if any, on disease severity, functional disability, and outcome in rheumatoid patients in Glasgow.

METHODS

814 patients with rheumatoid arthritis (RA) were assessed for clinical, functional, and laboratory indices of disease activity. Deprivation categories for individual patients were determined using the Carstairs index. Five year follow up is available for 440 patients.

RESULTS

The study population of RA patients live largely in the most deprived areas. Patients from deprived areas have significantly poorer function at outset and at five years as defined by the Health Assessment Questionnaire (HAQ) score. This is not attributable to differences in disease duration in patients from the most deprived regions or compliance with treatment. Furthermore, these patients do not achieve over five years the initial functional level of those living in the most advantaged localities.

CONCLUSION

RA patients from deprived areas have poorer function, which is associated with greater need--medical, social, and paramedical. Strategies and resources for healthcare need to be adjusted according to this variation.

Activated mesothelial cells produce heparin-binding growth factors: implications for tumour metastases

Curative surgery for gastrointestinal malignancy is commonly thwarted by local tumour recurrence. The heparin-binding growth factors, basic fibroblast growth factor (bFGF), heparin-binding epidermal growth factor-like growth factor (HB-EGF) and vascular epidermal growth factor (VEGF) are all implicated in the metastatic process, but whether or not these essential growth factors are produced by the activated peritoneum is unknown. This study reveals that peritoneal mesothelial cells constitutively express mRNA for bFGF, HB-EGF and two VEGF spliced variants, VEGF121 and VEGF165. Mesothelial activation with interleukin (IL)-1b or tumour necrosis factor (TNF)-a produced an up-regulation of mRNA for HB-EGF and VEGF, but not bFGF expression. IL-6 failed to stimulate growth factor expression, whereas IL-2 produced a marked suppression in HB-EGF and bFGF, but not VEGF expression. Mesothelial cells were shown to predominantly express mRNA for the intermediate affinity (bg(c)) IL-2 receptor. Cytokine-induced growth factor up-regulation was confirmed at the protein level using Western blotting of mesothelial cell lysates for HB-EGF and culture supernatant enzyme-linked immunosorbent assay for VEGF. The production of these growth factors by human mesothelial cells may play a significant role in post-operative peritoneal tumour recurrence. Their common heparin-binding property offers a potential therapeutic target for manipulating the growth factor environment of the human peritoneum.

Attitude of rheumatoid arthritis patients to treatment with oral corticosteroids

OBJECTIVE

To assess the attitudes of rheumatoid arthritis (RA) patients to oral corticosteroid treatment, factors influencing these views and their likely clinical impact.

METHODS

A cross-sectional survey of 158 consecutive RA out-patients was carried out at two centres over 2 weeks. Demography, disease duration, function [Health Assessment Questionnaire (HAQ)], erythrocyte sedimentation rate (ESR), years of formal education and social deprivation index were noted. Prospective recruitment into the multicentre West of Scotland Early Rheumatoid Arthritis Corticosteroid Trial (WOSERACT) was monitored and reasons for refusal to participate (when available) were noted at three of the centres.

RESULTS

Forty-eight (32%) patients were willing to be treated with oral corticosteroid and 100 (68%) were not. The former were older (P = 0.002), had a higher ESR (P = 0.007), poorer function (P = 0.001) and greater previous exposure to disease-modifying anti-rheumatic drugs (P = 0.013). Ninety patients refused to participate in WOSERACT, in 46 cases (40 female, 6 male) the reason being concerns about corticosteroids.

CONCLUSIONS

This study shows a high level of concern about and refusal of corticosteroid treatment in RA, due mainly to patient concerns about adverse effects. Rheumatologists need to be aware of these attitudes as they are likely to affect prescribing.

Mechanisms involved in the induction of apoptosis by T-2 and HT-2 toxins in HL-60 human promyelocytic leukemia cells

T-2 and HT-2 toxins belong to a group of mycotoxins that are widely encountered as natural contaminants known to elicit toxic responses in hematopoietic cells. In the present study, HL-60 cells were used to characterize the apoptotic effects of T-2 and a major metabolite, HT-2, and to examine the mechanisms involved. Apoptotic cells were identified microscopically by chromatin condensation and nuclear fragmentation, by flow cytometric analysis, and by DNA gel electrophoresis. T-2 and HT-2 induced concentration-dependent apoptosis after 24 h in HL-60 cells, starting at concentrations of 3.1 and 6.25 ng/ml respectively. An increased number of apoptotic cells could be observed 4-6 h after exposure to 12.5 ng/ml of toxin. Little cytotoxicity (plasma membrane damage) was observed even after exposure to concentrations of toxins (25-50 ng/ml) inducing apoptosis in 60-100% of the cells. The apoptotic process was almost completely blocked in the presence of the general caspase inhibitor zVAD.fmk. In contrast, no or only minor effects were observed with the more specific caspase inhibitors DEVD.CHO, IETD.fmk, and DEVD.fmk. As judged by Western blotting, the levels of several procaspases (-3, -7, -8, -9, but not -12) were reduced 3-6 h after exposure to toxin. Substantial increases in the presumed active form(s) of caspase-8 and -9 were observed. Furthermore, poly(ADP-ribose) polymerase (PARP) was already markedly cleaved 3 h after toxin treatment, indicative of active caspase-3 and -7. No or only minor changes in Bcl-2, Bcl-XL and Bax levels were observed. BAPTA-AM and ZnCl2 blocked the degradation of procaspases, the fragmentation of PARP, and the induction of apoptosis. In summary, both T-2 and HT-2 induced apoptosis, with T-2 being somewhat more potent than HT-2. The divalent calcium concentration, [Ca2+], appears to be involved in the activation of several caspases, resulting in DNA fragmentation, chromosomal condensation, and nuclear fragmentation.

