Stercoral perforation proximal to the stapled anastomosis after low anterior resection with an intraluminal device.

Stercoral perforation of the colon is a rare phenomenon and a potential life-threatening condition requiring acute intervention. A little more than 200 cases have been described to date. The mechanism is not completely understood. In this short communication, we present three patients with a colon perforation proximal to the anastomosis, similar to a stercoral perforation, following colorectal cancer resection with application of an intraluminal device, the C-seal.

Randomized clinical trial of biodegradeable intraluminal sheath to prevent anastomotic leak after stapled colorectal anastomosis.

BACKGROUND: Anastomotic leakage is a potential major complication after colorectal surgery. The C-seal was developed to help reduce the clinical leakage rate. It is an intraluminal sheath that is stapled proximal to a colorectal anastomosis, covering it intraluminally and thus preventing intestinal leakage in case of anastomotic dehiscence. The C-seal trial was initiated to evaluate the efficacy of the C-seal in reducing anastomotic leakage in stapled colorectal anastomoses. METHODS: This RCT was performed in 41 hospitals in the Netherlands, Germany, France, Hungary and Spain. Patients undergoing elective surgery with a stapled colorectal anastomosis less than 15 cm from the anal verge were eligible. Included patients were randomized to the C-seal and control groups, stratified for centre, anastomotic height and intention to create a defunctioning stoma. Primary outcome was anastomotic leakage requiring invasive treatment. RESULTS: Between December 2011 and December 2013, 402 patients were included in the trial, 202 in the C-seal group and 200 in the control group. Anastomotic leakage was diagnosed in 31 patients (7·7 per cent), with a 10·4 per cent leak rate in the C-seal group and 5·0 per cent in the control group (P = 0·060). Male sex showed a trend towards a higher leak rate (P = 0·055). Construction of a defunctioning stoma led to a lower leakage rate, although this was not significant (P = 0·095). CONCLUSION: C-seal application in stapled colorectal anastomoses does not reduce anastomotic leakage. Registration number: NTR3080 (http://www.trialregister.nl/trialreg/index.asp).

High mortality rates after nonelective colon cancer resection: results of a national audit.

AIM: Colon cancer resection in a nonelective setting is associated with high rates of morbidity and mortality. The aim of this retrospective study is to identify risk factors for overall mortality after colon cancer resection with a special focus on nonelective resection. METHOD: Data were obtained from the Dutch Surgical Colorectal Audit. Patients undergoing colon cancer resection in the Netherlands between January 2009 and December 2013 were included. Patient, treatment and tumour factors were analysed in relation to the urgency of surgery. The primary outcome was 30-day postoperative mortality. RESULTS: The study included 30 907 patients. A nonelective colon cancer resection was performed in 5934 (19.2%) patients. There was a 4.4% overall mortality rate, with significantly more deaths after nonelective surgery (8.5% vs 3.4%, P < 0.001). Older patients, male patients and patients with high comorbidity, advanced tumours, perforated tumours, a tumour in the right or transverse colon and postoperative anastomotic leakage were at risk of postoperative death. In nonelective resections, a right-sided tumour and postoperative anastomotic leakage were associated with high mortality. CONCLUSION: Nonelective colon cancer resection is associated with high mortality. In particular, right-sided resections and patients with tumour perforation are at particularly high risk. The optimization of patients prior to surgery and expeditious operation after diagnosis might prevent the need for a nonelective resection.

Fragile X mice have robust mGluR5-dependent alterations of social behaviour in the Automated Tube Test.

Fragile X syndrome is the most common monogenetic form of intellectual disability and autism. Although the Fmr1 knockout mouse model recapitulates many aspects of the human FXS condition, the establishment of robust social behavioural phenotypes suitable for drug screening has been difficult. Here, we describe a novel social behavioural paradigm, the Automated Tube Test (ATT), for which Fmr1 knockout mice demonstrate a highly reliable and robust phenotype. Fmr1 KO mice show highly dominant behaviour over wild-type littermates in the ATT. Consistent with previous findings, we observed a highly significant, albeit partial, rescue of the altered social behaviour of Fmr1 knockout mice in the ATT, using genetic (mGluR5 deletion) or pharmacological inhibition (mGluR5 antagonist) of mGluR5 signalling independently. Together, our results validate the Automated Tube Test as a robust outcome measure for social behaviour in preclinical research for FXS, and confirm the pathophysiological relevance of mGluR5 signalling. Moreover, our findings highlight the strategy of initiating pharmacological intervention in adulthood as holding significant clinical potential.

