Epithelial expression of major histocompatibility complex (MHC) antigens in normal rat salivary and lacrimal glands.

The presence and distribution of MHC class I and class II antigens within these glands of Wistar and Lewis rats was studied using monoclonal antibodies and an indirect immunoperoxidase technique. In rats of both strains and sexes, MHC class 1 antigens were expressed by ductal epithelium in addition to vascular endothelium and other connective tissue elements. Except for a small proportion of secretory cells within lacrimal glands, acini were uniformly negative for class I antigen. MHC class II immune response-associated (Ia) antigens were expressed by stromal dendritic cells in all glands. Glandular expression of Ia was limited to submandibular glands of the two strains. In Lewis rats, staining was detected in some striated and collecting ducts, whereas positive glandular reactivity in Wistar rats was predominantly within the granular-cell tubules. Quantitative histomorphometric studies of Wistar submandibular glands, taken from 2.5-60-week-old male and female animals, demonstrated a close relationship between the extent of glandular Ia reactivity and postnatal granular-cell tubule development. These results indicate that whilst constitutive expression of Ia is a feature of rat submandibular epithelium, the glandular components involved are strain dependent.     

Nifedipine-induced gingival hyperplasia.

Gingival hyperplasia is an adverse reaction of nifedipine therapy. Oral manifestations of this condition include enlarged and painful gingiva accompanied by spontaneous bleeding. Nifedipine-induced gingival hyperplasia may be reversible once a proper drug substitution is made. Two cases of gingival hyperplasia resulting from nifedipine are described and the drug's possible mode of action is discussed.     

Responses of calcitonin gene-related peptide-immunopositive nerve fibres in the periodontal ligament of rat molars to experimental tooth movement.

Nerve fibres showing CGRP-immunoreactivity were exclusively distributed around blood vessels in the periodontal ligament of normal teeth. The CGRP-positive nerves as well as the vessels were more dense during tooth movement and reached a maximum density and intensity of immunoreaction after 3 days. After that, the immunoreactive nerves gradually disappeared, and returned to the control level by the 7th day. Some of the CGRP-nerves were adjacent to bone resorptive lacunae at 3 days when active remodelling of alveolar bone was taking place. These findings suggest that the distribution of CGRP-positive nerves is dynamically changed around the blood vessels in the periodontal ligament during tooth movement, and that CGRP might affect the regulation of blood flow in the ligament. CGRP is possibly involved in the tissue remodelling, directly or indirectly, in addition to its function as a neurotransmitter.     

Effect of phenytoin and nifedipine on collagen gene expression in human gingival fibroblasts

Phenytoin (PHT), a widely used anticonvulsant, and nifedipine (NF), an anti-anginal drug, cause clinically similar gingival overgrowths in some patients. The aim of this work was to investigate their effects on collagen and protein synthesis and cellular proliferation in normal human gingival fibroblasts in vitro. Gingival fibroblasts were cultured from biopsies taken from three healthy individuals during operations on maxillary canines and incubated with various concentrations of NF (100 and 200 ng/ml) and PHT (5 and 10 micrograms/ml) for up to 7 days. The results showed that NF and PHT have a specific effect in reducing total protein and collagen synthesis but do not influence cell proliferation in healthy gingival fibroblasts in vitro. In addition the level of mRNA for type I collagen was decreased after incubation of the cells with the drugs for 1 or 2 days. The decrease in the level of type I collagen mRNA seemed to be specific since the level of type IV collagenase mRNA used as a reference RNA did not decrease.     

CT diagnosis of synovial chondromatosis of the temporomandibular joint

Synovial chondromatosis of the temporomandibular joint (TMJ) is a very rare condition. It is characterised by the presence of loose bodies in the joint space. Clinical signs, histopathological findings and radiography play an important role in the diagnostic process. Conventional X-rays have shown to be of limited value, for they fail to depict the intra-articular loose bodies in a significant amount of cases. Axial as well as coronal computer tomography (CT) is extremely useful in detecting loose bodies in the temporomandibular joint (TMJ). In this report we present and discuss a further case, and the use of CT in the diagnosis of TMJ-synovial chondromatosis is illustrated.     