Assessment of guided tissue regeneration procedures in intrabony defects with bioabsorbable and non-resorbable barriers

THE PURPOSE OF THIS STUDY was to assess periodontal regenerative techniques in intrabony defects utilizing a bioabsorbable, polylactic acid (PLA) barrier or the non-resorbable, expanded polytetrafluoroethylene (ePTFE) barrier. Thirty patients (26 to 64 years old) each with one radiographically evident intrabony periodontal lesion of probing depth > or = 6 mm participated in a 12-month controlled clinical trial. The subjects were randomly divided into two independent groups. The test group (n = 16) received a PLA barrier. The control group (n = 14) received an ePTFE barrier. Plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL), and bone fill were recorded by a single calibrated examiner not involved with the surgical treatment prior to surgery, and at 6, 9, and 12 months postsurgery. The treatment results were statistically analyzed utilizing two sets of data. The "averaged-site" data set consisted of values computed from the averaging of measurements from all sites encompassing the defect. The second data set was comprised of only the deepest measurement of the defect. Statistical tests used to analyze these data sets included the t-test and paired t-test for parametric data and the Wilcoxon rank sum test and the Wilcoxon signed rank test for non-parametric data. Analyses with both the averaged-site data and deepest-site data resulted in significant improvements in PD reductions, CAL, and bone fill, after 12 months of healing with both the PLA and ePTFE barrier devices. Comparisons of healing response between treatments found no significant differences when the averaged-site data were analyzed. When only the deepest site of the defect was considered, the control group resulted in significantly more attachment gain (ePTFE, 3.36 mm; PLA, 1.75 mm; P < 0.02) and shallower probing depths (ePTFE, 3.29 mm; PLA, 4.69 mm; P < 0.01) than the test group. In intrabony defects, the use of PLA or ePTFE barriers in GTR procedures yielded comparable clinical results; however, in this study, data analysis using the deepest site of the defect found, after 12 months of healing, significantly more attachment gain and shallower probing depths with ePTFE.

Acute meningoencephalitis after withdrawal of antibiotics in Whipple's disease

A man with Whipple's disease was treated with oral penicillin (500 mg twice a day) for 2 years with eradication of bacillary organisms from the jejunum and a return of jejunal histologic findings to normal. While he was on this regimen, however, intermittent vertigo and tinnitus and decreased auditory acuity developed. Two days after penicillin was withdrawn, the patient developed acute meningoencephalitis that responded to parenteral penicillin and chloramphenicol therapy. Subsequently, central nervous system signs and symptoms and cerebrospinal fluid pleocytosis have been controlled with chronic chloramphenicol therapy. Penicillin may suppress, but not prevent, central nervous system disease in patients with otherwise successfully treated Whipple's disease.

The effects of explicit timing and feedback on compositional response rate in elementary school children

The effects of several variables on compositional response rate were investigated in three classrooms. After establishing baseline composition rates in each of the three classrooms, an experimental phase was introduced that consisted of: explicit timing of the children's composition period with a stopwatch, immediate feedback on the number of words each child produced, public posting of the greatest number of words written by each child to date, and instructions to try to exceed their highest score. In the second-grade classroom, these conditions were introduced, removed, and re-introduced. In two fifth-grade classrooms, these conditions were introduced according to a multiple baseline, across classes. In all cases, introduction of the experimental conditions led to a doubling of rate of words written by students and an increase in subjective quality ratings of compositions made by independent judges.

Effects of the situational context and interactional process on the quality of family caregiving

A staged theoretical model designed to explain the quality of elder caring by family members was tested. The model posits how the situational context, interactional process, and caregiving burden perceived by the caregiver affect the quality of elder caring. The purpose was to determine the amount of variance explained by the interactional process beyond that explained by the situational context and caregiving burden. Data were collected from 209 elder-caregiver dyads using interviews, observations, and caregiver self-reports. The strongest predictors of caregiving burden were the caregiver's stressful negative life events (situational context) and discrepancy between past and present image of elder (interactional process). The strongest predictors of quality of elder caring were the caregiver's perception of subjective burden and a monitoring role definition on the part of the caregiver (interactional process).