Clinical application of endoscopic soft palate augmentation in the treatment of velopharyngeal insufficiency

Velopharyngeal structure augmentation with the injection of autologous fat tissue into the nasal mucosa of the soft palate has been reported previously. However, as the injection points in the velopharyngeal space cannot be observed directly, these injections may be difficult to perform accurately. This report describes a new endoscope-assisted approach in which the materials for velopharyngeal structure augmentation are administered while observing the injection points directly, also enabling adjustment of the amount of material injected. A case series of five patients aged 8-16 years who underwent endoscopic soft palate augmentation under general anaesthesia is reported. Autologous fat tissue was injected into the nasal mucosa of the soft palate using a needle-type device of an endoscope, and the effects of the treatment were evaluated. The injections were performed successfully, and the velopharyngeal function was improved. This new technique of endoscopy-assisted augmentation was useful for the treatment of velopharyngeal insufficiency.

A cross-sectional study of relationships between periodontal disease and general health: The Hitachi Oral Healthcare Survey

BACKGROUND

This cross-sectional study performed to clarify the relationship between periodontal disease and non-communicable diseases (NCDs), such as obesity, diabetes mellitus, impaired glucose tolerance (IGT), chronic obstructive pulmonary disease (COPD), and atherosclerotic cardiovascular disease (ASCVD) by introducing dental examinations into the annual health examinations conducted by Japanese companies, and to highlights the importance of a medical system that connects dental and medical professionals.

METHODS

A total of 1.022 Hitachi Ltd. employees were enrolled in this cross-sectional study. We examined correlations and odds ratios (ORs) between the dental and overall health of employees using stratification and multiple logistic regression analyses based on the periodontal health indicators, general health indicators, and occlusal force.

RESULTS

The adjusted OR of PPD for obesity (OR, 1.42; 95% confidence interval [CI], 1.09-1.84; p = 0.009), IGT (OR, 1.48; 95% CI, 1.00-2.20; p = 0.049), and COPD (OR, 1.38; 95% CI, 1.02-1.88; p = 0.038) significantly differed. The adjusted OR of body mass index (OR, 1.28; 95% CI 1.15-1.42; p < 0.001), haemoglobin A1C (HbA1c) (OR, 4.34; 95% CI, 1.89-9.98; p < 0.001), fasting blood glucose (FBG) levels (OR, 1.08; 95% CI 1.04-1.11; p < 0.001), postbronchodilator forced expiratory volume in one second/forced vital capacity ratio (%FEV1) (OR, 0.95; 95% CI 0.91-1.00; p = 0.031) and smoking (OR, 2.32; 95% CI 1.62-3.33; p < 0.001) for severe periodontal disease also significantly differed. Occlusal force was significantly reduced in employees aged 50-59 years compared to those aged 40-49 years. Both PPD, HbA1c, FBG levels were significantly associated with occlusal force among employees with moderate/severe periodontitis. PPD was significantly associated with occlusal force among employees with and moderate COPD, and ASCVD. %FEV1 was significantly associated with occlusal force among employees with IGT.

CONCLUSIONS

This cross-sectional study revealed mutual relationships among periodontal disease, NCDs, and occlusal force on Japanese corporate workers. We demonstrated that a comprehensive, regional healthcare system centred on annual integrated dental and physical health examinations in the workplace will benefit employees and positively impact corporate health insurance.

Influence of Olfactory Function on Appetite and Nutritional Status in the Elderly Requiring Nursing Care

OBJECTIVE

To investigate olfactory function in elderly subjects requiring nursing care to clarify its association with appetite and nutritional status.

SETTING

Facility for the elderly requiring nursing care.

PARTICIPANTS

The subjects were 158 elderly people requiring nursing care and 37 elderly people not requiring nursing care.

MEASUREMENTS

Experiment I: Olfactory function and factors (cognitive function, appetite, and nutritional status) that may be associated with it were compared between the elderly subjects requiring nursing care and those not requiring nursing care using covariance analysis in consideration of age. For evaluation, the OSIT-J was used for olfactory function, the HDS-R for cognitive function, the CNAQ for appetite, and BMI for nutritional status. Experiment II: The subjects were the same elderly subjects requiring nursing care in Experiment I, and food intake was surveyed in addition to the OSIT-J, HDS-R, CNAQ, and BMI. A univariate linear regression analysis was performed with OSIT-J as the response variable, and age, HDS-R, CNAQ, BMI, and food intake as the explanatory variables.

RESULTS

Experiment I: On covariance analysis, the OSIT-J score was significantly lower for the elderly subjects requiring nursing care than for those not requiring nursing care (p<0.01). The mean score was 8 or lower in both groups, demonstrating lower olfactory function in both groups. Regarding factors that may be associated with olfactory function, a significant difference was noted in the HDS-R (p<0.01), confirming significantly lower cognitive function in the elderly subjects requiring nursing care. No significant difference was noted in the CNAQ or BMI. Experiment II: On a univariate linear regression analysis, an association with the OSIT-J was noted for age and HDS-R. Age was inversely correlated and the HDS-R was positively correlated. Factors associated with lower olfactory function in the elderly subjects requiring nursing were age and cognitive function, whereas appetite, nutritional status, and food intake were not associated.

CONCLUSION

Olfactory function in elderly subjects requiring nursing care was poorer than that in those not requiring nursing care, suggesting that aging and cognitive decline are associated with lower olfactory function. In addition, no association of lower olfactory function with appetite, nutritional status, or food intake was noted in the elderly subjects requiring nursing care.

Sarcopenia, the depletion of muscle mass, an independent predictor of respiratory complications after oncological esophagectomy

Surgery for esophageal carcinoma is known to be associated with high morbidity. Recent studies have reported a correlation of nutritional and inflammatory parameters with postoperative course. This study aims to clarify the risk factors for operative morbidity after resection of esophageal carcinoma. Consecutive patients who underwent esophagectomy for esophageal squamous cell carcinoma at our institute were included (n = 102; 89 males and 13 females; mean age: 67.3 years). Clinicopathological characteristics, presence or absence of sarcopenia, and modified Glasgow prognostic score were assessed, and their correlation with postoperative complications was investigated using univariate and multivariate analyses. Sarcopenia was defined using a combination of muscle mass area and body mass index. Of the included 102 patients, 45 (44.1%) exhibited sarcopenia (sarcopenia group), while 57 (55.9%) did not (non-sarcopenia group). No significant difference was observed between the groups regarding surgical procedures and tumor stage; furthermore, there was no mortality. Twenty-six patients developed respiratory complications (including 20 cases of pneumonia). On univariate analysis, sarcopenia, modified Glasgow prognostic score, and American Society of Anesthesiologists physical status were found to be significantly associated with the development of postoperative respiratory complications. On multivariate analysis, sarcopenia was found to be an independent risk factor for postoperative respiratory complications after esophagectomy. We believe that identifying patients at risk and providing preoperative nutritional support as well as physical therapy aimed at strengthening of body muscles may help reduce the incidence of postoperative respiratory complications in such patients.

