Cross-sectional study of the factors associated with the number of teeth in middle-aged and older persons with intellectual disabilities.

BACKGROUND: We investigated the number of teeth in middle-aged and older individuals with intellectual disability and evaluated the related factors. METHODS: A questionnaire survey on oral health was administered to 604 persons over 40 years old with intellectual disabilities in Aichi Prefecture, Japan. The questionnaire designed for this study included items on diagnosis of disability, severity of intellectual disability and type of residence. As oral-health-related factors, the proxy-reported number of teeth, family dentist, regular dental check-ups, problems during dental treatment and tooth-brushing frequency were evaluated. A multinomial logistic regression analysis was performed using the proxy-reported number of teeth (≥20, 10-19 or 0-9) as the dependent variable, and the odds ratios (ORs) and 95% confidence intervals (CIs) of independent variables were calculated. In addition, linear regression analysis was performed using the proxy-reported number of teeth as the dependent variable. RESULTS: In the multivariate multinomial logistic regression analysis, age, diagnosis of disability and type of residence were significantly associated with having 10-19 versus ≥20 teeth. Participants with autism spectrum disorder had a significantly lower OR for 10-19 teeth compared with those with intellectual disability [OR (95% CI): 0.49 (0.22-1.08)]. Age, diagnosis of disability, regular dental check-ups and tooth-brushing frequency were significantly associated with having 0-9 versus ≥20teeth. Participants with Down syndrome had a significantly higher OR for 0-9 teeth compared with those with intellectual disability [OR (95% CI): 3.17 (1.09-9.23)]. The ORs for 0-9 teeth of participants who did not attend regular dental check-ups and who brushed their teeth 1 time/day compared with ≥3 times/day were significantly high, and the OR (95% CI) was 2.37 (1.06-5.30) and 4.76 (1.09-20.77), respectively. [Corrections made on 22 August 2022, after first online publication: in the previous sentence, "who attend" has been changed to "who did not attend".] In the multivariate linear regression analysis, age, diagnosis of disability and regular dental check-ups were significantly associated with the proxy-reported number of teeth. The proxy-reported number of teeth was -0.42 less with each 1-year increase in age. With autism spectrum disorder, the proxy-reported number of teeth was 0.74 more compared with intellectual disability. In Down syndrome, the proxy-reported number of teeth was -0.93 less compared with intellectual disability. The proxy-reported number of teeth was -2.12 less for those who did not have regular dental check-ups. CONCLUSIONS: The number of teeth in middle-aged and older individuals with intellectual disability was related to age and the type of disability. Regular dental visits may be effective at preventing tooth loss in middle-aged and older persons with intellectual disability.

Utility of the Berlin Initiative Study-1 equation for the prediction of serum vancomycin concentration in elderly patients aged 75 years and older.

Accurate assessment of renal function is essential for determining serum vancomycin (VCM) concentration. Creatinine clearance (Ccr)-calculated using the Cockcroft and Gault (CG) equation-can be used to evaluate renal function for determining VCM dosage. However, Ccr-based evaluation may not be an accurate representation of the renal function in the elderly. Herein, we examine the effectiveness of estimated glomerular filtration rate (eGFR) calculated using the Berlin Initiative Study-1 (BIS1) equation, for predicting the serum VCM concentration. Herein, we retrospectively analyzed patients (aged ≥ 75 years) who had received VCM. Serum VCM concentration was predicted based on Ccr and eGFR. eGFR was calculated using the Japanese equation for eGFR (eGFRJAP), Modification of Diet in Renal Disease (MDRD) equation (eGFRMDRD), chronic kidney disease epidemiology collaboration (CKD-EPI) equation (eGFRCKD-EPI), and BIS1 equation (eGFRBIS1). The predicted serum VCM concentration was compared with the measured values. Prediction bias, accuracy, and precision were evaluated by calculating the mean prediction error (ME), mean absolute prediction error (MAE), and root mean squared prediction error (RMSE). Our results showed that the ME between the measured and the predicted values calculated using Ccr and each eGFR was the largest and smallest when calculated based on Ccr and eGFRMDRD, respectively. MAE and RMSE were the largest and smallest when calculated based on Ccr and eGFRBIS1, respectively. A significant difference was observed in the MAE associated with eGFRJAP, eGFRMDRD, and eGFRCKD-EPI compared to that associated with eGFRBIS1. In conclusion, our results suggest that the BIS1 equation might be useful for determining the VCM dosage in the elderly.

