Reduced expression of dipeptidyl peptidase (DPP) IV in peripheral blood T lymphocytes of oral cancer patients

To investigate the mechanism of decrease of serum DPP IV activity in oral cancer patients, we analyzed the expression of DPP IV in peripheral blood T lymphocytes of oral cancer patients and healthy subjects. Consequently, serum DPP IV activity was found to correlate significantly with the number of peripheral blood lymphocytes (PBL), T lymphocytes and CD26 (identified as DPP IV)+ T lymphocytes in healthy subjects, and the number of PBL and CD26+ T lymphocytes in cancer patients. However, the numbers of PBL and T lymphocytes were significantly less in cancer patients than in healthy subjects. Although the number of CD26+ T lymphocytes was somewhat greater in cancer patients than in healthy subjects, serum DPP IV activity was significantly lower in cancer patients. DPP IV activity and amount of CD26 in T lymphocyte plasma membranes were much less in cancer patients than in healthy subjects. These findings suggest that a decrease in the number of T lymphocytes and the small amount of DPP IV in their plasma membrane may contribute to the decrease of serum DPP IV activity in cancer patients.

Fatty acids selectively inhibit eukaryotic DNA polymerase activities in vitro

The in vitro relationship between eukaryotic DNA polymerases and fatty acids was investigated. Some fatty acids strongly inhibited the activities of DNA polymerase alpha and/or beta in vitro. The kinetics of inhibition by linoleic acid showed that DNA polymerase alpha was non-competitively inhibited with respect to the DNA template and substrate (dTTP), while DNA polymerase beta was inhibited competitively with both DNA and substrate.

Non-T cell-derived IL-4 plays an important role in IgE production induced by antigen resensitization and is resistant to FK506

The present study investigates the role of non-T cell-derived IL-4 in IgE production. It is well known that IL-4 is generally produced by T cells and induces IgE production. We have demonstrated that non-T cells also produce IL-4 in vivo by injection with Ag following passive sensitization of mice with IgE. In contrast to its known potent immunosuppressive effects on T cells, FK506 only partially inhibited IL-4 produced by non-T cells; therefore, FK506 was found to be a useful tool for identifying a cell source of IL-4 production. We used this observation to examine the role of non-T cell-derived IL-4 in IgE production. The production of a high titer of IgE was induced by priming BALB/c mice with Ascaris suum extract and further enhanced by secondary immunization. The IgE production in this model was dependent on IL-4, since both primary and secondary IgE production were completely suppressed by injection with anti-IL-4 Ab. Although primary IgE production was completely inhibited by FK506, secondary IgE production was not inhibited. Furthermore, IL-4 induction in plasma was only partially inhibited by FK506 when the A. suum extract-primed mice were resensitized with Ag. These results indicate that IL-4 produced by non-T cells plays a crucial role in secondary IgE production.

Non-T cell-derived IL-4 plays an important role in IgE production induced by antigen resensitization and is resistant to FK506

The present study investigates the role of non-T cell-derived IL-4 in IgE production. It is well known that IL-4 is generally produced by T cells and induces IgE production. We have demonstrated that non-T cells also produce IL-4 in vivo by injection with Ag following passive sensitization of mice with IgE. In contrast to its known potent immunosuppressive effects on T cells, FK506 only partially inhibited IL-4 produced by non-T cells; therefore, FK506 was found to be a useful tool for identifying a cell source of IL-4 production. We used this observation to examine the role of non-T cell-derived IL-4 in IgE production. The production of a high titer of IgE was induced by priming BALB/c mice with Ascaris suum extract and further enhanced by secondary immunization. The IgE production in this model was dependent on IL-4, since both primary and secondary IgE production were completely suppressed by injection with anti-IL-4 Ab. Although primary IgE production was completely inhibited by FK506, secondary IgE production was not inhibited. Furthermore, IL-4 induction in plasma was only partially inhibited by FK506 when the A. suum extract-primed mice were resensitized with Ag. These results indicate that IL-4 produced by non-T cells plays a crucial role in secondary IgE production.