Dental Treatment Effect on Deep Brain Stimulation System in Parkinson's Disease

Parkinson's disease (PD) is a highly prevalent, long-term neurodegenerative disorder that is sometimes treated by deep brain stimulation (DBS), which significantly reduces the need for dopaminergic drug therapy and improves quality of life. Such patients are cautioned, however, that dental instruments such as a dental turbine or ultrasonic scaler may adversely affect the functioning of such a system. Here, we report dental treatment for right maxillary tooth pain in a 65-year-old woman undergoing DBS for PD. The diagnosis was occlusal trauma. After verification with occluding paper each time, treatment comprised milling of the high contact points of tooth #17, followed by scaling with an ultrasonic scaler. This treatment was spread out over 3 visits, and its course was uneventful. To our knowledge, there are no previous reports on the interaction between dental instruments and DBS systems. Although no interference with the DBS system was observed here, we believe that the dentist should be aware of the potential for such, especially with the use of devices used to measure root canal length, dental lasers, and electrical scalpels.

Epigenetics as a mechanism linking developmental exposures to long-term toxicity

A variety of experimental and epidemiological studies lend support to the Developmental Origin of Health and Disease (DOHaD) concept. Yet, the actual mechanisms accounting for mid- and long-term effects of early-life exposures remain unclear. Epigenetic alterations such as changes in DNA methylation, histone modifications and the expression of certain RNAs have been suggested as possible mediators of long-term health effects of environmental stressors. This report captures discussions and conclusions debated during the last Prenatal Programming and Toxicity meeting held in Japan. Its first aim is to propose a number of criteria that are critical to support the primary contribution of epigenetics in DOHaD and intergenerational transmission of environmental stressors effects. The main criteria are the full characterization of the stressors, the actual window of exposure, the target tissue and function, the specificity of the epigenetic changes and the biological plausibility of the linkage between those changes and health outcomes. The second aim is to discuss long-term effects of a number of stressors such as smoking, air pollution and endocrine disruptors in order to identify the arguments supporting the involvement of an epigenetic mechanism. Based on the developed criteria, missing evidence and suggestions for future research will be identified. The third aim is to critically analyze the evidence supporting the involvement of epigenetic mechanisms in intergenerational and transgenerational effects of environmental exposure and to particularly discuss the role of placenta and sperm. While the article is not a systematic review and is not meant to be exhaustive, it critically assesses the contribution of epigenetics in the long-term effects of environmental exposures as well as provides insight for future research.

Endoscopic evaluation of food bolus formation and its relationship with the number of chewing cycles

It is known that solid food is transported to the pharynx actively in parallel to it being crushed by chewing and mixed with saliva in the oral cavity. Therefore, food bolus formation should be considered to take place from the oral cavity to the pharynx. In previous studies, the chewed food was evaluated after the food had been removed from the oral cavity. However, it has been pointed out that spitting food out of the oral cavity interferes with natural food bolus formation. Therefore, we observed food boluses immediately before swallowing using an endoscope to establish a method to evaluate the food bolus-forming function, and simultaneously performed endoscopic evaluation of food bolus formation and its relationship with the number of chewing cycles. The subject was inserted the endoscope nasally and instructed to eat two coloured samples of boiled rice simultaneously in two ingestion conditions ('as usual' and 'chewing well'). The condition of the food bolus was graded into three categories for each item of grinding, mixing and aggregation and scored 2, 1 and 0. The score of aggregation was high under both ingestion conditions. The scores of grinding and mixing tended to be higher in subjects with a high number of chewing cycles, and the score of aggregation was high regardless of the number of chewing cycles. It was suggested that food has to be aggregated, even though the number of chewing cycles is low and the food is not ground or mixed for a food bolus to reach the swallowing threshold.

Swallowing frequency in elderly people during daily life

Disuse atrophy of swallowing-related organs due to an excessive decrease in swallowing frequency is suspected to occur in patients with poor oral intake, especially elderly people. However, swallowing frequency in daily life has not previously been examined in the elderly. This study examined swallowing frequency in elderly people and compared these findings to those in a younger population and differences in the degree of activity in daily life. (i) We compared swallowing frequency in 20 elderly people (82·0 ± 8·3 year) and 15 healthy young people (26·5 ± 3·5 year). (ii) 20 elderly people were divided into two groups according to the degree of activity in daily life: a semi-bedridden group and bedridden group; the swallowing frequency was compared between these groups. (i) The swallowing frequency in the elderly people was 2-19 times per hour and the mean was 9·4 ± 4·9, and that in the healthy young people was 16-76 times per hour and the mean was 40·7 ± 19·5. Swallowing frequency in elderly people was significantly lower than that in young healthy people (P < 0·0001). (ii) The swallowing frequency in bedridden group was 2-11 times per hour and the mean was 6·8 ± 3·3, and that in semi-bedridden group was 3-19 times per hour and the mean was 11·9 ± 5·1. Swallowing frequency in bedridden group was significantly lower than that in semi-bedridden group (P < 0·05). These results indicate that in daily life, elderly people tend to swallow less frequently than young people. In addition, swallowing frequency was lower in elderly subjects with a low degree of activity in daily life.

Development of a swallowing frequency meter using a laryngeal microphone

Disuse atrophy of swallowing-related organs is suspected when decreased swallowing frequency is seen in the elderly. However, swallowing frequency has not been examined in elderly people during daily life. We developed a swallowing frequency meter containing a laryngeal microphone that does not restrict the subject's ability to perform daily activities. In this study, the utility of the meter was assessed. Experiment 1: The ability of the meter to detect swallowing was examined. The subject was instructed to swallow saliva or foods at a voluntarily pace. During these procedures, swallowing events were simultaneously recorded by the meter, self-enumeration and videofluorography. As a result, all of the swallowing events identified by the meter coincided with the swallowing events identified by self-enumeration and videofluorography. Experiment 2: Swallowing sounds display various patterns both between and within individuals. Therefore, we examined the concordance rate between the number of swallowing events counted by the meter and that counted by self-enumeration in 15 subjects over a longer period than in experiment 1. The concordance rates calculated by two examiners between the meter and self-enumeration were 96·8 ± 4·5% and 98·9 ± 3·3% at rest and 95·2 ± 4·5% and 96·1 ± 4·1% during meals, respectively. Our findings indicate that this meter is useful for measuring the frequency of swallowing during daily situations.

Permanent genetic resources added to Molecular Ecology Resources Database 1 October 2010-30 November 2010

This article documents the addition of 277 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Ascochyta rabiei, Cambarellus chapalanus, Chionodraco hamatus, Coptis omeiensis, Cynoscion nebulosus, Daphnia magna, Gerbillus nigeriae, Isurus oxyrinchus, Lates calcarifer, Metacarcinus magister, Oplegnathus fasciatus, Pachycondyla verenae, Phaethon lepturus, Pimelodus grosskopfii, Rotylenchulus reniformis, Scomberomorus niphonius, Sepia esculenta, Terapon jarbua, Teratosphaeria cryptica and Thunnus obesus. These loci were cross-tested on the following species: Austropotamobius italicus, Cambarellus montezumae, Cambarellus puer, Cambarellus shufeldtii, Cambarellus texanus, Chionodraco myersi, Chionodraco rastrospinosus, Coptis chinensis, Coptis chinensis var. brevisepala, Coptis deltoidea, Coptis teeta, Orconectes virilis, Pacifastacus leniusculus, Pimelodus bochii, Procambarus clarkii, Pseudopimelodus bufonius, Rhamdia quelen, Sepia andreana, Sepiella maindroni, Thunnus alalunga, Thunnus albacares, Thunnus maccoyii, Thunnus orientalis, Thunnus thynnus and Thunnus tonggol.