Longevity of posterior restorations

The efficacy of restorative dentistry is dependent on a number of factors, including material quality, operator proficiency and the oral hygiene of the patient. The sum effect of all factors can be measured by recording the longevity of the restorations. Many studies focus on the age of restorations at the time of failure, others include the longevity of restorations which remain in situ. The surveys may be either longitudinal, prospective or retrospective, or cross-sectional retrospective studies of dental records. They are all hampered by the lack of uniform criteria defining when to place and replace restorations and by variations in decision-making between clinicians. The present review paper shows that the longevity of amalgam restorations has been studied most frequently. About 50 per cent of all amalgam restorations exceed 8-10 years in age, cast gold restorations may last longer and multisurfaced composite restorations have a shorter life-span. Glass ionomer cements lack the physical properties needed for large posterior restorations. The results of detailed longevity studies should be the basis for selection of materials and techniques in operative/conservative treatment. The cost of dental treatment should be related to the expected lifetime of the tooth rather than to the immediate cost of a simple restoration.     

Clinical significance of serum acid soluble glycoproteins (ASP) and immunosuppressive acidic protein (IAP) in inflammatory diseases and liver diseases

In order to study the clinical significance of ASP and IAP, we have measured serum concentration of ASP and IAP in 259 patients with inflammatory diseases, non-inflammatory diseases, autoimmune diseases and liver diseases. Significantly higher correlation (coefficient of correlation = 0.922) was found between ASP and IAP. There were good correlation between ASP, IAP levels and erythrocyte sedimentation rate (ESR), C-reactive protein (CRP). Coefficient of correlation were 0.705 and 0.673 between ESR and ASP, IAP; 0.621 and 0.623 between CRP and ASP,IAP, respectively. There were food correlations between ASP levels and thrombo test (TT) and hepaplastin test (HPT). The positive rate and mean concentration of ASP, IAP in patients with inflammatory diseases were significantly higher than noninflammatory diseases. It is suggested that serum ASP, IAP could be one of the useful indicator for evaluating the clinical course of patients with inflammatory diseases. Serum concentration of ASP, IAP in patients with chronic liver diseases were lower than normal subjects, especially serum levels in patients with decompensated liver cirrhosis and chronic hepatitis (active) were significantly lower than normal subjects. In patients with hepatoma with cirrhosis, serum levels of ASP, IAP were significantly lower than the hepatoma patients without cirrhosis. The determination of ASP, IAP in liver diseases seems to be useful for evaluating the severity of diseases, the effects of therapy and the forecast of prognosis.     

Clinical evaluation of serum immunosuppressive acidic protein (IAP) and acid soluble glycoproteins (ASP) in patients with malignant tumors

In order to study the clinical significance of IAP and ASP, we have measured serum concentration of IAP and ASP in patients with different cancer types including digestive organs, head and neck. Significantly higher correlation (coefficient of correlation = 0.924) was found between IAP and ASP. IAP and ASP levels were elevated in about 60-80% of cancer from digestive organs except hepatocellular carcinoma, and in about 56-100% of head and neck tumor. There was no correlation between IAP, ASP and various tumor markers (CEA, CA19-9, AFP) in all malignancies except pancreatic cancer. There was positive correlation between CEA and IAP, ASP in pancreatic cancer. IAP and ASP levels were significantly higher in patients with cancer having evidence of disease than the patients with cancer who had no evidence of disease, and so the determination of IAP and ASP was clinically useful for the diagnosis of tumor existence. At the time of diagnosis of recurrence, the levels of IAP and ASP were elevated in about 70% of patients with cancer recurrence. There was a definite relation between IAP, ASP and the gastric cancer stage. In later state (stage III and IV), serum IAP and ASP levels were significantly higher than the levels of stage I and II. In hepatocellular carcinoma without liver cirrhosis, the levels of IAP and ASP were higher than the patients with cirrhosis. The determination of IAP and ASP seems to be useful for monitoring clinical course, judgement of therapeutic effects.     

Anterior-inferior mandibular osteotomy in treatment of obstructive sleep apnea syndrome

In a prospective randomized study on treatment of obstructive sleep apnea syndrome, anterior-inferior mandibular osteotomy with the purpose of stretching the suprahyoidal muscle was performed as one of the treatment methods. Ten men aged 20 to 65 years, without cardiovascular or neurologic disease, with normal maxillomandibular relation, and having an apnea index between 5 and 25 were included in the study. After a specially designed osteotomy of the chin, the anterior suprahyoidal muscles were detached, stretched approximately 10 to 12 mm, and sutured. The chin was then placed in its original position and post-operative evaluation was performed. Although there were initial reports of decreased daytime sleepiness and less snoring after surgery, the results after 12 months were discouraging. Somnographic registration (apnea index, apnea/hypopnea index, and oxygen desaturation index) as well as cephalometric analysis failed to show positive results. Hence, suspension of the suprahyoidal muscles as a method of treatment for obstructive sleep apnea syndrome cannot be recommended.