Cultivable anaerobic microbiota of severe early childhood caries.

Severe early childhood caries (ECC), while strongly associated with Streptococcus mutans using selective detection (culture, PCR), has also been associated with a widely diverse microbiota using molecular cloning approaches. The aim of this study was to evaluate the microbiota of severe ECC using anaerobic culture. The microbial composition of dental plaque from 42 severe ECC children was compared with that of 40 caries-free children. Bacterial samples were cultured anaerobically on blood and acid (pH 5) agars. Isolates were purified, and partial sequences for the 16S rRNA gene were obtained from 5,608 isolates. Sequence-based analysis of the 16S rRNA isolate libraries from blood and acid agars of severe ECC and caries-free children had >90% population coverage, with greater diversity occurring in the blood isolate library. Isolate sequences were compared with taxon sequences in the Human Oral Microbiome Database (HOMD), and 198 HOMD taxa were identified, including 45 previously uncultivated taxa, 29 extended HOMD taxa, and 45 potential novel groups. The major species associated with severe ECC included Streptococcus mutans, Scardovia wiggsiae, Veillonella parvula, Streptococcus cristatus, and Actinomyces gerensceriae. S. wiggsiae was significantly associated with severe ECC children in the presence and absence of S. mutans detection. We conclude that anaerobic culture detected as wide a diversity of species in ECC as that observed using cloning approaches. Culture coupled with 16S rRNA identification identified over 74 isolates for human oral taxa without previously cultivated representatives. The major caries-associated species were S. mutans and S. wiggsiae, the latter of which is a candidate as a newly recognized caries pathogen.

Clonal analysis of the microbiota of severe early childhood caries.

BACKGROUND/AIMS: Severe early childhood caries is a microbial infection that severely compromises the dentition of young children. The aim of this study was to characterize the microbiota of severe early childhood caries. METHODS: Dental plaque samples from 2- to 6-year-old children were analyzed using 16S rRNA gene cloning and sequencing, and by specific PCR amplification for Streptococcus mutans and Bifidobacteriaceae species. RESULTS: Children with severe caries (n = 39) had more dental plaque and gingival inflammation than caries-free children (n = 41). Analysis of phylotypes from operational taxonomic unit analysis of 16S rRNA clonal metalibraries from severe caries and caries-free children indicated that while libraries differed significantly (p < 0.0001), there was increased diversity than detected in this clonal analysis. Using the Human Oral Microbiome Database, 139 different taxa were identified. Within the limits of this study, caries-associated taxa included Granulicatella elegans (p < 0.01) and Veillonella sp. HOT-780 (p < 0.01). The species associated with caries-free children included Capnocytophaga gingivalis (p < 0.01), Abiotrophia defectiva (p < 0.01), Lachnospiraceae sp. HOT-100 (p < 0.05), Streptococcus sanguinis (p < 0.05) and Streptococcus cristatus (p < 0.05). By specific PCR, S. mutans (p < 0.005) and Bifidobacteriaceae spp. (p < 0.0001) were significantly associated with severe caries. CONCLUSION: Clonal analysis of 80 children identified a diverse microbiota that differed between severe caries and caries-free children, but the association of S. mutans with caries was from specific PCR analysis, not from clonal analysis, of samples.

Effect of head-out water immersion on cardiorespiratory response to dynamic exercise.

Head-out water immersion is known to produce several cardiopulmonary adjustments at rest due to a cephalad shift in blood volume. The purpose of this study was to determine the effect of head-out water immersion on the cardiorespiratory response to graded dynamic exercise. Nineteen healthy middle-aged men performed upright cycling exercise at 40, 60 and 80% of maximal oxygen consumption on land and in water (31.0 +/- 1.0 degrees C) to the shoulders. Cardiac output (measured by the carbon dioxide rebreathing technique) was significantly greater in water at 40 and 80% maximal oxygen consumption. Stroke volume was significantly elevated at all stages of exercise. Heart rate did not differ significantly at 40 and 60% maximal oxygen consumption but was significantly lower in water at 80% maximal oxygen consumption. Total ventilation did not differ significantly in water and on land at any stage of exercise. The results suggest that the central redistribution of blood volume with head-out water immersion leads to an increase in stroke volume. Because there is not a proportional decrease in heart rate with the elevated stroke volume, cardiac output is regulated at a higher level during upright exercise in water compared with that on land. In conclusion, there are serious limitations of available, prerecorded rhythm data bases for designing and testing of automatic external defibrillators. Performance can be adequately assessed only by extensive clinical tests, which seem mandatory for this new and important type of defibrillator.