Interaction-Induced Shubnikov-de Haas Oscillations in Optical Conductivity of Monolayer MoSe_{2}.

We report polarization-resolved resonant reflection spectroscopy of a charge-tunable atomically thin valley semiconductor hosting tightly bound excitons coupled to a dilute system of fully spin- and valley-polarized holes in the presence of a strong magnetic field. We find that exciton-hole interactions manifest themselves in hole-density dependent, Shubnikov-de Haas-like oscillations in the energy and line broadening of the excitonic resonances. These oscillations are evidenced to be precisely correlated with the occupation of Landau levels, thus demonstrating that strong interactions between the excitons and Landau-quantized itinerant carriers enable optical investigation of quantum-Hall physics in transition metal dichalcogenides.

Molecular characterization of fungal populations on the tongue dorsum of institutionalized elderly adults.

OBJECTIVES: To characterize the global composition of oral fungal populations in frail elderly adults and to investigate the relationship with their health status. MATERIALS AND METHODS: We investigated the fungal populations on the tongue dorsum in 291 institutionalized elderly adults by molecular PCR-based techniques using internal transcribed spacer regions of nuclear ribosomal DNA. RESULTS: Quantitative PCR analysis showed that fungi were present on the tongue dorsum of 128 subjects at ≥10(4) CFU per sample, and 35 of them exceeded 10(5) CFU per sample. Length heterogeneity-PCR analysis and nucleotide sequence determinations showed that Candida albicans was most frequently detected in those subjects with fungi at ≥10(4) CFU per sample (105 subjects), followed by Candida dubliniensis (78), Malassezia restricta (57), and Candida tropicalis (45). Statistical analysis revealed that those subjects with ≥10(5) CFU of fungi other than C. albicans per sample had an increased risk of fever (≥7 febrile days per 12 months) compared with subjects with <10(5) CFU per sample, after adjustment for other fever-associated confounding factors. CONCLUSIONS: These data demonstrate that the oral cavity of the elderly is inhabited by a diverse array of fungi not limited to typical Candida species and they suggest that the diversity in distribution is associated with health status.

[How to protect the surgeons' faces against spurting blood from the ascending aorta].

The blood spurting from the ascending aorta is uncomfortable for cardiac surgeons. To protect the surgeons' faces from this spurting blood, we use a longitudinal half of a plastic bottle, which is semi see-through. While the assistant is holding this device above the ascending aorta, the surgeons can proceed the operation with good surgical view.

[One stage repair for extensive aortic aneurysm using the pull-through technique].

We describe 2 cases of extensive aortic aneurysm. One was an 88-year-old female with a diagnosis of a rupture of the distal descending aortic aneurysm and the distal arch aneurysm. The 2nd case was a 68-year-old female who had undergone graft replacement of the ascending aorta for acute type A dissection 5 years before. She was diagnosed with an enlarging aneurysm of the false lumen from the transverse arch to the distal descending aorta. We performed 1 stage replacement of the aortic arch and the descending thoracic aorta by using the pull-through technique with a long elephant trunk (LET) through a median sternotomy under selective cerebral perfusion. Distal anastomosis of LET was done by posterior mediastinal approach. Postoperative courses were uneventful without neurological deterioration or respiratory distress.

Periodontitis Is Associated with Chronic Obstructive Pulmonary Disease.

Although they are known to share pathophysiological processes, the relationship between periodontitis and chronic obstructive pulmonary disease (COPD) is not fully understood. The aim of the present study was to test the hypothesis that periodontitis is associated with a greater risk of development of COPD, when smoking is taken into account. The analysis in a 5-y follow-up population-based cohort study was based on 900 community-dwelling Japanese adults (age: 68.8 ± 6.3 [mean ± SD], 46.0% male) without COPD aged 60 or older with at least 1 tooth. Participants were classified into 3 categories according to baseline periodontitis severity (no/mild, moderate, and severe). COPD was spirometrically determined by a fixed ratio of <0.7 for forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and by FEV1/FVC below the lower limit of normal. Poisson regression was used to calculate the relative risk (RR) of developing COPD according to the severity of periodontitis. The population attributable fraction (PAF) was also calculated. During follow-up, 22 (2.4%) subjects developed COPD. Compared with no/mild periodontitis subjects, a significantly increased risk of COPD occurred among severe periodontitis subjects (RR = 3.55; 95% confidence interval [CI], 1.18 to 10.67), but no significant differences were observed between the no/mild and moderate categories (RR = 1.48; 95% CI, 0.56 to 3.90). After adjustment for potential confounders, including smoking intensity, the relationship between severe periodontitis and risk of COPD remained significant (RR = 3.51; 95% CI, 1.15 to 10.74). Likewise, there was a positive association of periodontitis severity with risk of COPD ( P for trend = 0.043). The PAF for COPD due to periodontitis was 22.6%. These data highlight the potential importance of periodontitis as a risk factor for COPD.