High complication rate after low anterior resection for mid and high rectal cancer; results of a population-based study.

BACKGROUND: Surgical resection is the cornerstone of treatment for rectal cancer patients. Treatment options consist of a primary anastomosis, anastomosis with defunctioning stoma or end-colostomy with closure of the distal rectal stump. This study aimed to compare postoperative outcome of these three surgical options. METHODS: Data was derived from the national database of the Dutch Surgical Colorectal Audit. Mid and high rectal cancer patients who underwent rectal cancer resection between January 2011 and December 2012 were included. Endpoints were postoperative complications including anastomotic leakage, reinterventions, hospital stay and mortality within 30 days postoperative. RESULTS: In total, 2585 patients were included. Twenty-five per cent of all patients received a primary anastomosis; 51% an anastomosis with defunctioning stoma, and 24% an end-colostomy. More than one third of patients developed postoperative complications, the lowest rate being in the primary anastomosis group. Anastomotic leakage rates were 12% in patients with a primary anastomosis, and 9% in patients with an anastomosis with defunctioning stoma (p < 0.05). Multivariate analysis showed more postoperative complications, prolonged hospital stay, and increased mortality rates in patients with a defunctioning stoma or end-colostomy. The latter had proportionally less invasive reinterventions when compared to the other two groups. CONCLUSIONS: Patients with a primary anastomosis had the best postoperative outcome. A defunctioning stoma leads to a lower anastomotic leakage rate, though is associated with higher rates of complications, prolonged hospital stay and mortality. The decision to create a defunctioning stoma should be focus of future studies.

Risk factors for anastomotic leakage and leak-related mortality after colonic cancer surgery in a nationwide audit.

BACKGROUND: Surgical resection with restoration of bowel continuity is the cornerstone of treatment for patients with colonic cancer. The aim of this study was to identify risk factors for anastomotic leakage (AL) and subsequent death after colonic cancer surgery. METHODS: Data were retrieved from the Dutch Surgical Colorectal Audit. Patients undergoing colonic cancer resection with creation of an anastomosis between January 2009 to December 2011 were included. Outcomes were AL requiring reintervention and postoperative mortality following AL. RESULTS: AL occurred in 7·5 per cent of 15 667 patients. Multivariable analyses identified male sex, high American Society of Anesthesiologists (ASA) fitness grade, extensive tumour resection, emergency surgery, and surgical resection types such as transverse resection, left colectomy and subtotal colectomy as independent risk factors for AL. A defunctioning stoma was created in a small group of patients, leading to a lower risk of leakage. The mortality rate was 4·1 per cent overall, and was significantly higher in patients with AL than in those without leakage (16·4 versus 3·1 per cent; P < 0·001). Multivariable analyses identified older age, high ASA grade, high Charlson score and emergency surgery as independent risk factors for death after AL. The adjusted risk of death after AL was twice as high following right compared with left colectomy. CONCLUSION: The elderly and patients with co-morbidity have a higher risk of death after AL. Accurate preoperative patient selection, intensive postoperative surveillance for AL, and early and aggressive treatment of suspected leakage is important, especially in patients undergoing right colectomy.

High 1-year complication rate after anterior resection for rectal cancer.

