Inhibition of cytochrome P-450 3A (CYP3A) in human intestinal and liver microsomes: comparison of Ki values and impact of CYP3A5 expression

Seckel syndrome has been described as the prototype of the primordial bird-headed type of dwarfism. Since Seckel originally defined the disorder, less than 60 cases have been reported. In addition to the characteristic craniofacial dysmorphism and skeletal defects, abnormalities have been described in the cardiovascular, hematopoietic, endocrine, and central nervous systems. This pleiotropy has implied genetic heterogeneity and prompted reviews of previously reported cases of Seckel syndrome. As a result, the characteristic diagnostic features of Seckel syndrome have been highly debated. Although deletions in chromosome 2q have been described, to date, no genetic defect has been defined. We report three cases of Seckel-like syndrome in siblings from nonconsanguinous Caucasian parents. In addition to the typical Seckel phenotypic features, all three cases were characterized by severe hydrocephalus. We review the literature and propose that there is a spectrum of Seckel conditions that share some common key features, but also demonstrate a wide range of phenotypic features.     

Co-ordinated expression of connexins 26 and 32 in human endometrial glandular epithelium during the reproductive cycle and the influence of hormone replacement therapy

A boy presented at 5 weeks with a syndrome of pre- and postnatal growth retardation, microcephaly, muscular hypotonia, and facial anomalies resembling those seen in Seckel syndrome or microcephalic primordial dwarfism I. Analysis of prometaphase chromosomes, fluorescent in situ hybridization (FISH), and molecular studies showed the presence of a de novo chromosome 2 deletion that could be defined as del(2)(q33.3q34)pat. Parental chromosomes were normal, except for the presence of a paternal supernumerary marker identified by FISH as der(15). On follow-up of the patient during the next months length development appeared normal and the diagnosis of Seckel syndrome was withdrawn. Clinical findings of previously published cases with interstitial deletion of at least 2q33.3-q34, the deletion present in the propositus, are reviewed and include pre- and postnatal growth retardation, psychomotor retardation, microcephaly, micrognathia, and abnormal/low-set ears; findings also present in the propositus. These findings resemble those described in the Seckel syndrome. Noteworthy is the finding that 2/3 of the 60 reviewed cases originally reported as having Seckel syndrome apparently belong to a heterogeneous group of low birth weight microcephalic dwarfism I yet to be clearly defined. In these patients no chromosome 2q deletion has been reported so far. Retrospective analysis could show if a subgroup of these patients carry submicroscopic deletions at 2q33.3-q34. Alternatively, molecular analysis of this region may be warranted in newly diagnosed patients with Seckel syndrome-like manifestations.     

Plasticity of the visual system and learning]

Seckel syndrome is a clinical picture which associates four main features: intrauterine growth retardation, microcephaly often due to craniosynostosis, orofacial dysmorphology with bird headed appearance and variable mental retardation which is present after several months. Malformations of the central nervous system, limbs, and hair, may also be observed. On the basis of 78 cases reported in the literature, the authors discuss the validity of the morphological features of the syndrome. It is likely that the variability in the expressivity of each symptom explains its heterogeneity. According to the radiological abnormalities, three different forms of the syndrome have been described. Seckel syndrome is a genetic disorder with autosomal recessive inheritance. Its ethiopatogeny remains unclear. Hopefully linkage studies will allow to map the gene in order to determine the underlying abnormal protein.     

Anesthetic management of Seckel syndrome: a case report

Seckel syndrome is a rare syndrome of chromosome aberration, in which bird-headed dwarfism, microcephalus and other minor deformities are recognized. A 24-year-old male patient with Seckel syndrome underwent both abdominal and orthopaedic surgeries in 1 year under general anesthesia. The first operation was an emergent operation under preshock state and enterostomy was performed. The second was arthrodesis of the hip joint. Before the second operation, laryngeal CT, tomography and fiberscopy revealed stenosis just below his vocal cord. During the second operation, the anesthesia was unsatisfactory with inhalation of nitrous oxide and sevoflurane and intravenous vecuronium, because of intraoperative abnormal hypertension. But the recovery from the anesthesia was prompt. Although we experienced no difficulty in intubation except for intraoperative abnormal hypertension, preoperative laryngeal and renal examinations are necessary in the anesthetic management of this syndrome.     