Alpha2-adrenoceptors coordinate swallowing and respiration

Because the discoordination between swallowing and respiration may cause severe respiratory disorders such as aspiration pneumonia, understanding the neuronal mechanisms underlying such coordination is important. Recently, it was reported that medullary noradrenergic neurons are involved in evoking esophageal-gastric relaxation reflex, leading to a hypothesis that such neurons are also involved in swallowing-respiration coordination. We tested this hypothesis using an in vitro brain-stem preparation obtained from neonatal rats. A temporal inhibition of respiratory rhythm was consistently observed when swallowing activity was induced by electrical stimulations to the supralaryngeal nerve. We found that a broad adrenergic receptor agonist, norepinephrine, markedly blocked the swallowing-induced temporal inhibition of respiration. Further studies revealed that swallowing-induced respiratory inhibition is blocked by an alpha2-adrenergic receptor agonist and enhanced by an alpha2-adrenergic receptor antagonist, indicating an important role of alpha2-adrenergic receptors in regulation of the coordination between swallowing and respiration in vitro.

Effect of a speech aid prosthesis on reducing muscle fatigue

It has been reported that the levator veli palatini muscles of speakers with velopharyngeal incompetence tend to demonstrate muscle fatigue during speech. This study examined whether a speech aid prosthesis might reduce levator muscle fatigue in such speakers. Eight individuals with post-surgical cleft palates, and who wore a speech aid prosthesis, were studied. Each person was asked to pronounce the syllable [pu] more than 50 times. Mean power frequency (MPF) of one syllable was obtained from electromyographic data from the levator muscle. The MPF regression line was calculated during the course of syllable repetition. The absolute values of the slopes of the regression lines with the prosthesis were significantly smaller than those without the prosthesis. It was shown that the prosthesis reduced the decrease in MPF during speech. These results suggested that speech aid prostheses reduce levator muscle fatigue during speech in persons with velopharyngeal incompetence.

Effect of a single oral dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin on immune function in male NC/Nga mice

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces immunosuppression in humans and animals. However, the effect of TCDD on Th2-type immune responses such as allergic reactions has been unclear. Using NC/Nga mice that developed atopic dermatitis-like skin lesions with marked elevation in plasma of total IgE when bred under conventional conditions, we investigated the effects of a single oral dose of TCDD on immune responses. NC/Nga mice received a single oral dose (0 or 20 microg/kg body weight) of TCDD. On day 7, treatment with TCDD alone decreased the cellularity of thymus. However, treatment with TCDD modified the cellularity of spleens and mesenteric lymph nodes (MLNs) but not of the thymus on day 28. When NC/Nga mice received ip immunization with OVA and alum on the same day as the TCDD treatment (0, 5, or 20 microg/kg body weight), TCDD markedly suppressed the concentrations of Th2-type cytokines (e.g., IL-4 and IL-5) in culture supernatants of spleen cells, whereas IFN-gamma production significantly increased. TCDD exposure reduced anti-OVA and total IgE antibody titers in plasma and did not induce the development of atopic dermatitis-like lesions in the pinnae or dorsal skin of NC/Nga mice. These results suggest that in NC/Nga mice, exposure to TCDD may impair the induction of Th2-type immune responses.

Change in levator veli palatini muscle activity of normal speakers in association with elevation of the velum using an experimental palatal lift prosthesis

OBJECTIVE

The purpose of this study was to examine whether mechanical elevation of the velum can directly affect the levator veli palatini muscle (LVP) activity using normal speakers as subjects.

DESIGN

Each subject was instructed to produce /mu/, /u/, /pu/, /su/, and /tsu/ in a speech task and to blow with maximum possible effort. Smoothed electromyographic activity of the LVP was recorded with an experimental palatal lift prosthesis (PLP) both in place and removed.

PARTICIPANTS

Four normal speakers were used as subjects.

RESULTS

LVP activity for all tasks was significantly smaller (p <.001; Student's t test) with the PLP in place than without the PLP for all subjects. An analysis of variance (p <.001) clarified that activity ranges of the LVP were significantly different between the removal and placement conditions for all the subjects.

CONCLUSION

The result was similar to that previously obtained for patients with velopharyngeal incompetence wearing a PLP. It is possible that the decrease in the LVP activity in association with placement of a PLP is caused by the direct effect of mechanical elevation, which decreases the distance the velopharyngeal mechanisms must travel for complete closure of the velopharynx.

Induction of the imbalance of helper T-cell functions in mice exposed to diesel exhaust

Administration of diesel exhaust particles (DEP) increases antigen-specific IgE production and IgE-secreting cells, and induces Th2-type cytokine profiles in the airway in mice and humans. To determine the early effects of diesel exhaust (DE) inhalation on the cytokine production profile, BALB/c mice were exposed to 0 (controls) and 1.0 mg/m3 DE inhalation for 4 weeks. Intraperitoneal sensitization with ovalbumin (OVA) was conducted immediately before DE inhalation. Mice were treated with anti-CD4 or anti-CD8 mAb 1 day before and after the sensitization. On day 21, these mice were boosted with OVA and blood; bronchoalveolar lavage (BAL) fluid, and spleens were collected on day 28. In BAL fluid, both TNFalpha and IL-10 production in DE-exposed and control mice remained basically the same. IL-6 production in the anti-CD4 treatment group of DE-exposed mice, however, significantly increased compared with that of the controls. In vitro antigen-stimulated interleukin-4 (IL-4) and -10 (IL-10) production in spleen cells of exposed mice were not affected by low-dose DE inhalation. In vitro interferon (IFN)-gamma production in the anti-CD4 treated group of exposed mice decreased markedly. Although anti-OVA IgE production in the plasma of sham-treated mice exposed to DE was the same level as for controls, anti-CD4 mAb treatment in DE-exposed mice significantly reduced IgE production compared to controls. In anti-OVA IgG1 production, anti-CD4 or anti-CD8 mAb treatment in DE-exposed groups also significantly reduced. Anti-OVA IgG2a production was reduced by treatment with anti-CD4 mAb, but increased by anti-CD8 mAb treatment in DE-exposed mice. Low dose DE inhalation is thus shown to adversely affect the cytokine and antibody production in mice by altering CD4+ and CD8+ T-cell functions.