BACKGROUND: Surgical options after anterior resection for rectal cancer include a primary anastomosis, anastomosis with a defunctioning stoma, and an end colostomy. This study describes short-term and 1-year outcomes of these different surgical strategies. METHODS: Patients undergoing surgical resection for primary mid and high rectal cancer were retrospectively studied in seven Dutch hospitals with 1-year follow-up. Short-term endpoints were postoperative complications, re-interventions, prolonged hospital stay, and mortality. One-year endpoints were unplanned readmissions and re-interventions, presence of stoma, and mortality. RESULTS: Nineteen percent of 388 included patients received a primary anastomosis, 55% an anastomosis with defunctioning stoma, and 27% an end colostomy. Short-term anastomotic leakage was 10% in patients with a primary anastomosis vs. 7% with a defunctioning stoma (P = 0.46). An end colostomy was associated with less severe re-interventions. One-year outcomes showed low morbidity and mortality rates in patients with an anastomosis. Patients with a defunctioning stoma had high (18%) readmissions and re-intervention (12%) rates, mostly due to anastomotic leakage. An end colostomy was associated with unplanned re-interventions due to stoma/abscess problems. During follow-up, there was a 30% increase in patients with an end colostomy. CONCLUSIONS: This study showed a high 1-year morbidity rate after anterior resection for rectal cancer. A defunctioning stoma was associated with a high risk for late complications including anastomotic leakage. An end colostomy is a safe alternative to prevent anastomotic leakage, but stomal problems cannot be ignored. Selecting low-risk patients for an anastomosis may lead to favorable short- and 1-year outcomes.

Exome sequencing is a useful diagnostic tool for complicated forms of hereditary spastic paraplegia.

Hereditary spastic paraplegias constitute a heterogeneous group of neurodegenerative diseases encompassing pure and complicated forms, for which at least 52 loci and 31 causative genes have been identified. Although mutations in the SPAST gene explain approximately 40% of the pure autosomal dominant forms, molecular diagnosis can be challenging for the sporadic and recessive forms, which are often complicated and clinically overlap with a broad number of movement disorders. The validity of exome sequencing as a routine diagnostic approach in the movement disorder clinic needs to be assessed. The main goal of this study was to explore the usefulness of an exome analysis for the diagnosis of a complicated form of spastic paraplegia. Whole-exome sequencing was performed in two Spanish siblings with a neurodegenerative syndrome including upper and lower motor neuron, ocular and cerebellar signs. Exome sequencing revealed that both patients carry a novel homozygous nonsense mutation in exon 15 of the SPG11 gene (c.2678G>A; p.W893X), which was not found in 584 Spanish control chromosomes. After many years of follow-up and multiple time-consuming genetic testing, we were able to diagnose these patients by making use of whole-exome sequencing, showing that this is a cost-efficient diagnostic tool for the movement disorder specialist.

Computerization of a dietary history interview in a running cohort; evaluation within the Amsterdam Growth and Health Longitudinal Study.

OBJECTIVE: In nutritional research, a growing interest in the use of computer-assisted cross-check dietary history interview methods exists in order to improve cost-effectiveness. The introduction of such a method in an ongoing longitudinal study was evaluated with special emphasis on the effect on interviewer bias. DESIGN: A study for the interviewer bias within and the agreement between a previously used paper-based face-to-face cross-check dietary history interview method and a newly developed interviewer-administered computer-assisted version of this interview method. SUBJECTS: The interviewer bias of 436 face-to-face interviews is compared with that of 352 computer-assisted interviews. A subset of 82 subjects underwent a face-to-face interview at the mean age of 27 and 32 y and a computer-assisted interview at their mean age of 36 y. Energy, three macronutrients (protein, fat and carbohydrate), two micronutrients (calcium and iron) and alcohol intakes obtained by these three measurements are compared to analyse the agreement between the two interview methods. RESULTS: ANOVA showed no interviewer bias for all seven analysed nutrients within the data from the computer-assisted interview, while for the face-to-face interview method, several nutrients varied significantly among the interviewers. Five different measures, used to analyse the agreement (differences, Pearson's correlation, ICC, square weighted kappa and Bland-Altman plots), showed no relevant differences between the two cross-check dietary history interview methods. CONCLUSIONS: It is concluded that the computer-assisted interview caused a reduction of interviewer bias and is of similar quality to the face-to-face interview method. Computerization of a paper-based interview can be implemented in a running cohort if a change in method is unavoidable.