Serum levels of resistin and adiponectin in women with periodontitis: the Hisayama study.

Resistin and adiponectin, recently discovered adipokines, are secreted from adipose tissue, with postulated opposing functions in insulin resistance and inflammation. More recently, an abundance of resistin was detected in macrophages, which suggests its important role in inflammation. The aim of this study was to clarify circulating serum adipokine levels in women with periodontitis. Thirty-four women with moderate to severe periodontitis and 42 control individuals with healthy gingiva (50- to 59-year-old women) were selected. The serum level of adipokines was analyzed between groups, along with the obesity index, smoking status, and age. Having periodontitis was significantly associated with an increased level of resistin, both in bivariate (OR, 3.0; 95% CI, 1.2-7.6) and multivariate (adjusted OR, 3.1; 95% CI, 1.1-8.6) analyses. The association of periodontitis with a decreased level of adiponectin did not reach statistical significance. It was concluded that an increased serum resistin level in middle-aged Japanese women with periodontitis may affect systemic health.

Relationship of metabolic syndrome to periodontal disease in Japanese women: the Hisayama Study.

Recent studies have suggested that several systemic conditions--such as obesity, hypertension, hyperlipidemia, and diabetes--are related to periodontitis. The objective of this study was to examine the relationship between periodontitis and 5 components of metabolic syndrome--abdominal obesity, triglyceride level, high-density lipoprotein cholesterol level, blood pressure, and fasting blood sugar level--in 584 Japanese women. In multivariate analyses, persons exhibiting more components of metabolic syndrome had significantly higher odds ratios for a greater pocket depth and clinical attachment loss than did those with no components; the odds ratios for a greater pocket depth and clinical attachment loss of the persons exhibiting 4 or 5 components were 6.6 (95% confidence interval = 2.6-16.4) and 4.2 (95% confidence interval = 1.2-14.8), respectively. These results indicate that metabolic syndrome increases risk of periodontitis, and suggest that people exhibiting several components of metabolic syndrome should be encouraged to undergo a periodontal examination.

The extent of alveolar bone loss is associated with impaired glucose tolerance in Japanese men.

BACKGROUND: The treatment of periodontal disease in diabetic patients is reported to have a beneficial effect on their glucose control. A recent study indicated that having deep pockets is significantly associated with past development of glucose intolerance in non-diabetic individuals using an oral glucose tolerance test (OGTT). These findings suggest that periodontal disease is a risk factor for diabetes, although more evidence is needed. METHODS: A total of 193 Japanese men aged 50 to 54 years with at least 10 teeth were examined as part of a comprehensive health examination before retirement from the Japan Self-Defense Force. Alveolar bone loss of the posterior teeth was measured on a panoramic x-ray film. An OGTT was administered and impaired glucose tolerance (IGT) and diabetes were defined. The relationships between the mean ratio of alveolar bone loss to root length and OGTT results were analyzed after adjusting for known risk factors for diabetes. RESULTS: The proportion of subjects with IGT increased significantly in the subjects with higher tertiles of alveolar bone loss (P<0.05). In the multivariate logistic regression analysis excluding diabetic subjects, the adjusted OR for IGT to normal glucose tolerance (NGT) increased in subjects with higher tertiles of alveolar bone loss (P for trend=0.03). In the subjects with the highest tertile of alveolar bone loss, the adjusted OR for IGT to NGT was 4.27 (95% confidence interval [CI]: 1.41 to 12.9; P=0.01). CONCLUSION: The degree of alveolar bone loss is significantly associated with IGT, suggesting that periodontitis with alveolar bone loss is associated with impaired glucose tolerance.

High Efficiency CVD Graphene-lead (Pb) Cooper Pair Splitter.