Roles of CD4+ and CD8+ T cells in adjuvant activity of diesel exhaust particles in mice

Through an imbalance in Th1 and Th2 cytokine profiles, diesel exhaust particles (DEP) are thought to induce Th2-dominated IgE and IgG1 production. However, the roles of CD4+ and CD8+ T-cell subtypes in the increased immune responses to antigen in mice exposed to DEP are unclear. In the present study, we investigated whether treatment with anti-CD4 or anti-CD8 mAb abrogated the adjuvant activity of DEP. On day -1 and day 1, each group of mice was injected intraperitoneally with anti-CD4, anti-CD8, or rat IgG (vehicle). On day 0, the mice were immunized with ovalbumin (OVA) or OVA plus DEP. After 3 weeks, each mouse was boosted with 10 microg of OVA alone. On day 7 after the first injection with OVA+DEP or OVA alone, the numbers of total, IA+, CD80+/IA+ and CD86+/IA+ cells in peritoneal exudate cells (PEC) were higher in OVA+DEP-immunized mice than in OVA-immunized mice. Depletion of CD8+ cells resulted in a modulation of the production of granulocyte-macrophage colony-stimulating factor, IL-12 and PGE(2) in peritoneal exudate fluid from OVA+DEP-immunized mice. On day 28, DEP injection markedly increased IL-4 production in the culture supernatants of spleen cells from CD4+ or CD8+-depleted mice. Depletion of CD8+ cells in OVA+DEP-immunized mice resulted in a decrease in IFN-gamma production compared with that in OVA-immunized mice. Adjuvant activity of DEP was observed in anti-OVA IgE, anti-OVA IgG1, anti-OVA IgG3, and total IgE production. Depletion of CD4+ T cells abrogated the adjuvant effect of DEP on anti-OVA IgE, and anti-OVA IgG1 production in plasma. However, depletion of CD8+ T cell inhibited the upregulated anti-OVA IgG3 production. These findings suggest that DEP injection may affect not only the function of CD4+ cells but also that of CD8+ T-cell subsets to modulate the synthesis of proinflammatory cytokine in PEC and type-1 and type-2 cytokine production in spleens.

Cl atom-initiated oxidation of three homologous methyl perfluoroalkyl ethers

Chlorine atom-initiated photooxidations of three homologous methyl perfluoroalkyl ethers (HFEs), n-C(n)F(2n+1)OCH3 (n = 2, 3, and 5), in air in the absence of NOx were investigated with a long path FTIR/photochemical reaction system to elucidate the degradation mechanisms. The environmental removal processes of these three ethers in the troposphere were estimated. For oxidation of the three ethers, perfluoroalkyl formates (C(n)F(2n+1)OCHO; n = 2, 3 and 5) as relatively stable intermediates were produced at unity of the production ratio, which was independent of the perfluoroalkyl length. The rate constants for the reaction of Cl atoms with C2F5OCHO, C3F7OCHO, and C5F11OCHO were (1.2 +/- 0.5) x 10(-14), (1.2 +/- 0.5) x 10(-14), and (1.8 +/- 0.7) x 10(-14) cm3 molecule(-1) s(-1), respectively. The rate constants of the reaction of Cl with produced perfluoroalkyl formates were larger than these of perfluoroalkyl ethers. The formyl group of the perfluoroalkyl formates was finally converted to carbon dioxide. The -CF2- of the perfluoroalkyl groups for the three ethers was mainly converted to COF2 through the C-C cleavage; the conversion ratios from the carbons of the perfluoroalkyl group to COF2 were 48 +/- 10, 76 +/- 10, and 60 +/- 10% for C2F5OCH3, n-C3F7OCH3, and n-C5F11OCH3, respectively. Sixteen percent of the perfluoroalkyl group for n-C3F7OCH3 was converted to C2F5COF. Similarly, the perfluoroalkyl group of n-C5F11OCH3 was converted to C(n)F(2n+1)COF (n = 2, 3, and/or 4) with the yield of 15-30%, while for C2F5OCH3, the formation of CF3COF was not confirmed. As an oxidation product of the terminal CF3- group, 20, 22, and 16% of the CF3 group for C2F5OCH3, n-C3F7OCH3, and n-C5F11OCH3, respectively, were converted to CF3OOOCF3.

The effects of perinatal exposure to low doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin on immune organs in rats

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is revealed to exert diverse biological effects including immunotoxicity, mainly by inadvertently activating the transcription factor arylhydrocarbon receptor (AhR). In the present study, the developmental effects of perinatal exposure to low doses of TCDD on the major immune organs of offspring, thymus and spleen, were investigated focusing on weaning time (postnatal day (PND) 21), puberty (PND 49) and adulthood (PND 120) in male rats. Concurrently, TCDD contents in those organs were measured with a high-resolution gas chromatography-mass spectrometry (GC/MS). In the thymus and spleen, CYP1A1 mRNA induction, the sensitive reaction caused by activation of AhR, was also measured in order to examine whether perinatally administered TCDD can elicit gene expressions in these organs. When pregnant dams were administered a single oral dose of 12.5-800 ng TCDD/kg body weight on gestation day (GD) 15, the weights of the thymus and spleen of the offspring did not differ from those of control animals throughout the experiments. The thymus and spleen maternally exposed to 800 ng TCDD/kg contained 102.0 and 62.7 pg TCDD/g tissue on PND 21, respectively, and the amounts decreased thereafter. In the thymus, dose-dependent CYP1A1 mRNA induction was clearly observed by maternal exposure to 50-800 ng TCDD/kg on PND 5. The induction was gradually decreased on PND 21 and 49. On the other hand, CYP1A1 mRNA induction in the spleen was very weak. In these thymi, no reproducible change was observed by TCDD exposure in cell number and cellular population defined by CD4 and CD8 molecules at any time. In contrast, splenocyte number was shown to decrease by maternal exposure to 12.5-800 ng TCDD/kg in a dose-dependent manner on PND 49. The alteration in spleen cellularity by TCDD was not detected on PND 21 or 120. These results clarified that perinatal exposure to low doses of TCDD affects the immune organs, which is apparent in spleen around puberty and likely to be hardly relevant to AhR-dependent gene expressions.

Effect of placement of a speech appliance on levator veli palatini muscle activity during speech

OBJECTIVE

The purposes of this electromyographic study were to examine whether levator veli palatini muscle activity during speech can be changed with placement of a speech appliance and to clarify whether or not the change is related to the type of speech appliance used.

DESIGN

Electromyography (EMG) was performed during production of speech samples in two conditions: with placement and with removal of a speech appliance. Speech samples were the vowel /omega/ and consonant-vowel (omega) syllables, including nasal, plosive, fricative, and affricate consonants.

SETTING

Division for Oral-Facial Disorders, Faculty of Dentistry, Osaka University Dental Hospital, Japan.

PARTICIPANTS

Subjects were six patients with repaired cleft palate and velopharyngeal inadequacy (VPI); three routinely wore a palatal lift prosthesis to correct borderline VPI, and the other three wore a speech appliance hybrid that consisted of a pharyngeal bulb and a palatal lift.

INTERVENTIONS

Each patient was asked to produce each speech sample in both conditions of placement and removal of their respective appliances.

MAIN OUTCOME MEASURES

Smoothed EMG signals of the levator veli palatini muscle were recorded with and without the appliance during five repetitions of each speech sample. The average value of peak smoothed levator EMG was compared between placement and removal conditions for all subjects and between the two subject groups in each experimental condition.

RESULTS

With a speech appliance in place, the range of levator activity was distributed in a portion lower than that in the removed condition for subjects in both appliance groups. In addition, the intervals were smaller in the placement condition than in the removed condition.

CONCLUSION

A speech appliance may prevent hypernasality, nasal emission of air, or both associated with VPI because of mechanical obturation of the velopharynx and an alteration in velopharyngeal function.

Induction of apoptosis in mouse thymocytes by cadmium

In the thymus apoptosis is an important process in T cell maturation and differentiation. Cadmium (Cd) is an ubiquitous toxic metal that is capable of modulating immune responses. To investigate the induction of apoptosis and immunomodulation by environmental chemicals, we cultured mouse thymocytes with Cd and/or dexamethasone (DEX). DNA fragmentation was analyzed by gel electrophoresis, ELISA and flow cytometry. Treatment with either Cd or DEX induced DNA fragmentation in the thymocytes. Exposure to 10 microM Cd killed thymocytes by apoptosis rather than necrosis. However, no synergistic or additive effect was observed in the induction of apoptosis when DEX was added to the Cd. These results suggest that Cd may modulate the function of the thymus by the induction of apoptosis through mechanisms that differ from those used by DEX.