Validation of a physical activity questionnaire to measure the effect of mechanical strain on bone mass.

Most of the questionnaires available to estimate the daily physical activity levels of humans are based on measuring the intensity of these activities as multiples of resting metabolic rate (METs). Metabolic intensity of physical activities is the most important component for evaluating effects on cardiopulmonary fitness. However, animal studies have indicated that for effects on bone mass the intensity in terms of energy expenditure (metabolic component) of physical activities is less important than the intensity of mechanical strain in terms of the forces by the skeletal muscles and/or the ground reaction forces. The physical activity questionnaire (PAQ) used in the Amsterdam Growth and Health Longitudinal Study (AGAHLS) was applied to investigate the long-term effects of habitual physical activity patterns during youth on health and fitness in later adulthood. The PAQ estimates both the metabolic components of physical activities (METPA) and the mechanical components of physical activities (MECHPA). Longitudinal measurements of METPA and MECHPA were made in a young population of males and females ranging in age from 13 to 32 years. This enabled evaluation of the differential effects of physical activities during adolescence (13-16 years), young adulthood (21-28 years), and the total period of 15 years (age 13-28 years) on bone mineral density (BMD) of the lumbar spine, as measured by dual-energy X-ray absorptiometry (DXA) in males (n = 139) and females (n = 163) at a mean age of 32 years. The PAQ used in the AGAHLS during adolescence (13-16 years) and young adulthood (21-28 years) has the ability to measure the physical activity patterns of both genders, which are important for the development of bone mass at the adult age. MECHPA is more important than METPA. The highest coefficient of 0.33 (p < 0.01) was between MECHPA measured over the total period of 15 years (13-28 years) and lumbar BMD at age 32 years. Only during adolescence (12-16 years) was METPA more important with regard to lumbar BMD at age 32 years, with a beta of 0.21 (p < 0.01). The relative validity of the PAQ was established by comparing PAQ scores during four annual measurements in 200 boys and girls with two other objective measures of physical activity: movement counters (pedometers) and heart rate monitoring. These showed significant (p < 0.01) correlations in both genders, varying between 0.16 and 0.20. The small variation indicates, however, that all three instruments measure different aspects of physical activity. The results from the PAQ, with respect to MECHPA, validated in humans the results from animal studies in which bone adaptation during skeletal growth and development continuously adjust skeletal mass and architecture to changing mechanical stimuli caused by physical activity.

Transport of ground-state hydrogen atoms in a plasma expansion.

The transport of ground-state atomic hydrogen in the expansion of a thermal plasma generated from an Ar-H2 mixture is studied by means of laser-based diagnostic techniques. The flow of hydrogen atoms is investigated by two-photon excitation laser-induced fluorescence (LIF), whereas Ar atoms are probed by LIF as well as by UV Rayleigh scattering. The transport of Ar atoms can be fully understood in terms of a free jet flow; H atoms on the contrary exhibit an anomalous behavior. In the course of the plasma expansion, hydrogen atoms decouple from the argon fluid by a diffusion process as a direct consequence of recombination of H atoms at the vessel walls. In this contribution it is shown, on the basis of experimental results, how plasma-surface interactions can strongly influence the flow pattern of an atomic radical fluid.

Relationship between herpesviruses and adult periodontitis and periodontopathic bacteria.