Generation and manipulation of quantum entangled electrons is an important concept in quantum mechanics, and necessary for advances in quantum information processing; but not yet established in solid state systems. A promising device is a superconductor-two quantum dots Cooper pair splitter. Early nanowire based devices, while efficient, are limited in scalability and further electron manipulation. We demonstrate an optimized, high efficiency, CVD grown graphene-based Cooper pair splitter. Our device is designed to induce superconductivity in graphene via the proximity effect, resulting in both a large superconducting gap Δ = 0.5 meV, and coherence length ξ = 200 nm. The flat nature of the device lowers parasitic capacitance, increasing charging energy EC. Our design also eases geometric restrictions and minimizes output channel separation. As a result we measure a visibility of up to 86% and a splitting efficiency of up to 62%. This will pave the way towards near unity efficiencies, long distance splitting, and post-splitting electron manipulation.

Assessment of the intrapulmonary ventilation-perfusion distribution after the Fontan procedure for complex cardiac anomalies: relation to pulmonary hemodynamics.

In 12 patients who underwent the Fontan procedure for complex cardiac anomalies, lung scanning with xenon-133 was performed to assess the intrapulmonary ventilation-perfusion distribution, and comparison was made with a control group. All data were then analyzed in relation to either pre- or postoperative pulmonary hemodynamic data. In ventilation scans, the intrapulmonary distribution in the right lung was almost normal. In perfusion scans, an abnormal increased upper to lower lobe perfusion ratio greater than the normal value found in the control group was noted in seven patients (58.3%). There was a significant correlation (p less than 0.02) between the upper to lower lobe perfusion ratio and postoperative pulmonary vascular resistance. Furthermore, this perfusion ratio correlated inversely with the preoperative (p less than 0.005) and postoperative (p less than 0.02) right pulmonary artery area index, defined as the ratio of cross-sectional area to the normal value. Of five patients with less than 90% arterial oxygen saturation, four showed an abnormal distribution of pulmonary blood flow greater than the normal perfusion ratio. No patient had evidence of a pulmonary arteriovenous fistula by the echocardiographic contrast study. These results suggest that abnormal distribution of pulmonary blood flow to the upper lung segment may develop in patients after the Fontan procedure, and that insufficient size of the pulmonary artery before operation and the consequent postoperative elevation of pulmonary vascular resistance may be responsible for this perfusion abnormality.

Exogenous 20K growth hormone (GH) suppresses endogenous 22K GH secretion in normal men.

The physiological and pharmacological functions of the 20-kDa human GH (20K-hGH) isoform are unknown. We conducted a pharmacokinetic study of recombinant 20K-hGH in human subjects (Phase I clinical trial). Placebo or 20K-hGH was administered sc to normal men (20-31 yr of age, n = 6-8 per group) at 2100 h. Serum 20K- and 22K-hGH levels were monitored every 30 min for 24 h by specific enzyme-linked immunosorbent assays. Serum free fatty acid, insulin-like growth factor I, insulin, and glucose levels were measured for 24 h. In the placebo group, the secretion profiles of endogenous 20K- and 22K-hGH were pulsatile and similar to each other. The proportion of 20K- to 22K-hGH was fairly constant. In the 20K-hGH-treated groups, serum 20K-hGH levels increased in a dose-dependent manner over the dose range of 0.01-0.1 mg/kg. Maximum serum 20K-hGH levels were reached at 3-4 h and decreased with half-lives of 2-3 h. Marked suppression of endogenous 22K-hGH secretion was observed in a time-dependent manner. Serum free fatty acid and insulin-like growth factor I levels were significantly elevated (P < 0.01) at 4, 8, and 12 h and at 8, 12, and 24 h after 20K-hGH administration, respectively. Serum insulin and glucose levels did not change significantly within 24 h. These results suggested that: 1) regulation of 20K-hGH secretion is physiologically the same as that of 22K-hGH; 2) the pharmacokinetics after sc injection of 20K-hGH are comparable with those of 22K-hGH; 3) 20K-hGH regulates hGH secretion through "GH-induced negative feedback mechanisms"; and 4) administration of 20K-hGH is expected to exert GH actions (growth-promoting activity and lipolytic activity). Monitoring of serum 20K- and 22K-hGH levels may be useful in evaluating the effects of administered GH isoforms on their own release from the pituitary.