Alterations of thymocyte development, thymic emigrants and peripheral T cell population in rats exposed to 2,3,7, 8-tetrachlorodibenzo-p-dioxin

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) exerts diverse biological effects by activating the cytosolic transcription factor, arylhydrocarbon receptor (AhR), which translocates to nuclei by TCDD binding and induces gene expressions. Among the well known-adverse effects of TCDD is thymus atrophy. In thymus atrophy, TCDD alters the proliferation as well as the differentiation of immature thymocytes. Previous studies on the effects of TCDD on thymocyte development were primarily carried out with high doses of TCDD. The present study investigates the effects of lower doses of TCDD (1 or 2 microg TCDD/kg by gavage) on thymocyte development, and furthermore, their sequential consequences on the peripheral T cell repertoire. Seven days after treatment with 1 or 2 microg TCDD/kg, the expression of CYP1A1 mRNA, one of the sensitive responses caused by the binding of TCDD to AhR, was detected in the thymus of rats. Thymus weights and thymus cell numbers decreased in TCDD-treated rats in a dose-dependent manner. The ratios of CD4 single-positive (SP) cells/CD8 SP cells were significantly reduced by TCDD exposure, indicating that the maturation of CD4(+)CD8(+) double-positive (DP) cells was skewed toward CD8 SP cells. These changes in the thymus were parallel to those previously observed with high doses of TCDD exposure. However, the specific reduction of DP cells reported in previous studies with high doses of TCDD was not detected in the present study. On the other hand, the skewing of mature CD4/CD8 T cell ratio in thymocytes by TCDD was not reflected in mesenteric lymph node (LN) lymphocytes, where the proportion of CD8 T cells was rather lowered by TCDD with a significant difference at 1 microg TCDD/kg. In LN lymphocytes, the percentage of recent thymic emigrants (RTEs), defined by the surface markers of Thy1(+)CD45RC(-), was shown to be significantly reduced by exposure to 1 and 2 microg TCDD/kg. T cell supply from the thymus has a crucial role in keeping the diversity of the T cell repertoire. The results of the present study indicated that lower doses of TCDD affect thymocyte development, especially differentiation, and reduce the proportion of RTE in LN, which may cause immunosuppression by reducing the variety of the T cell receptor repertoire.

Effect of placement of a speech appliance on levator veli palatini muscle activity during blowing

OBJECTIVE

We have observed clinically that some speakers wearing a speech appliance for correction of velopharyngeal incompetence can blow with variable intensity without nasal air escape. This clinical finding suggests that tightness of velopharyngeal closure may be regulated in accordance with oral air pressure during blowing. The purposes of this electromyographic study were (1) to examine whether levator vell palatini muscle activity can be changed in relation to oral air pressure during blowing when the speech appliance is removed, (2) to clarify whether or not the change is related to the severity of velopharyngeal incompetence, and (3) to examine whether placement of a speech appliance can alter levator muscle activity into the equivalent of that of normal speakers during blowing.

DESIGN

Eight patients with repaired cleft palate, who routinely wear a palatal lift prosthesis (PLP) or a hybrid speech appliance of a pharyngeal bulb and palatal lift (bulb-PLP), served as subjects. Subjects were classified into one of two groups according to their speech appliance (PLP group and bulb-PLP group). Electromyography of the levator veli palatini muscle was recorded with a speech appliance in place and then with the speech appliance removed as the subject blew through a tube at three different effort levels.

RESULTS

In the removed condition, the change in levator activity in relation to oral air pressure was variable across subjects in the bulb-PLP group, whereas levator activity changed in relation to oral air pressure change for all subjects in the PLP group. However, levator activity changed in relation to oral air pressure with either speech appliance in place for all subjects irrespective of their speech appliance types.

CONCLUSION

The severity of velopharyngeal incompetence might be related in part to change in levator activity in association with oral air pressure. The effect of a speech appliance to correct velopharyngeal incompetence might consist not only of mechanical obturation of the velopharynx but also of alteration of velopharyngeal function to become similar to normal speakers. Moreover, it is likely that the velopharyngeal system could be well regulated so as to exhibit a consistent outcome of velopharyngeal function.

Effect of environmental pollutants on the production of pro-inflammatory cytokines by normal human dermal keratinocytes

The effect of the environmental pollutants, diesel exhaust particles (DEP) and formaldehyde (FA), on the production of pro-inflammatory cytokines (interleukin (IL)-1alpha, IL-1beta, tumor necrosis factor (TNF)-alpha and IL-8) by normal human dermal keratinocytes (hKCs) was investigated. Normal hKCs were incubated with various concentrations of DEP (0.4, 0.8, 4, or 20 microg/ml) or FA (0.25, 0.5, 1, or 5 microg/ml), and cytokine production was then determined by enzyme-linked immunosorbent assay (ELISA). DEP (20 microg/ml) induced IL-1beta production without altering cell growth. The increased production of IL-1beta induced by this concentration of DEP was further enhanced by the presence of phorbol 12-myristate 13-acetate (PMA), although PMA alone did not affect the levels of IL-1beta. IL-8 production was also increased by DEP (0.4 and 0.8 microg/ml), which is consistent with the results that these concentrations of DEP increased the number of cells significantly after 72 h incubation. Although FA alone did not stimulate the production of IL-1beta or IL-8 by keratinocytes, FA (0.5 microg/ml and 5 microg/ml) significantly increased IL-8 and IL-1beta production, respectively, in cells stimulated with PMA. IL-1alpha production was not modulated by FA or DEP even in the presence of PMA. TNF-alpha was produced by unstimulated keratinocytes at barely detectable levels after 48 h incubation. Although basal levels of TNF-alpha in the culture supernatants were increased after stimulation with PMA, neither pollutant alone nor combination with PMA affected the levels of TNF-alpha. These in vitro findings suggest that environmental pollutants may act as modulating factors of cutaneous inflammation by affecting the ability of keratinocytes to release pro-inflammatory cytokines.

Involvement of focal adhesion kinase in inhibition of motility of human breast cancer cells by sphingosine 1-phosphate

Sphingosine 1-phosphate (SPP), a bioactive sphingolipid metabolite, inhibits chemoinvasiveness of the aggressive, estrogen-independent MDA-MB-231 human breast cancer cell line. As in many other cell types, SPP stimulated proliferation of MDA-MB-231 cells, albeit to a lesser extent. Treatment of MDA-MB-231 cells with SPP had no significant effect on their adhesiveness to Matrigel, and only high concentrations of SPP partially inhibited matrix metalloproteinase-2 activation induced by Con A. However, SPP at a concentration that strongly inhibited invasiveness also markedly reduced chemotactic motility. To investigate the molecular mechanisms by which SPP interferes with cell motility, we examined tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin, which are important for organization of focal adhesions and cell motility. SPP rapidly increased tyrosine phosphorylation of FAK and paxillin and of the paxillin-associated protein Crk. Overexpression of FAK and kinase-defective FAK in MDA-MB-231 cells resulted in a slight increase in motility without affecting the inhibitory effect of SPP, whereas expression of FAK with a mutation of the major autophosphorylation site (F397) abolished the inhibitory effect of SPP on cell motility. In contrast, the phosphoinositide 3'-kinase inhibitor, wortmannin, inhibited chemotactic motility in both vector and FAK-F397-transfected cells. Our results suggest that autophosphorylation of FAK on Y397 may play an important role in SPP signaling leading to decreased cell motility.