Haemophilus parainfluenzae mitral valve vegetation without hemodynamic abnormality. Demonstration by angiography and serial echocardiography.

The occurrence of Haemophilus parainfluenzae endocarditis on a previously normal mitral valve of a drug addict is described. A large mitral valve vegetation was demonstrated by serial echocardiography and cineangiography. The vegetation did not produce hemodynamic abnormalities preventing detection by physical examination. Multiple septic emboli to various organs, including brain, resulted in death. The role of serial echocardiography and the levophase of right heart cineangiography in detecting mitral valve vegetation in a patient suspected of having infective endocarditis is emphasized.

Effects of once-daily benazepril therapy on exercise tolerance and manifestations of chronic congestive heart failure. The Benazepril Heart Failure Study Group.

The effects of the long-acting angiotensin-converting enzyme inhibitor benazepril hydrochloride on exercise tolerance and signs and symptoms of congestive heart failure (CHF) were evaluated in a double-blind, multicenter, placebo-controlled clinical trial. Patients with chronic New York Heart Association class II to IV symptoms of CHF and an ejection fraction by radionuclide scanning of less than or equal to 35% were randomized in a 2:1 ratio to treatment with ascending doses of oral benazepril (n = 114) or placebo (n = 58) once daily, while continuing to receive background therapy with digoxin and diuretics. After randomization, patients were evaluated clinically every 2 weeks during a 12-week, double-blind treatment period. Maximal exercise tolerance was measured before and at specified time points after randomization by graded treadmill exercise testing. At week 12, mean exercise time increased 95 +/- 12 (SEM) seconds in the group receiving benazepril, whereas the increase was 37 +/- 18 seconds in the group receiving placebo (p less than 0.01 for the difference between the groups). There was also greater improvement in overall clinical status and in the signs and symptoms of CHF in benazepril-treated patients than in control subjects. There were 3 deaths in placebo-treated patients and none in benazepril-treated patients (p less than 0.05); the overall incidence of adverse effects was identical in the 2 groups. Benazepril is a well-tolerated angiotensin-converting enzyme inhibitor that provides clinically important improvement in exercise tolerance and in signs and symptoms when given once daily to patients with CHF receiving background therapy with digoxin and a diuretic.

Effect of aorta-coronary bypass operation on factors precipitating angina.

About two thirds (65 percent) of 271 male patients and one half of the 44 female patients who had angina pectoris prior to the aorta-coronary bypass operation experienced total relief of symptoms 1 year after the operation. This was especially apparent for angina associated with walking activity and the postprandial angina. In the nonoperated patients who had angina pectoris and only mild or no coronary artery obstruction, 38 percent of the 127 men and 27 percent of the 73 women were free of symptoms 1 year after the original examination.

Carotid baroreflex responsiveness in high-fit and sedentary young men.

The influence of fitness on cardiac vagal activity and baroreflex-mediated control of heart rate has not been clearly established in humans. Therefore, we studied resting cardiac vagal activity by evaluating respiratory sinus arrhythmia (RSA) and examined carotid-cardiac baroreflex responsiveness with a neck collar in 11 high-fit and 9 sedentary [based on maximal O2 consumption (VO2max) and history of physical activity] healthy young men (19-31 yr of age). Resting cardiac vagal activity was determined from the standard deviation of 100 consecutive resting R-R intervals. Baroreflex responsiveness was determined from the R-R interval responses to neck suction and pressure (repeated trials of 5-s stimuli of -20, -40, and 35 mmHg). Both RSA and the bradycardic (R-R interval) responses to neck suction of -40 mmHg were significantly greater (P less than 0.05) in the high-fit individuals (RSA, 116.5 +/- 11.5 ms; neck-suction response, 145.3 +/- 17.0 ms; mean +/- SE) compared with sedentary subjects (RSA, 65.2 +/- 6.6 ms; neck-suction response, 86.9 +/- 12.5 ms). Responses of the high-fit volunteers to the other intensities of neck stimuli (-20 and 35 mmHg) showed a similar trend but were not significantly different from those of the sedentary volunteers. The baroreflex slope derived from these data was significantly greater in the high-fit subjects (4.00 +/- 0.39 ms/mmHg) compared with the sedentary controls (2.53 +/- 0.28 ms/mmHg). These data suggest that resting cardiac vagal activity is greater, carotid-to-cardiac activity is well maintained, and baroreflex sensitivity, i.e., slope, is augmented in high-fit subjects.