Evidence that graft coronary arteriosclerosis begins in the early phase after transplantation and progresses without chronic immunoreaction. Histopathological analysis using a retransplantation model.

The histopathological features of chronic rejection and its initiation were assessed using rat heterotopic heart transplantation and retransplantation models. Fully allogeneic or minor, non-MHC antigen-mismatch heart grafts transplanted into recipient rats treated with a short course of FK506 showed long-term survival but developed graft atherosclerosis after 40 days posttransplantation. Retransplantation of allografts back into the original donor strain did not prevent graft atherosclerosis if the grafts had resided in the primary recipient for up to 5 days; residence in the primary allogeneic recipient for less than 4 days did not result in graft atherosclerosis in the secondary recipient. Short-course administration of FK506 did not affect the production of these changes. Graft coronary arteriosclerosis begins between 3 and 5 days posttransplantation and progresses without continuous allogeneic immunological drive. The present findings will provide a new means by which to approach the analysis of development of chronic allograft rejection.

Fate of right ventricular hypertrophy in tetralogy of Fallot after corrective surgery.

To elucidate the reversibility of right ventricular (RV) myocardial hypertrophy in tetralogy of Fallot (TF), 30 patients underwent RV endomyocardial biopsies 1 to 25 years (mean 9.7 +/- 6.6) after corrective surgery. Myocardial cell diameter was evaluated by comparing histopathologic data with preoperative patients with TF and normal subjects. As a whole, postoperative cell diameter was smaller than that of age-matched preoperative patients with TF, and larger than that of age-matched normal subjects. In 7 patients without significant residual pulmonary stenosis whose preoperative data were also available, cell diameter significantly decreased after surgery (17.1 +/- 2.1 to 14.0 +/- 2.1 microns, p < 0.01). There was a positive correlation between postoperative cell diameter and age at study (p < 0.01). To negate the influence of age, cell diameter was expressed in terms of a percentage of age-matched normal values (percent cell diameter). There was no significant correlation between percent cell diameter and age at surgery, age at study or the follow-up periods. There were positive correlations between percent cell diameter and the following parameters: RV systolic pressure (p < 0.05), percent normal RV end-diastolic (p < 0.05) and end-systolic (p < 0.01) volumes. These results demonstrate that RV myocardial hypertrophy in TF can regress to some extent after corrective surgery if significant residual pulmonary stenosis is avoided.

Relation of impaired left ventricular function in mitral regurgitation to left ventricular contractile state after mitral valve replacement.

To reevaluate the postoperative contractile state and survival, 34 patients (19 men and 15 women; average age 45 years, range 23 to 65) undergoing conventional mitral valve replacement between 1980 and 1990 were studied. There were 5 cardiac deaths (2 early and 3 late). Four of 5 deaths occurred in patients who had a preoperative left ventricular end-systolic volume index > 100 ml/m2. Sixteen patients with an end-systolic volume index < 100 ml/m2 (group I), and 5 with an index > 100 ml/m2 (group II) underwent repeat catheterization 8 months (range 4 to 17) after surgery. The ratio of end-systolic wall stress to end-systolic volume index increased significantly after surgery in group I, whereas it remained reduced in group II. The postoperative end-systolic wall stress/volume index ratio correlated significantly with the preoperative end-systolic volume index (p < 0.001). In the relation between end-systolic wall stress and ejection fraction, all patients in group II had values that were less than the 95% confidence limits for the normal relation. In conclusion, patients with a preoperative end-systolic volume index > 100 ml/m2 appeared to be at high risk of incurring irreversible depressed myocardial contractility, with a high postoperative mortality.

Right ventricular myocardial function after atrial switch operation for transposition of the great arteries.

Postoperative right ventricular (RV) myocardial function was evaluated in 6 patients who underwent atrial switching for simple transposition of the great arteries (TGA). The average age at study was 5.5 years. RV function was evaluated at rest and during administration of methoxamine by cardiac catheterization and RV angiography. The data were compared with left ventricular function in a control group, which consisted of 6 patients, 3 with functional murmur and 3 with pulmonary valvar stenosis. During stress, the TGA group showed a significant increase in end-diastolic pressure, minute work index and end-diastolic and end-systolic volume indexes, along with a significant decrease in ejection fraction. The control group also showed an increase in these variables except for ejection fraction during stress, which did not change. The slope of the work-function curve for the TGA group was lower than that for the control group (p = 0.02). The TGA group had a lower slope of the peak systolic pressure-volume relation than the control group (p = 0.005). There was no significant correlation between the slope of the peak systolic pressure-volume relation and age at repair or study. This study shows that RV pump dysfunction observed in postoperative TGA patients may be caused by depressed myocardial function.