Critical involvement of interferon gamma in the pathogenesis of T-cell activation-associated hepatitis and regulatory mechanisms of interleukin-6 for the manifestations of hepatitis

A single intravenous injection of concanavalin A (Con A) induces T-cell activation and an acute hepatitis in mice. This study investigated the role of interferon gamma (IFN-gamma) in the pathogenesis of this hepatitis model. Striking increases in the plasma levels of various cytokines, including tumor necrosis factor (TNF), interleukin-2 (IL-2), and IFN-gamma, were detected before the increase in plasma aminotransferase levels induced by Con A injection. TNF levels peaked within 2 hours, whereas IFN-gamma levels peaked at 6 hours after Con A injection. In contrast to a sharp peak of TNF levels, high IFN-gamma levels were detected for a more prolonged period. Passive immunization with anti-IFN-gamma monoclonal antibody (MAb) conferred a dose-dependent protection against liver injury in this model. This protection was observed when anti-IFN-gamma MAb was administered at least 30 minutes before Con A injection but not when given 1 hour after Con A injection. The protection from Con A-induced hepatitis was also induced by administration of rIL-6 before Con A injection. rIL-6 treatment induced significant albeit incomplete inhibition of IFN-gamma and TNF production, whereas this regimen did not affect IL-2 production. Despite striking protective effects of rIL-6 or anti-IFN-gamma MAb, comparable levels of cellular (both T cell and polymorphonuclear cell) infiltration were detected in liver sections from animals untreated, or treated with either rIL-6 or anti-IFN-gamma MAb. Moreover, electron microscopic examination showed that infiltrating T cells exhibited a blastoid appearance in all groups. These results indicate that IFN-gamma plays a critical role in the development of Con A-induced acute hepatitis and suggest that IL-6 administration can regulate the manifestation of hepatitis through mechanisms including the reduced production of inflammatory cytokines such as IFN-gamma.

Completely impacted teeth in dentate and edentulous jaws

Panoramic radiographs from 1026 patients were examined for the presence of completely impacted teeth. The prevalence of completely impacted teeth in the edentulous jaw was lower than that in the dentate jaw in both the upper and lower jaws. The prevalence of completely impacted third molars in the edentulous jaw was also lower than that in the dentate jaw. However, there was no difference in the prevalence of completely impacted canine teeth and completely impacted anterior maxillary supernumerary teeth (mesiodens) in the edentulous jaw. These findings may indicate that completely impacted canine teeth and impacted anterior maxillary supernumerary teeth (mesiodens) are not influenced by the loss of erupted teeth.

Proprioceptive representation of the levator veli palatini muscle in the solitary nucleus of the rat

The levator veli palatini muscle is innervated by motoneurons of the glossopharyngeal nerve, which are located within the ambiguus nucleus; however, little is known about the afferent fibers of this muscle. A horseradish peroxidase study was conducted in rats following injection into the levator veli palatini muscle branch to reveal the location and the distribution of dendrites of the afferent fibers of the muscle. Terminal labels were densely distributed in the lateral region of the solitary nucleus, which receives afferents of the glossopharyngeal nerve, ipsilateral and contralateral to the injection site. The relationship of the levator veli palatini muscle with respiration was suggested by the localization of labeled terminals at sites where the afferents from the respiratory organs project densely, and by the demonstrated proprioceptive role of the afferent fibers passing through the muscle spindles contained in the levator veli palatini muscle.

[Successful combination chemotherapy including deoxycoformycin in a case of cutaneous T cell lymphoma]

A 44-year-old woman was admitted to our department because of fever and skin eruptions on August, 1991. Physical examination revealed superficial lymph node swelling, hepatosplenomegaly and generalized erythroderma. Laboratory findings were as follows; WBC 21,490/microliters with 67% lymphocytes including flower cells. The surface phenotype of lymphocytes was positive for CD2, CD4, CD25, CD29 suggesting helper-inducer T cell. Skin and lymph node biopsies revealed the infiltration of T cells with indented nuclei. Anti-HTLV-1 antibodies in the serum and HTLV-1 proviral DNA analysis by PCR method were negative. She was diagnosed as CTCL, and she was treated with prednisolone. However, her erythroderma deteriorated gradually, in spite of well-controlled lymphocyte counts. Combination chemotherapy, utilizing vincristine, etoposide and cyclophosphamide, was effective against organomegaly but not against generalized erythroderma. After DCF was initiated at a weekly dose of 7.5 mg, her erythroderma improved rapidly and markedly with the disappearance of severe itching, and she achieved complete remission. Our results suggest that DCF is beneficial for chemotherapy-resistant generalized erythroderma in CTCL.