Complications associated with diabetes mellitus after guided tissue regeneration: case report

Dental practitioners need to be aware of the complications that can arise in the management and treatment of patients with diabetes mellitus. Patients with diabetes, and patients with a family history of diabetes, are at-risk dental patients. They are more likely to develop periodontal disease, and the periodontitis is more likely to be severe. Diabetes influences the progression and severity of periodontitis through changes in the small blood vessels, decreased collagen formation, and impairment of the host's defense mechanisms. Furthermore, complications associated with diabetes, such as impaired wound healing, can affect the patient's response to periodontal therapies like guided tissue regeneration (GTR). The case report in this article discusses the postsurgical complications that occurred during GTR treatment of a patient with non-insulin-dependent diabetes. The diabetic's susceptibility to periodontal disease and impaired wound healing can affect the progression of the disease and its treatment. Dental patients with diabetes require close supervision and frequent monitoring of their medical and dental health by the dental clinician.     

Dental findings in an adult with Lowe's syndrome

This paper describes the dental findings and care of a Chinese adult affected with oculo-cerebro-renal syndrome--Lowe's syndrome--a rare, X-linked recessive disorder, whose clinical manifestations include cataracts, mental retardation, and renal tubular dysfunction. Approximately 150 cases have been reported in the last 45 years. Little has been reported in the dental literature. This patient is described with particular reference to the dental findings, which include gross periodontal disease with severe bone loss, impaction of teeth in the permanent dentition, taurodontism, and underdevelopment of the maxilla and mandible. Dental treatment was aimed at arresting the periodontal disease and preserving the remaining dentition.     

Dental disease, fibrinogen and white cell count; links with myocardial infarction?

Plasma fibrinogen and white blood cell count were compared in fifty patients aged 25-50 years with periodontal disease and in fifty age-matched controls with relatively healthy periodontal tissues. Patients had significantly higher levels of fibrinogen and white cell count, and dental indices correlated significantly with these two cardiovascular risk factors on multivariate analyses. We suggest that inflammatory dental disease may be a determinant of fibrinogen level and white cell count in the general population, and that fibrinogen and white cell count may be two mediators of the link between dental disease and myocardial infarction.     

The changes of PRA, ATII, ald, ET and ANP in patients with left ventricular diastolic heart failure and intervention with enalapril

Several syndromes and aneuploidies are associated with ocular abnormalities including up- and down-slanting palpebral fissures. We describes a technique for the sonographic assessment of the fetal palpebral fissure slant which was used in 70 normal pregnancies from 14 to 36 weeks of gestation. In a frontal view of the fetal face, the inferior angle between the palpebral fissure and the midline of the skull was determined. The median angle was 89 degrees, with a range from 87 degrees to 90 degrees. In selected cases, sonographic assessment of the fetal palpebral fissure slant may be a helpful additional tool in the prenatal diagnosis of syndromes, as demonstrated in a fetus with Seckel syndrome associated with downslanting palpebral fissures and in a fetus with Down's syndrome associated with upslanting palpebral fissures.     

The influence of alveolar structures on the torsional strain field in a gorilla corporeal cross-section

Anthropologists have often used mandibular torsional properties to make inferences about primate dietary adaptations. Most of the methods employed are based on assumptions related to periodontal and alveolar properties. This study uses the finite element method to evaluate some of these assumptions with a cross-section through the third molar of a gorilla. Results indicate that the properties of alveolar bone play an important role in determining the strain field. In comparison, the exact stiffness values of the periodontal ligaments seem to have a much smaller impact. Replacing the dental roots and periodontal ligaments with alveolar bone, however, has a significant influence on the strain field. It underestimates the maximum shear strain by about 28% along its periosteal aspect when alveoli are modeled as cortical bone. It overestimates the strain by a smaller amount when alveoli are modeled as trabecular bone. This study supports the assumption that primate mandibles behave like a closed-section under torsion under the limiting condition that the alveolar bone stiffness is more than half of the value of cortical bone; alveolar bone can then be modeled as cortical bone with a minimal loss of accuracy. In addition, this study suggests that the minimum cortical thickness should be considered for torsional strength. Finally, modeling accuracy can be significantly increased if both dental and periodontal structures can be realistically incorporated into mandibular biomechanical models. However, this may not be always feasible in studies of fossil mandibles. This is due mainly to the difficulties involved in estimating alveolar bone densities and in distinguishing boundaries between cortical bone, alveolar bone, periodontal ligaments, and dental roots in fossil specimens.     