Antibody against ganglioside GD1c containing NeuGcalpha2-8NeuGc cooperates with CD3 and CD4 in rat T cell activation

Gangliosides have long been implicated in T cell activation. GD1c with two N-glycolylneuraminic acids [GD1c(NeuGc,NeuGc)] is the predominant ganglioside in rat T cells. In the present study, the anti-GD1c(NeuGc,NeuGc) mAb, AC1, which binds to the NeuGcalpha2-8NeuGcalpha2- sequence, was found to enhance Con A-activated cellular proliferation at a concentration at which AC1 alone did not activate the cells. The potentiation by AC1 was observed more consistently and effectively in the cellular activation elicited by cross-linking of anti-CD3 and anti-CD4, rather than in the cell growth induced by immobilized anti-CD3 alone. Moreover, the combination of immobilized anti-CD4 and soluble AC1 had a remarkable mitogenic effect. In addition, we have demonstrated the existence of a 100 kDa protein in rat T cell lysates which reacts with AC1 on Western blots, and this interaction is abolished by sialidase-treatment of the membrane. Pronase treatment of the T cells, which rendered the 100 kDa protein undetectable on Western-blotting, reduced the number of AC1-positive cells by 40-50% on flow cytometry. On the other hand, all cells became AC1-negative after sialidase treatment. These findings indicated that AC1 reacts with both GD1c(NeuGc,NeuGc) and the 100 kDa glycoprotein on rat T cells. Taken together, these results predict the presence of a novel regulatory mechanism of T cell activation involving CD4 and the NeuGcalpha2-8NeuGcalpha2- sequence.

Renal involvement in Henoch-Schönlein purpura: a multivariate analysis of prognostic factors

This study is the first report in which the relationship between the progression of renal involvement in Henoch-Schönlein purpura (HSP) and various factors was evaluated using a multivariate analysis. Sixty-five (33.5%) of 194 patients with HSP developed renal involvement from three days to 17 months after the onset of the disease. The plasma coagulation factor XIII (F XIII) activity of 97 patients was examined, and 51 (54.3%) of them showed a decreased activity. A univariate analysis showed that an age at the onset of more than seven years, persistent purpura and a decreased F XIII activity all increased the risk of developing renal involvement. A Cox regression model analysis indicated severe abdominal symptoms, persistent purpura and decreased F XIII activity to be significant risk factors and their hazard ratios were 3.26, 11.53 and 2.27, respectively. Corticosteroid treatment had a hazard ratio of 0.36 and was considered to decrease the risk of developing renal involvement. Based on these findings, patients who have the risk factors for renal involvement should be treated with corticosteroids at the onset of the disease to prevent developing renal involvement.

Glycosphingolipid composition of MDA-MB-231 and MCF-7 human breast cancer cell lines

Much evidence has shown that glycosphingolipids are involved in cellular recognition, regulation of cell growth, and metastasis. In the present study, the major glycosphingolipids of two widely studied human breast cancer cell lines were examined. The MCF-7 cell line has functional estrogen and EGF receptors, is dependent on estrogen and EGF for growth, and is uninvasive, while MDA-MB-231 cells are a model for more aggressive, hormone-independent breast cancer. There was twice as much neutral glycolipid in MCF-7 cells as in MDA-MB-231 cells. The major neutral glycolipids in MDA-MB-231 cells were identified as CTH and globoside. MCF-7 cells also contained as the major neutral glycolipids CTH as well as globoside and two other glycolipids which were tentatively identified as galactosylgloboside and fucosylgalactosylgloboside by exoglycosidase treatments. Conversely, the ganglioside content was four fold higher in MDA-MB-231 cells compared to MCF-7 cells. The abundant gangliosides in both cell lines were GM3, GM2, GM1, and GD1a. A minor monosialoganglioside was detected in MDA-MB-231 cells. The striking 18 fold greater amount of GM3 in MDA-MB-231 cells may have important implications because GM3 has been suggested to be involved in regulation of growth factor functions. In agreement, insertion of ganglioside GM3 into the plasma membrane of MCF-7 cells blocked the growth stimulatory effect of EGF.

Gangliosides involved in activation of rat T lineage cells

Gangliosides have long been known to be involved in T-cell activation. In our previous studies, a unique GMlb-derived ganglioside, GD1c(NeuGc,NeuGc), was shown to be the predominant ganglioside in rat thymocytes and T-cells. Upon the activation of the thymocytes, the amount of GD1c(NeuGc,NeuGc) increases remarkably, and additionally a novel species of GD1b, GD1b(NeuGc,NeuGc), appears as the other major ganglioside (Nohara, et al. (1993) J. Biol. Chem. 268, 24997-25000). In the present study, monoclonal antibodies (MAbs) against these two gangliosides have been generated. The MAb AC1 established by immunizing mice with purified GD1c(NeuGc,NeuGc) reacted strongly with GD1c(NeuGc,NeuGc) and weakly with GD1b(NeuGc,NeuGc) by enzyme-linked immunosorbent assay (ELISA). The other MAb AB1 obtained by immunization with GD1b(NeuGc,NeuGc) showed a strong binding activity to GD1b(NeuGc,NeuGc) and no reactivity to GDlc(NeuGc,NeuGc) by ELISA. Flow cytometry analyses using these MAbs have revealed that an AC1-positive subset exists in a portion of resting CD4+CD8- thymocytes and CD4+ splenic T-cells. When the thymocytes were activated with 12-O-tetradecanoylpholbol-13-acetate (TPA) and calcium ionophore A23187, the proportion of AC1+ cells increased remarkably and were detected not only in CD4+ cells but also in CD8+ cells. An increase in the proportion of AC1+ cells was also seen in activated T-cells. In contrast, AB1-positive cells were only detected in activated thymocytes, not in resting thymocytes, or resting or activated T-cells. These results implicate GD1c(NeuGc,NeuGc) in the activation of thymocytes as well as T-cells, whereas GD1b(NeuGc,NeuGc) appears to be specifically related to the activation of thymocytes.

Transcapillary ultrafiltration and peritoneal equilibration test in pediatric patients

The usefulness of the peritoneal equilibration test (PET) in children is unknown. The relationship between transcapillary ultrafiltration and PET was investigated in order to evaluate the usefulness of PET in children. PET was performed on 14 patients undergoing peritoneal dialysis. Their age and bodyweight ranged from 3.8 to 23.6 years and 10.2 to 55.8 kg, respectively. The patients were divided into two groups according to bodyweight; group A patients weighed < or = 40 kg (n = 7) and group B patients weighed > 40 kg (n = 7). There was no significant difference in the mean infusion volume per bodyweight between the two groups, but the mean infusion volume per body surface area was smaller in group A than in group B. Group A showed a more rapid equilibration of dialysate glucose and creatinine than group B. Higher normalized mass transfer area coefficients were evident in group A. In spite of the lower effective glucose gradient in group A, the transcapillary ultrafiltration capacity (TUFC) showed no difference between the two groups. When the slope indices of the regression equations between the two groups were compared, the slopes of the regression in the relationship between TUFC and dialysate (D) ratios D/Do glucose or D/P creatinine in group A were steeper than those in group B. Results of the present study indicate that the larger peritoneal area to infusion volume in patients with smaller body size results in both a rapid equilibration of solutes and sufficient transcapillary ultrafiltration.