BACKGROUND: Various mammalian viruses and specific bacteria seem to play important roles in the pathogenesis of human periodontitis. This study examined the relationship between subgingival herpesviruses and periodontal disease and potential periodontopathic bacteria in 140 adults exhibiting either periodontitis or gingivitis. METHODS: A nested-polymerase chain reaction (PCR) method determined the presence of Epstein-Barr virus type 1 and type 2 (EBV-1, EBV-2), human cytomegalovirus (HCMV), and herpes simplex virus (HSV) and a 16S rRNA PCR detection method identified Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, Prevotella intermedia, Prevotella nigrescens, and Treponema denticola. RESULTS: Using a logistic analysis, EBV-1 showed significant positive association with P. gingivalis (odds ratio [OR] 3.37), and with coinfections of P. gingivalis and P. intermedia (OR 4.03); P. gingivalis and B. forsythus (OR 3.84); P. gingivalis and T. denticola (OR 4.17); P. gingivalis, B. forsythus, and T. denticola (OR 4.06); and P. gingivalis, P. nigrescens, and T. denticola (OR 3.29). EBV-1 also showed positive association with severe periodontitis (OR 5.09), with increasing age (OR 1.03), and with periodontal probing depth at the sample sites (OR 1.77). HCMV was positively associated with coinfections of P. gingivalis and P. nigrescens (OR 3.23); P. gingivalis, B. forsythus, and P. nigrescens (OR 3.23); and P. gingivalis, P. nigrescens, and T. denticola (OR 2.59); with severe periodontitis (OR 4.65); and with age (OR 1.03). Patients with mixed viral infections revealed significant associations with P. gingivalis (OR 2.27), and with coinfections of P. gingivalis and B. forsythus (OR 2.06); P. gingivalis and P. nigrescens (OR 2.91); P. gingivalis, B. forsythus, and P. nigrescens (OR 2.91); and P. gingivalis, P. nigrescens, and T. denticola (OR 2.70) with the clinical diagnosis of slight (OR 3.73), moderate (OR 3.82), or severe periodontitis (OR 4.36), and with probing depth at the sample sites (OR 1.39). HSV and EBV-2 showed no significant associations with any of the variables tested. CONCLUSIONS: The results indicate that subgingival EBV-1, HCMV, and viral coinfections are associated with the subgingival presence of some periodontal pathogens and periodontitis. Herpesviruses may exert periodontopathic potential by decreasing the host resistance against subgingival colonization and multiplication of periodontal pathogens.

Risk indicators for harboring periodontal pathogens.

The risk for harboring 6 putative periodontal pathogens in 4 selected periodontal pockets, in whole saliva, or in either site (i.e., orally) was determined in 52 Caucasians, 49 African-Americans, 48 Asian-Americans, and 50 Hispanics living in Los Angeles. 16S rRNA PCR analysis assessed the presence of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, and Treponema denticola. Step-wise regression analysis determined the relationship between the occurrence of each organism and various explanatory variables (risk indicators). Periodontal probing depth or disease severity was positively associated with all 6 study organisms. African-Americans carried an increased risk for harboring P. gingivalis in saliva (odds ratio [OR] 2.95) and orally (OR 2.66), and a reduced risk for harboring T. denticola orally (OR 0.34). Asian-Americans showed an increased risk for harboring A. actinomycetemcomitans in periodontal pockets (OR 6.63) and P. gingivalis in periodontal pockets (OR 5.39), in saliva (OR 5.74), and orally (OR 5.81). Hispanics demonstrated an increased risk for harboring A. actinomycetemcomitans in periodontal pockets (OR 12.27) and P. gingivalis in periodontal pockets (OR 6.07), in saliva (OR 8.72), and orally (OR 7.98). Age was positively associated with the prevalence of P. gingivalis in saliva (OR 1.20) and orally (OR 1.20), and of A. actinomycetemcomitans orally (OR 1.18). The male gender was a risk factor for harboring P. intermedia in periodontal pockets (OR 2.40), in saliva (OR 3.31), and orally (OR 4.25), and for harboring P. nigrescens in saliva (OR 2.85). The longer the subjects resided in the United States, the less likely A. actinomycetemcomitans was detected orally (OR 0.82). Former smokers demonstrated a decreased risk for harboring A. actinomycetemcomitans in saliva (OR 0.23). Current smokers displayed an increased risk for harboring T. denticola in periodontal pockets (OR 4.61). The number of dental visits in the past 10 years was inversely related to the prevalence of P. intermedia orally (OR 0.96). The prevalence of P. intermedia in saliva was positively associated with the length of time from the last dental visit (OR 1.01). This study suggests that genetic and/or environmental factors predispose subjects to oral colonization by putative periodontal pathogens.