School policy in COMMIT: a promising strategy to reduce smoking by youth

Destructive periodontal disease is found in a significant number of adult patients. At present there is no reliable method of determining the presence of active periodontal disease, other than retrospectively. Tests are being developed that rely on various markers of periodontal disease activity but all of those produced to date have limitations. It is to be hoped that reliable tests that can be used at the chairside will help the general dental practitioner to combat periodontal disease before it progresses too far.     

Periodontal and dental considerations in clinical crown extension: a rational basis for treatment

When the clinical crowns of teeth are dimensionally inadequate, esthetically and biologically acceptable restoration of these dental units is difficult. Often an acceptable restoration cannot be accomplished without first surgically increasing the length of the existing clinical crowns; therefore, successful management requires an understanding of both the dental and periodontal parameters of treatment. This report provides further insight into this interdependence by examining the effects of tooth form on the periodontal morphology and surgical treatment, while relating them to requirements for esthetically and biologically acceptable full-coverage dental restorations. This report also explains the role that restoration margin location and emergence profile play in the maintenance of periodontal and dental symbiosis. The effects of violation of the supracrestal gingivae by improper full-coverage restorations is also illustrated.     

Ischemia detection in women: the diagnostic value of exercise QRS duration changes

The purpose of this review article is to provide the dental practitioner with an understanding of the interrelationship between periodontics and orthodontics in adults. Specific areas reviewed are how periodontal tissue reacts to orthodontic forces, influence of tooth movement on the periodontium, effect of circumferential supracrestal fiberotomy in preventing orthodontic relapse, effect of orthodontic bands on the periodontium, specific microbiology associated with orthodontic bands, mucogingival considerations and time relationship between orthodontic and periodontal therapy. In addition, the relationship between orthodontics and implant restorations (e.g., using dental implants as orthodontic anchorage) will be discussed.     

A comparison of moderate and high users of Alberta's universal dental plan for the elderly

The characteristics and service utilization of 2,071 high and 2,337 moderate users of Alberta's dental plan from 1978-79 to 1990-91 are reported. High users are those who used the plan for 14 consecutive years; moderate users are those who used the plan in seven of the 14 years. Both groups were over 74 years of age in 1991-92. Compared to high users, moderate users lived in less urbanized regions, visited denturists more often and received far more complete dentures and fewer partial dentures. As a percentage of their total annual plan expenditures, moderate users spent less on diagnostic, preventive, periodontal and restorative services and much more on removable prosthodontic and denturists' services. However, during the study period, the moderate users increased their annual relative expenditures for diagnostic, preventive and, especially, periodontal services, and decreased them for prosthodontic services. With respect to specific preventive and periodontal services, the percentage of total annual expenditures for dental prophylaxis, topical fluoride applications, periodontal scaling, gingival curettage, and combinations of these, was much higher for the high user group. Despite these differences favoring the high user group, during the 14 year period, the moderate user group considerably increased its relative expenditures for dental prophylaxis, topical fluoride and periodontal scaling services. While the observed differences in service expenditures between high and moderate users were anticipated, the shift over time to using more preventive and periodontal services by both groups was an encouraging harbinger of the "new elderly" dental patients.     

The oral status in mentally retarded institutionalized patients

BACKGROUND AND METHODS: An epidemiological survey of dental and periodontal health status was conducted in a group of 263 institutionalized mentally retarded patients. RESULTS: The periodontal status in the study population was very poor. 66% of the subjects presented with a probing depth more than 3.5 mm (PSR = 3 or 4), 29% showed the presence of bleeding or calculus (PSR = 1 or 2) and only 5% showed a normal periodontal status (PSR = 0). No statistical relationship was found between periodontal status and age, sex, type or duration of psychiatric therapy. Concerning the dental status a total of 59 (26%) subjects was totally edentulous. A significant increase in the prevalence of edentulousness with increasing age was recorded. The incidence of edentulousness was higher among women than among men, while it was not significantly influenced by the type of psychiatric pathology, type or duration of psychiatric therapy. The mean number of remaining teeth in every subject was 12.9 +/- 9; the mean number of sound teeth was 10.8 +/- 8 and the mean number of decayed teeth was 2.1 +/- 3. The number of decayed teeth decreased with increasing age and it was influenced by the type of psychiatric pathology, but not by the type or duration of psychiatric pathology. CONCLUSIONS: Analysis of the results showed a very poor dental but especially periodontal status in mentally retarded subjects as compared to those found in studies performed in normal subjects.     