Primary biliary cirrhosis complicated by severe hypoxemia

The case reported here is of a 61-year-old woman diagnosed with hepatopulmonary syndrome. She had had severe hypoxemia for 5 years. In room air, her arterial oxygen tension was low, and although we anticipated that treatment with oxygen would increase it, the treatment failed to do so. Pulmonary perfusion imaging with Tc-99m-labelled macroaggregated albumin showed an arterio-venous shunt in the lungs. Blood tests and liver scanning with Tc-99m-labelled galactosyl human serum albumin showed abnormalities of liver function, and per-rectal portal scintigraphy with Tc-99m pertechnetate showed severe portal hypertension. Inspection of a biopsy specimen taken under ultrasonographic guidance showed primary biliary cirrhosis of Scheuer stage I. The causes of hepatopulmonary syndrome are unknown, but seem to include a decrease in hepatic functional reserve, portal hypertension, or other factors. The development of hepatopulmonary syndrome due to portal hypertension in this patient is of interest.

Radiographic study of bone loss of mandibular lingual cortical plate accompanied by third molar development

OBJECTIVE

The purpose was to determine the features of mandibular lingual cortical bone loss around the root of the mandibular third molar.

STUDY DESIGN

We examined occlusal radiographs in 2210 persons aged 11 to 78 years.

RESULTS

Prominent increase of incidence of bone loss was evident in subjects in their third decade compared with those in their second decade. The incidence was not decreased into the sixties. The incidence of bone loss in men was significantly higher than that in women. The incidence was not influenced by inflammation around the tooth crown of the third molar, by tooth caries, or by metal fillings present in the third molar.

CONCLUSIONS

The present observations suggest that bone loss is induced by physiologic processes that accompany root formation of the third molar after mandibular growth.

Influence of adjacent teeth on impacted third molars in the upper and lower jaws

Panoramic radiographs of 1834 patients older than 21 years were evaluated for the prevalence of impacted teeth at different ages. The frequency of impacted teeth by age was constant, that is, the presence of completely impacted teeth could not be related to age. The interrelationship between the angulation of impacted teeth and the existence of adjacent teeth was studied in individuals older than 61 years. The angulation of most of the completely impacted teeth in the upper-third molar region was horizontal when adjacent teeth were not present, whereas impacted teeth in the upper-third molar region showed vertical angulation when adjacent teeth were present, suggesting that vertically impacted teeth may become exposed by bone resorption or infection and should be removed. The angulation of impacted lower third molars was horizontal irrespective of the presence of adjacent teeth. It appears that the interrelationship between the angulation of completely impacted teeth and the presence of adjacent teeth is different between the upper and lower third molar regions. The angulation of completely impacted teeth and the presence of adjacent teeth should be included in those criteria which determine whether or not completely impacted teeth should be removed.

Influences of tobacco smoke and vitamin E depletion on the distal lung of weanling rats

Tobacco smoke is associated with pulmonary emphysema via elastase-antielastase and oxidant-antioxidant imbalance. This study addressed the tobacco smoke-induced changes in the lungs of weanling rats with vitamin E depletion. Three-week-old Wistar rats fed on vitamin E-depleted or normal diet were intermittently exposed to tobacco smoke by Hamburg II machines for 4 weeks. Tobacco smoke significantly suppressed body weight increases, particularly in the vitamin E-depleted group. In the normal diet group, tobacco smoke induced emphysematous changes with significant increases in the mean linear intercept (Lm) and the destructive index (DI), which was supported by an increase in elastase-like activity and a decrease in elastase inhibitory capacity (EIC) in bronchoalveolar lavage (BAL) fluid. Vitamin E depletion alone altered neither Lm nor DI. In tobacco-exposed animals in addition to vitamin E depletion, elastase-like activity, EIC in BAL fluid and DI were comparable to that in tobacco-exposed animals on a normal diet. However, Lm was markedly decreased with thickened epithelium and shrunk alveolar space. These results suggest that vitamin E depletion, when linked to tobacco exposure, might induce impaired lung development in the weanling rats, which is different from the emphysematous changes.

Supernumerary impactions of the mandibular cuspids and bicuspids. Case report

A case involving the presence of supernumerary cuspids and bicuspids is described. The condition was probably an inherited one because of the family history and the bilateral incidence. The supernumerary teeth erupted because of alveolar resorption in which inflammatory factors probably played a role. Radiographic follow-up of the site of supernumerary impacted teeth and alveolar resorption should be undertaken.