Ganglioside GM3 inhibits interleukin-3-dependent bone marrow-derived mast cell proliferation

To investigate the modulated proliferation of an interleukin-3(IL-3)-dependent cell by exogenous ganglioside GM3, mouse bone marrow-derived mast cells (BMMC) were cultured with various concentrations of GM3 in the presence of IL-3. By 4 weeks of culture, most of the nonadherent cells were alcian blue-positive mast cells. Culturing 2-week-cultured BMMC with GM3 for 1 week reduced the number of alcian blue-positive cells, but the increased total histamine content of BMMC was observed. To examine the effect of GM3 on the synergistic response by IL-3 and interleukin-4 (IL-4), 3-week-cultured BMMC were cultured with GM3 in the presence of IL-3 and IL-4 for 1 week. Although the addition of IL-4 to culture medium increased the number of BMMC, treatment with GM3 reduced its proliferative activity. Concerning the effect of GM3 on cell membrane, there are no changes in the expression of IgE receptors on BMMC treated with GM3 though a low concentration of GM3 increased it. However, the production of tumor necrosis factor-alpha from BMMC treated with GM3 was significantly suppressed. These results indicate that in vitro treatment with exogenous GM3 inhibited the proliferative response of IL-3-dependent mast cell populations and modulated its characteristics.

Glycosphingolipids of rat T cells. Predominance of asialo-GM1 and GD1c

Glycosphingolipids play an important role in the immune response, yet their compositions in T and B cells which mediate cellular and humoral immunity, respectively, have not been elucidated. In this study, characteristic features of glycosphingolipids in rat T lineage cells were revealed by comparing the gangliosides and neutral glycolipids of spleen T- and beta-cell-enriched fractions and thymocytes. In T cells, GD1c(NeuGc,NeuGc), a unique ganglioside synthesized through asialo-GM1 (GA1), was the predominant ganglioside as previously found in thymocytes [Nohara, K., Suzuki, M., Inagaki, F., & Kaya, K. (1991) J. Biochem. (Tokyo) 110, 274-278], and the amount was much higher than in thymocytes. In addition, three other GA1-derived gangliosides were detected in T cells and identified as GM1b(NeuAc), GM1b(NeuGc), and GD1 alpha(NeuAc,NeuAc). In contrast, GD1 alpha(NeuAc,NeuAc) was not discernible in thymocytes, although gangliosides corresponding to GM1b(NeuAc) and GM1b(NeuGc) were detected. The neutral glycolipids of T cells contained almost exclusively GA1, while thymocytes contained much lower amounts. The predominance of these GA1-derived gangliosides was confirmed as a singular feature of T lineage cells by comparison with gangliosides of spleen B-cell-enriched fractions which mainly consisted of gangliosides synthesized through GM3 and GM1. Furthermore, the unique structures, which contain the GM1 core and the extended modification of the lacto series, alpha Gal-LacNAc-GM1, alpha Gal-(LacNAc)2-GM1, and sialyl-LacNAc-GM1, were found in B-cell-enriched fractions. Unexpectedly, the neutral glycolipid composition of the thymocytes resembled that of the B-cell enriched fraction rather than that of the T cells.

An activation-associated ganglioside in rat thymocytes

During the activation of rat thymocytes elicited by stimulation with 12-O-tetradecanoylphorbol-13-acetate (TPA) and calcium ionophore A23187, the total amount of gangliosides per cell was demonstrated to increase, reaching a maximum level several times higher than that of resting cells at 48 h after activation when measured at 24-h intervals. The amount of the overwhelmingly predominant ganglioside in resting thymocytes, GD1c (NeuGc,NeuGc) (Nohara, K., Suzuki, M., Inagaki, F., and Kaya, K. (1991) J. Biochem. (Tokyo) 110, 274-278), was found to increase further as a result of activation. Furthermore, another ganglioside, which was barely recognizable in resting thymocytes, was found to increase in activated and proliferating thymocytes to a level similar to that of GD1c. This activation-associated ganglioside was isolated and its structure examined. On the basis of the results of compositional analysis, methylation analysis, sialidase hydrolysis followed by detection with cholera toxin B subunit on TLC, and proton NMR spectroscopy, this ganglioside was clarified to be a rare species of GD1b containing two N-glycolylneuraminic acid residues. On the other hand, when the thymocytes were activated using concanavalin A (ConA) as a stimulant, the amount of gangliosides per cell was increased more strikingly than that in thymocytes activated with TPA and A23187. In the ConA-activated thymocytes, many other gangliosides, in addition to GD1c and GD1b-(NeuGc,NeuGc), were demonstrated to appear in large amounts. The cause of this difference in gangliosides between thymocytes activated with a combination of TPA and A23187 and those activated with ConA is also discussed.

A novel disialoganglioside in rat spleen lymphocytes

A novel ganglioside has been identified as the predominant disialoganglioside of the lymphocytes prepared from rat spleen. The ganglioside was isolated from rat spleen and characterized by compositional analysis, methylation analysis, sialidase hydrolysis, proton NMR spectroscopy, and negative ion fast atom bombardment mass spectrometry. The structure was determined as follows. [formula: see text] This ganglioside is a unique derivative of N-acetyllactosaminyl-GM1. The three monosialogangliosides containing N-acetyllactosaminyl-GM1 structure, which had been originally isolated from rat spleen (Nohara, K., Suzuki, M., Inagaki, F., Ito, H., and Kaya, K. (1990) J. Biol. Chem. 265, 14335-14339), were also found in the lymphocytes and were hardly detected in the spleen remnant tissue depleted of single cells. On the other hand, GD1c(NeuGc,NeuGc) (IV3(NeuGc alpha 2-8NeuGc)-Gg4Cer), the overwhelmingly predominant ganglioside of rat thymocytes (Nohara, K., Suzuki, M., Inagaki, F., and Kaya, K. (1991) J. Biochem. (Tokyo) 110, 274-278), was demonstrated to be only a minor component of the gangliosides of the spleen lymphocytes. These results suggested that GD1c is characteristic for the immature T lineage lymphoid cells and the gangliosides having lactosaminyl-GM1 structure are specific for other populations of the lymphocytes in rat.

Purification and characterization of secretory proteinase of Candida albicans

Proteolytic activity of medically important yeasts was tested in both YCB-BSA agar and medium. All of 134 strains of Candida albicans, 13 of 18 strains of Candida tropicalis and 11 of 18 strains of Candida parapsilosis had this activity, while none of 52 Candida glabrata strains or of 11 Cryptococcus neoformans strains tested had proteolytic activity. Strains of C. albicans fell into five groups based on the level and time-course of in vitro proteinase productivity. Five strains randomly selected from each group were tested for pathogenicity in mice. The strain possessing the strongest pathogenicity was used to purify proteinase. The molecular weight of the proteinase was approximately 44,000 daltons and its isoelectric point was pH 4.2. Optimal pH of the proteinase was 3.2 and the enzyme was stable below pH 7.0 and lost its activity above pH 8.0 at 37 C in a 60-min incubation. The 23 amino acid sequence of the proteinase N-terminus was determined.