Influences of smoking on the periodontium and dental implants

The purpose of this article is to review current information on the role of smoking in destructive periodontal disease and in increasing the likelihood of failure of endosseous dental implants. Practical recommendations are made on the role of the dental health professional in everyday dealings with patients who smoke.     

Periodontal complications of HIV infection

As the scope of the acquired immunodeficiency syndrome (AIDS) epidemic grows to include increasingly larger proportions of heterosexual adults and children, there has also been a change in the severity of human immunodeficiency virus (HIV)-related periodontal conditions at one San Francisco clinic. The cases of HIV-associated gingivitis, now called linear gingival erythema, HIV-associated periodontitis (or necrotizing ulcerative periodontitis), and necrotizing stomatitis have been less severe, despite an increase in overall HIV caseload. No clear basis for this trend has been established, but possible explanations include: biased population samples, increased immunosuppression as the disease matures, use of antimicrobial therapy, or a change in patient demographics. Several studies have failed to identify a single causative organism. This article presents a review of HIV-related periodontal complications and points out that the condition can be treated with local and systemic antibiotics and that dental professionals throughout the world can expect a tremendous increase over the next several years in HIV-infected patients with special clinical complications.     

Dental dysplasia in rats and mice

Malformations of the maxillary incisors, diagnosed as dental dysplasia, were observed as a spontaneous background lesion in 3% (females) to 9% (males) of CD-1 mice and 14.5% (females) to 10.5% (males) of CD (Sprague-Dawley) rats in a chronic inhalation study. Lesions were reported grossly as overgrown, maloccluded, or malformed incisors. Microscopic findings included tooth pulp and periodontal abscesses, fractured and necrotic teeth, periodontal cysts, malformations of the incisor roots, and expansile masses, including odontomas, of the incisor roots. Development of lesions followed a pattern of tooth pulp necrosis and/or traumatic disruption of the epithelial root sheath at the base of the tooth. Feeding a powdered ration, which reduced the normal wearing of the incisors, and repeated clipping of overgrown incisors were believed to contribute to the incidence of disease.     

The detection of abnormal bleeding

The aim of this study was to analyse the distribution of the stress on dental and periodontal structures when a simple tipping dental movement or torque movement is produced. A tridimensional computer model based on finite element techniques was used for this purpose. The model of the lower canine was constructed on the average anatomical morphology and 396 isoparametric elements were considered. The three principal stresses (maximum, minimum and intermediate) and Von Mises stress were determined at the root, alveolar bone and periodontal ligament (PDL). It was observed how the distribution of stress is not the same for the three structures studied. In all loading cases for bucco-lingually directed forces, the three principal stresses were very similar in the PDL. The dental apex and bony alveolar crest zones are the areas that suffer the greatest stress when these kind of movements are produced.     

Clinical parameters associated with periodontitis in untreated persons

The purpose of this study was to investigate the relationship between clinical parameters and periodontitis in a population receiving no regular prophylactic dental care. From a sample of 164 adult rural and urban Tanzanian subjects aged between 30 and 44 years, 16% were identified with periodontitis according to the criteria that at least three teeth had a probing depth > or = 6 mm. Subjects with periodontitis in this sample exhibited a much higher bleeding tendency (at sites where periodontal pockets and did not exist) than subjects without periodontitis, but dental plaque scores were comparable. Sensitivity and specificity values and odds ratios indicated a strong association between bleeding on probing and the presence of periodontitis. This may indicate that people from a population deprived of regular dental care with a high tendency of bleeding on probing are more prone to develop periodontitis. Whether bleeding on probing could serve as a marker in this population to identify subjects who develop future periodontal destruction has to be explored through further longitudinal studies.     

Empyema due to Streptococcus mutans

Empyema due to Streptococcus mutans occurred following dental manipulation in two patients with periodontal disease. Isolation of this dental pathogen from pleural fluid localized the site of origin of the empyemas to the oropharynx and precluded the need to search for a remote intra-abdominal source of these pleuropulmonary infections. Although there is controversy regarding the susceptibility of S mutans to penicillin, the isolates from our patients were markedly sensitive to the drug, and both patients were cured with penicillin therapy and surgical drainage.