Pulmonary artery morphology and hemodynamics in pulmonic valve atresia with ventricular septal defect before and after repair.

Cardiac catheterization and angiography were performed in 22 patients with pulmonic valve atresia and ventricular septal defect to evaluate pulmonary morphology and hemodynamics before and after repair. In 12 of the 22, pulmonic valve atresia and ventricular septal defect were associated with major aortopulmonary collateral arteries, which were ligated in most. Mean postoperative pulmonary artery pressure (PAP) ranged from 9 to 92 mm Hg (mean 28 +/- 19) and pulmonary vascular resistance ranged from 1.1 to 35.2 U.m2 (mean 6.4 +/- 8.0). These data correlated (r = 0.89, p less than 0.001). The number of pulmonary artery subsegments connected to the central pulmonary arteries was 22 to 42 (mean 38 +/- 6). Univariate analysis revealed that the mean postoperative PAP correlated with the number of pulmonary artery subsegments connected to the central pulmonary arteries (r = -0.81, p less than 0.001), with mean postoperative PAP (r = 0.79, p less than 0.001), with the postoperative pulmonary artery area index of the right and left pulmonary arteries at prebranching (r = -0.76, p less than 0.001), and with the sum of the pulmonary artery areas after branching (r = -0.69, p less than 0.005). Pulmonary vascular resistance correlated with the number of pulmonary artery subsegments connected to the central pulmonary arteries (r = -0.85, p less than 0.001), with the mean preoperative PAP (r = 0.79, p less than 0.001), with the sum of the pulmonary artery areas after branching (r = -0.73, p less than 0.001), and with the postoperative pulmonary artery area index (r = -0.70, p less than 0.001). The incidence of pulmonary vascular resistance being less than 3 U.m2 was significantly higher in patients with greater than 36 pulmonary artery subsegments connected to the central pulmonary arteries and with a preoperative pulmonary artery area index greater than 0.5 (88%) (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Ventricular volume characteristics of single ventricle before corrective surgery.

With use of biplane cineangiocardiograms, ventricular cavity volume measurements were determined in 17 patients with single ventricle, before total correction. There were 4 patients with a single left and 13 with a single right ventricle. Atrioventricular (A-V) valve regurgitation was evident in 6 of 13 patients with a common A-V valve. End-diastolic volume index ranged from 72 to 282 ml/m2 (average 131 ml/m2), and these values ranged from 71 to 206 percent (average 110 percent) of the sum of the normal left and right ventricular end-diastolic volumes. Ejection fraction averaged 0.55. There was no significant difference in ventricular cavity volume characteristics and ventricular function between patients with single and and single right ventricle. The single ventricle ejects blood to both the systemic and the pulmonary circulatory beds. There was a high correlation of end-diastolic volume index with pulmonary to system flow ratio (r = +0.89, p less than 0.001). This observation indicates that the major factor affecting ventricular cavity volume in single ventricle is pulmonary blood flow and a systemic to pulmonary arterial shunt should increase the ventricular cavity volume. Ventricular function of single ventricle was depressed. The ejection fraction of patients with A-V valve regurgitation averaged 0.49, which was significantly lower than that (0.58) of patients without regurgitation (p less than 0.05). A-V valve regurgitation was also a factor that increased ventricular cavity volume, although the ventricular function became more depressed.

Isolation of the third component of complement and its derivative with anaphylatoxin-like activity from the plasma of the newt Cynops pyrrhogaster.

The third component of complement (C3) of a newt, Cynops pyrrhogaster, was purified using a fast protein liquid chromatography technique. The purified newt C3 consists of two polypeptide chains (the molecular masses of the alpha and beta-chains of C3 were 120,000 and 70,000, respectively) linked by disulfide bonds. The alpha-chain retained an internal thiolester bond that was cleaved with methylamine, and the N-terminal amino acid sequence of the alpha-chain was XVQLIDAKAGKAAKF. Digestion of newt C3 with trypsin yielded fragments that induced significant histamine release from newt peritoneal cells. These results indicate that newt C3 retains structural and functional properties shared with mammalian C3.