Effect of head-out water immersion on response to exercise training.

During spaceflight and head-out water immersion (WI) there is a cephalad shift in blood volume. We have recently shown that left ventricular end-diastolic dimension is significantly greater during moderate cycling exercise with WI compared with on land. The purpose of this study was to determine whether the cephalad shift in blood volume and accompanying increase in cardiac preload with WI alters the normal cardiovascular adaptations to aerobic exercise training. Nine middle-aged healthy men trained on cycle ergometers in water, nine trained on land, and four served as controls for 12 wk. Following training, both training groups showed similar increase (P less than 0.05) in stroke volume and similar decreases in heart rate (P less than 0.01) and blood pressure (P less than 0.05) at a given submaximal exercise O2 consumption (VO2). Maximal VO2 increased (P less than 0.01) similarly for both training groups. The control group did not demonstrate any significant changes in submaximal or maximal exercise responses. We conclude that the cephalad shift in blood volume with WI does not alter the normal cardiovascular adaptation to aerobic exercise training.

Scapuloperoneal syndrome. Report on two families with neurogenic muscular atrophy.

Scapuloperoneal syndrome is a more or less clinically distinct neurologic entity with predominant involvement of scapular and peroneal muscles. The disease shows a variable mode of inheritance. Electromyography and muscle biopsy has shown the presence of denervation and dystrophic changes, sometimes both in the same patient. Cardiac manifestations when present add a graver prognosis to an otherwise relatively benign disease. Study of two cases in this report, one with significant sensory changes and another with cardiopathy, showed degeneration of peripheral nerve and mixed features in muscle biopsy. It is postulated that the myopathic or dystrophic features in the muscle of these cases and other patients with scapuloperoneal syndrome is likely to be secondary to slow denervation and reinnervation.

Aortic regurgitation and pigmentation - unusual features of Noonan syndrome.

A patient with typical features of Noonan's syndrome showed aortic regurgitation and widespread diffuse hyperpigmentation, features not previously associated with this syndrome. Detailed endocrine and dermatological studies failed to delineate the cause of hyperpigmentation. In addition to mild aortic regurgitation, cardiac catheterization revealed mild left ventricular dysfunction, probably due to primary myocardial disease. Other interesting findings included lymphedema and sexual infantilism despite normal testosterone levels.

Detection of Mycoplasma fermentans in human saliva with a polymerase chain reaction-based assay.

Mycoplasma fermentans and other mycoplasma species may be associated with human immunodeficiency virus infection. Little is known about the ecology of this micro-organism and its natural habitat. A polymerase chain reaction (PCR)-based assay was used to detect M. fermentans in whole saliva. The hypothesis was tested that M. fermentans is present on the mucosal surfaces of the mouth and oropharynx. Whole saliva was collected from 110 adults. The 206-bp amplification product of DNA purified from these samples was detected in ethidium bromide-stained 6% polyacrylamide gels in 49 (44%) samples tested. All samples were confirmed by Southern blotting with a probe based on an internal sequence of the expected amplification product. The data suggest that this organism is often found in saliva and on oropharyngeal mucosal surfaces. Saliva may play a part in its transmission between individuals. Saliva sampling may be helpful in further studies of the ecology and distribution of the micro-organism in human populations.

Isolation and characterization of coaggregation-defective mutants of Veillonella atypica.

Spontaneously occurring coaggregation-defective mutants of Veillonella atypica PK1910 were isolated and used to study the interactions of veillonella with Streptococcus sanguis, Strep. gordonii and Strep. SM. Three classes of mutants were isolated. The first class failed to participate in lactose-inhibitable coaggregations with streptococcal cells. The second class of mutants failed to coaggregate by the lactose-non-inhibitable interactions. The third group, isolated from the first group, failed to coaggregate with any of the oral streptococci. Based on the coaggregation phenotypes of these mutants, a model for veillonella-streptococcal coaggregations is proposed, in which two distinct surface molecules mediate three types of interactions with the oral streptococci.