A GM1b-derived disialoganglioside GD1c is the predominant ganglioside of rat thymocytes

The thin-layer chromatographic (TLC) pattern of gangliosides of rat thymocytes showed a profile characterized by the occurrence of a predominant ganglioside which did not correspond to any reference gangliosides of rat brain. The ganglioside was isolated from rat thymus, and characterized by compositional analysis, methylation analysis, sialidase treatment, negative-ion fast atom bombardment (FAB) mass spectrometry, and proton NMR spectroscopy. The structure was elucidated to be NeuGc alpha 2-8NeuGc alpha 2-3Gal beta 1-3GalNac beta 1-4Gal beta 1-4Glc beta 1-1Cer. This is the major ganglioside of rat thymus lymphoid cells and is one of the GM1b-derived gangliosides, GD1c, having two N-glycolylneuraminic acids. This is the first report on the occurrence of GD1c in normal animal cells.

A unique fucoganglioside with blood group B determinant in rat spleen

A unique fucoganglioside was isolated from rat spleen and characterized by compositional analysis, methylation analysis, exoglycosidase treatment, negative ion fast atom bombardment (FAB) mass spectrometry, and proton NMR spectrometry. The ganglioside was identified as alpha Gal,Fuc-GM1(NeuGc), which has the blood group B determinant at the nonreducing termini, as shown below: (formula; see text) This is the first report describing the occurrence in nature of alpha Gal,Fuc-GM1 containing N-glycolylneuraminic acid.

Identification of novel gangliosides containing lactosaminyl-GM1 structure from rat spleen

Two novel monosialogangliosides were isolated from rat spleen. The structures of the gangliosides (shown below, where NeuNGc is N-glycolylneuraminic acid) were characterized by compositional analysis, methylation analysis, hydrolyses with exoglycosidases, direct probe fast atom bombardment mass spectrometry, and proton nuclear magnetic resonance spectrometry. A novel structure common to both gangliosides was N-acetyllactosaminyl-GM1 LacN-GM1; where GM1 is II3NeuAc-GgOse4Cer), and this is the first paper to report the occurrence of a new group of gangliosides. [formula: see text] Furthermore, in a monosialoganglioside fraction of rat spleen, the occurrence of a ganglioside having two lactosamine units (Gal alpha 1-3(Gal beta 1-4GlcNAc beta 1-3)2-GM1(NeuAc) (alpha Gal-(LacN)2-GM1] was suggested. These gangliosides have a unique structure, which includes the ganglio series ganglioside core and the extended modification characteristic of the lacto series.

2-(7,13-Dihydroxy-2-trans-octadecenoylamino)ethanesulfonic acid (lipotaurine) as an intermediate of taurolipids biosynthesis

A hydroxy fatty-acid-combined taurine (lipotaurine) was found in the taurolipids fraction of Tetrahymena thermophila. Lipotaurine accounted for about 1.4% of the total taurolipids of the cells, and was composed of taurine and 7,13-dihydroxy-2-trans-octadecenoic acid. By nuclear magnetic resonance, mass and infrared spectrometries, the chemical structure of lipotaurine was identified as 2-(7,13-dihydroxy-2-trans-octadecenoylamino)ethanesulfonic acid. When cells of T. thermophila were incubated with the double-labeled lipotaurine which was biosynthesized from [2(n)-3H]taurine and [1-14C]stearic acid, both the radioactivities were detected in taurolipid A, B and C. Furthermore, the ratio of the radioactivities of 3H and 14C in the lysotaurolipids were the same as that of the lipotaurine. From these results, it is suggested that lipotaurine is an intermediate of taurolipid biosynthesis.

Effect of di-n-octyl phthalate on fatty acid composition of phosphatidylcholine in Tetrahymena

We examined the effect of di-n-octyl phthalate (DOP) on fatty acid composition of phosphatidylcholine (PC) in Tetrahymena pyriformis NT-1. When Tetrahymena cells were grown in DOP-containing proteose peptone medium, the cell growth was repressed. This repression was attended by decreases in the PC content of the cells and decreases in oleic (18:1), linoleic (18:2) and linolenic (18:3) acids of PC and an increase in palmitoleic acid (16:1). The ratio of 18:1/stearic acid (18:0) of PC in cells grown in DOP-containing medium was lower than that of control cells, while the ratio of 16:1/palmitic acid (16:0) was higher than that of control. On the other hand, no changes in the ratios of 18:2/18:1 and 18:3/18:2 were observed. The activity of microsomal stearoyl-CoA desaturase from cells grown with DOP (0.63 mumol/ml medium) decreased to 27% of that from control cells, while the microsomal palmitoyl-CoA desaturase activity increased to 210% of the control value. By the addition of dioleoyl glyceride to the DOP-containing medium, the effects of DOP on Tetrahymena cells were completely blocked. These results suggest that the changes in fatty acid composition of PC may be due to the alteration of the substrate specificity of microsomal delta 9-desaturase, and the decrease in stearoyl-CoA desaturase activity may be a cause for the cell growth repression.

The role of the low-molecular weight (less than or equal to 15,000 daltons) apoproteins of pulmonary surfactant

An artificial surfactant was prepared by combining synthetic dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylglycerol and the low-molecular weight (less than or equal to 15,000 daltons) surfactant apoproteins in the proportions 80:20:5. In the Wilhelmy balance, this surfactant formed a film with an equilibrium surface tension of 29 mN/m; surface tension was reduced to nearly zero during cyclic film compression, with effective respreadability during multiple compression-expansion cycles; similar surface properties were recorded with a pulsating bubble. When instilled into the airways of artificially ventilated immature newborn rabbits, the apoprotein-based artificial surfactant produced a five-fold increase in tidal volumes at insufflation pressure 25 cm H2O; this effect is similar to that obtained in previous experiments with natural surfactant phospholipids, administered in equal concentration (5 mg/ml). Higher concentration of the apoprotein-based surfactant could not be evaluated in vivo due to the high viscosity of the material. Systematic studies should be undertaken to find out whether an even more effective artificial surfactant could be prepared from the low-molecular weight apoproteins and other combinations of synthetic phospholipids.

Correlations between physical and physiological properties of various preparations of lung surfactant

The physical and physiological properties of natural surfactant were investigated after the addition of various synthetic lipids. Three types of surfactant were studied: 1. Bovine surfactant with rapid spreading (1.6 s) and a relatively high minimal surface tension during surface compression (16 mN/m). 2. The same surfactant enriched with dipalmitoylphosphatidylcholine (DPPC), tripalmitin, and palmitic acid showing slow spreading (55 s) and low minimal surface tension (5 mN/m). 3. The same surfactant enriched with DPPC and dipalmitin, showing rapid spreading (1.8 s) and low minimal surface tension (6 mN/m). The physiological properties of these surfactants were evaluated in immature newborn rabbits. All three preparations effectively improved lung expansion and stability in pressure-volume recordings, increased tidal volumes during artificial ventilation, and enhanced alveolar volume density in histological sections. The magnitude of the therapeutic effects was similar for non-enriched and enriched materials. Thus, wide variations in in vitro surface properties do not seem to influence the in vivo activity of the surfactant preparations.