The distribution of afferent neurons in the trigeminal mesencephalic nucleus and the central projection of afferent fibers of the mylohyoid nerve in the rat

Horseradish peroxidase conjugated to wheatgerm agglutinin (HRP:WGA) was injected into the proximal cut ends of three branches of the mylohyoid nerve in rats: the branch to the mylohyoid muscle (BrMh), the branch to the anterior belly of the digastricus muscle (BrDg), and the cutaneous branch (BrCu). HRP-labeled cells were detected in the ipsilateral caudal portion of the trigeminal mesencephalic nucleus (Vmes) and the ipsilateral ventromedial division of the trigeminal motor nucleus, except when HRP:WGA was applied to the BrCu. Morphologically, all labeled Vmes cells were of the pseudounipolar type. Projections of the primary afferents of the BrMh were observed in the ipsilateral trigeminal nucleus caudalis, the upper cervical dorsal horns of laminae I-III, and the dorsolateral recticular formation (Rf), whereas the primary afferents of the BrDg terminated in the ipsilateral trigeminal nucleus principalis and Rf. These observations suggest that the role of the afferent inputs of the mylohyoid muscle differs from that of those of the anterior belly of the digastricus muscle in terms of several functions associated with jaw-closing and infrahyoid muscles.

Appearance of fracture caused by emphysema

A case presenting radiographic appearance of a fracture line associated with emphysema which occurred in the removal of a mandibular third molar is reported. The cause of the fracture line in the radiograph is discussed together with the benefit of CT in diagnosis.

MDCK cell cultures supplemented with high concentrations of trypsin exhibit remarkable susceptibility to influenza C virus

Multiplication of influenza C virus in MDCK cell cultures increased with increasing concentrations of trypsin up to 160 micrograms/ml, whereas maximum growth of influenza A virus in the same culture was observed at a concentration of 10 micrograms/ml. In the presence of 160 micrograms of trypsin per ml MDCK cells showed the same or even higher susceptibility to various strains of influenza C virus compared with HMV-II cells, a human melanoma cell line that has been reported to have high susceptibility to the virus. Complete cleavage of the HE precursor protein of MDCK-grown influenza C virus into HE1 and HE2 subunits was achieved by trypsin at a concentration of 160 micrograms/ml, whereas only partial cleavage was observed at 10 micrograms/ml. The present results thus demonstrate that MDCK cell cultures supplemented with trypsin at a concentration of 160 micrograms/ml become highly susceptible to influenza C virus.

Use of prostaglandin I2 analog in treatment of massive hepatic necrosis associated with endothelial cell injury and diffuse sinusoidal fibrin deposition

Endothelial cell damage causes massive hepatic necrosis as a result of fibrin deposition in the hepatic sinusoids. When a stable analog of prostaglandin I2, beraprost sodium, was administered to rats given either dimethylnitrosamine, carbon tetrachloride, or endotoxin following Corynebacterium parvum administration, the hepatic necrosis produced in each was attenuated, but to a greater extent in the dimethylnitrosamine and endotoxin/Corynebacterium parvum models, where fibrin deposition in the hepatic sinusoids occurs, as compared to the carbon tetrachloride model, where such fibrin deposition does not occur. Beraprost sodium reduced the expected increase of portal venous pressure in the endotoxin/Corynebacterium parvum model without affecting plasma thrombin-antithrombin III complex levels. Beraprost sodium also significantly reduced cell killing of both isolated rat hepatocytes and hepatic sinusoidal endothelial cells exposed to tert-butyl hydroperoxide when compared to controls. Beraprost sodium could prove to be a therapeutic candidate for the treatment of hepatic necrosis, particularly in cases associated with fibrin deposition in the hepatic sinusoids because of its fibrin clot-clearing action.

Early evaluation of necrotizing fasciitis with use of CT

Gas bubbles are one of the important signs in the clinical diagnosis of necrotizing fasciitis, and radiographs are mandatory. An instance where gas bubbles not found on the plain radiographs were clearly shown by CT, which is a useful method for close monitoring and decompression of gas bubbles situated deeply in the spaces of the maxillo-facial and neck regions.

Responsiveness of single afferents in the infraorbital nerve to oral air pressures generated by consonants

The responsiveness of receptors supplying the oral mucosa to air pressures generated during consonant production was investigated to obtain information about hypothetical mechanisms underlying speech deficits. The delay between the onset of the neural discharge and the pop puff of phonation (mouth-exist pressure) for /pa/ production was significantly shorter and less variable than it was for /ta/ and /ka/ production, suggesting that the discharge is more closely coupled to the onset of /pa/ production. The data were interpreted to imply that single fibers of the infraorbital nerve respond to the build-up of oral air pressure during /pa/ production. This, and similar sensory information, may be used by the central neural mechanisms which monitor and control the air pressures required for phonation.