Risk factors and late recurrence of angina following myocardial revascularization.

To assess the influence of risk factors on the recurrence of angina several years after myocardial revascularization, 316 patients were studied. We report that 249 patients obtained relief of angina from coronary bypass surgery and remained free of angina up to 4 years later. The remaining 67 patients experienced initial relief of angina 1 year following bypass surgery and then, subsequently, redeveloped angina 4 years postsurgery. There was no statistical difference in any risk factor between patients who remained free of angina after myocardial revascularization and those who developed angina. Of the total 316 patients, 79% were free of angina 4 years after coronary bypass surgery.

Reasons for dental extractions in children.

PURPOSE: The purpose of this study was to investigate the principal reason for primary tooth extraction and the tooth type most frequently extracted in children aged 3-13 years. METHODS: The patients selected for this retrospective study were identified by analyzing dental records of children receiving treatment at Franciscan Children's Hospital & Rehabilitation Center, Boston, MA (FCH & RC). In total, 2,000 records were reviewed, and 567 extracted primary teeth were analyzed from 277 patients who had at least one primary tooth extracted under local anesthesia. The criteria for inclusion in this study included children between the ages of 3 and 13 years. RESULTS: First primary molars were the most common tooth type extracted and comprised 30% of teeth removed. Central incisors were the next common tooth type extracted and accounted for 25% of the extractions. There was no difference, by gender, in the extraction of tooth type but there were striking differences according to age. Almost half of the primary teeth extracted in subjects 3 to 5 years were incisors, and in patients 6 to 9 years the first primary molar was the most common tooth type extracted. Molars were the tooth type most frequently extracted from those patients aged 10 to 13 years. There were significant differences in the reasons for extraction of various tooth types, and, while extractions due to caries predominated overall, this was not the case for all tooth types. CONCLUSIONS: This study has concluded that despite the dramatic improvements in pediatric oral health over the last decades, caries and the resulting pulpal pathology remains the most common reason for extraction of primary teeth.

IgA antibodies to Streptococcus mutans in caries-resistant and -susceptible children.

Previous studies have shown a positive correlation between salivary IgA antibody levels to Streptococcus mutans and caries resistance in adults. In this study, enzyme-linked immunosorbent assay (ELISA) was used to compare IgA antibody levels with S. mutans in whole and parotid saliva from 20 caries-susceptible (CS; DMFS > 5) and 20 caries-resistant (CR; DMFS < or = 1) children (aged 7-11 years). Whole salivary S. mutans numbers were significantly greater (P < or = 0.05) in the CS group (mean of 31.2% of total oral streptococci) than in the CR group (mean of 1.6% of total oral streptococci). Whole saliva, but not parotid saliva, from CR children had significantly higher (P < or = 0.05) levels of IgA antibodies to S. mutans than saliva from CS children. These results suggest that salivary IgA antibodies to S. mutans may play a role in natural protection from dental caries in children and that the source of increased salivary IgA antibody in CR children may be either the minor, submandibular, or sublingual salivary glands.

Future caries susceptibility in children with early childhood caries following treatment under general anesthesia.

PURPOSE: The purpose of this study was to assess the susceptibility of children to the future development of caries following comprehensive treatment for early childhood caries (ECC) under general anesthesia. METHODS: The patients selected for this retrospective study were identified by analyzing dental records of children receiving treatment at the Franciscan Children's Hospital & Rehabilitation Center, Boston, MA (FCH & RC). In total, 4,143 records were reviewed. Of these, ECC was diagnosed in 42 patients before their admission to the operating room. Thirty-one control children were selected randomly from the dental records reviewed at FCH & RC. The control group was initially caries-free. The caries status of the children diagnosed with ECC was evaluated and compared with the control group. Children in both groups were seen for recall at intervals of six to nine months over a two-year period. The carious lesions were recorded in two categories; new smooth surface caries (NSSC) and new pit and fissure caries (NPFC). RESULTS: Thirty-three of 42 (79%) ECC children compared to nine of 31 (29%) control children had detectable carious lesions at subsequent recall visits. Children with ECC demonstrated a mean number of 3.2 +/- 3.3 new carious lesions compared to a mean of only 0.8 +/- 1.6 carious lesions in the control group. These differences were statistically significant (t71 = 3.8; P < 0.001). In addition, of the 42 patients treated for ECC under general anesthesia, seven (17%) required retreatment under general anesthesia within two years following their initial full-mouth rehabilitation. The prevalence of NSSC in the ECC group was significantly higher than the control group (t71 = 3.5; P < 0.001). CONCLUSIONS: Despite increased preventive measures implemented for children who experienced ECC, this study concluded that this group of children is still highly predisposed to greater caries incidence in later years. These findings strongly suggest that more aggressive preventive therapies may be required to prevent the future development of carious lesions in children who experienced ECC.

Microbiota of severe early childhood caries before and after therapy.

Severe early childhood caries (ECC) is difficult to treat successfully. This study aimed to characterize the microbiota of severe ECC and evaluate whether baseline or follow-up microbiotas are associated with new lesions post-treatment. Plaque samples from 2- to 6-year-old children were analyzed by a 16S rRNA-based microarray and by PCR for selected taxa. Severe-ECC children were monitored for 12 months post-therapy. By microarray, species associated with severe-ECC (n = 53) compared with caries-free (n = 32) children included Slackia exigua (p = 0.002), Streptococcus parasanguinis (p = 0.013), and Prevotella species (p < 0.02). By PCR, severe-ECC-associated taxa included Bifidobacteriaceae (p < 0.001), Scardovia wiggsiae (p = 0.003), Streptococcus mutans with bifidobacteria (p < 0.001), and S. mutans with S. wiggsiae (p = 0.001). In follow-up, children without new lesions (n = 36) showed lower detection of taxa including S. mutans, changes not observed in children with follow-up lesions (n = 17). Partial least-squares modeling separated the children into caries-free and two severe-ECC groups with either a stronger bacterial or a stronger dietary component. We conclude that several species, including S. wiggsiae and S. exigua, are associated with the ecology of advanced caries, that successful treatment is accompanied by a change in the microbiota, and that severe ECC is diverse, with influences from selected bacteria or from diet.

Diet and caries-associated bacteria in severe early childhood caries.

Frequent consumption of cariogenic foods and bacterial infection are risk factors for early childhood caries (ECC). This study hypothesized that a short diet survey focused on frequency of foods, categorized by putative cariogenicity, would differentiate severe ECC (S-ECC) from caries-free children. Children's diets were obtained by survey and plaque bacteria detected by PCR from 72 S-ECC and 38 caries-free children. S-ECC children had higher scores for between-meal juice (p < 0.01), solid-retentive foods (p < 0.001), eating frequency (p < 0.005), and estimated food cariogenicity (p < 0.0001) than caries-free children. S-ECC children with lesion recurrence ate fewer putative caries-protective foods than children without new lesions. Streptococcus mutans (p < 0.005), Streptococcus sobrinus (p < 0.005), and Bifidobacteria (p < 0.0001) were associated with S-ECC, and S. mutans with S. sobrinus was associated with lesion recurrence (p < 0.05). S. mutans-positive children had higher food cariogenicity scores. Food frequency, putative cariogenicity, and S. mutans were associated with S-ECC individually and in combination.

Mutational analysis of the adcCBA genes in Streptococcus gordonii biofilm formation.

Streptococcus gordonii, a primary colonizer, is part of the pioneer biofilm consortium that initiates dental plaque development on tooth surfaces. An insertion of Tn917-lac transposon into the adcR gene produced a biofilm-defective phenotype. S. gordonii adcR is a regulatory gene and is part of an operon (adc) that includes three other genes, adcCBA. AdcC contains a putative consensus-binding site for adenosine triphosphate, AdcB is a putative hydrophobic membrane protein, and AdcA is a putative lipoprotein permease. Mutants were constructed by insertional inactivation in each of the three adcCBA genes and their effects on biofilm formation examined. The adcC::spec(R) and adcB::spec(R) mutations displayed a biofilm-defective phenotype, whereas the adcA::spec(R) mutant was biofilm-positive in a static polystyrene microtiter plate biofilm assay. All three mutants formed poor biofilms in a flow-cell system and were competence-defective, suggesting the adc operon plays an important role in S. gordonii biofilm formation and competence.