The utility of whole saliva to detect the oral presence of periodontopathic bacteria.

This study compared the presence of 6 periodontopathic bacteria in whole saliva and subgingival plaque of 202 subjects. The test bacteria were identified using a 16S rRNA-based PCR detection method. Each study subject contributed a whole saliva sample and a paper point sample pooled from the deepest periodontal pocket in each quadrant of the dentition. The kappa test revealed a fair agreement between the presence of Porphyromonas gingivalis, Prevotella intermedia, and Treponema denticola in whole saliva and periodontal pocket samples (kappa > 0.4). The McNemar test showed that the differences between sample types were due to a more frequent detection of the 3 organisms in whole saliva than in periodontal pocket samples (P < 0.01). Prevotella nigrescens also was detected more frequently in whole saliva than in periodontal pocket samples (P < 0.01; McNemar test). Although little agreement between samples was found for Actinobacillus actinomycetemcomitans and Bacteroides forsythus (kappa < or = 0.4), neither whole saliva nor pocket samples showed better detection for these 2 species (P < 0.01, McNemar test). The results indicate that whole saliva is superior to pooled periodontal pocket samples to detect P. gingivalis, P. intermedia, P. nigrescens, and T. denticola in the oral cavity. The detection of oral A. actinomycetemcomitans and B. forsythus with reasonably good accuracy may require both whole saliva and periodontal pocket samples.

Effects of ritual abuse: the results of three surveys in The Netherlands.

OBJECTIVE: We decided to document the behavior of 87 children involved in multiple victim/multiple perpetrator sexual abuse by developing and administering surveys to families. Data gathered at 2 1/2 years (1990) and 7 years (1994) after the disclosures indicated the behavioral status of the children at different developmental stages. This data was compared to clinical information available prior to the abuse, and initial survey data rendered at 6 weeks after disclosure (Jonker & Jonker-Bakker, 1991). The objective was to document the behavior of the victims during the healing process. METHODOLOGY: A questionnaire was sent to the parents of 87 children who were abused in 1987. The parents returned the completed questionnaire, and were interviewed in our clinic. RESULTS: Data from the 1990 and 1994 surveys indicate that 39% of the children involved, who lived in supportive family environments, had changed as a result of the abuse. They exhibited behavior within acceptable, normal guidelines for childhood development. In 1994, 7% of the children involved showed signs of more severe behavioral disorders. CONCLUSIONS: The findings indicate that physical and behavioral signs apparent in the 1990 and 1994 surveys were not recognized at the time the abuse occurred. Many of the children exhibit normal, acceptable behavior at the time of the most recent survey (1994).

Insulin receptor mRNA splicing and altered metabolic control in aged and mildly insulin-deficient rats.

Using reverse transcription-competitive polymerase chain reaction, we measured the abundance of the mRNAs encoding the two spliced isoforms of insulin receptor in aged and mildly insulin-deficient rats. Twelve-month-old rats were characterized by peripheral insulin resistance and decreased glucose tolerance. Mild insulin deficiency, obtained by neonatal streptozotocin treatment, was associated with glucose intolerance due to reduced glucose-stimulated insulin response. Both models were associated with a decrease in the relative abundance of the mRNA with exon 11 in liver, heart, adipose tissue, and tibialis muscle, whereas a slight increase was seen in the extensor digitorum longus and no change in the soleus muscle. In the three muscles, the expression of the form without exon 11 largely predominated (>90%). In heart and adipose tissue, the two isoforms were expressed at a similar level in control rats. In both tissues, the form without exon 11 increased in streptozotocin-treated rats, whereas the absolute level of the form with exon 11 decreased in old rats. Although a decreased level of the variant with exon 11 correlated with insulin resistance of whole body glucose uptake, our results indicated that changes in the expression of the insulin receptor variants were secondary events and thus not the cause of the insulin resistance in old and mildly insulin-deficient rats.

Measurement of menopausal hot flushes: validation and cross-validation.

Specificity and sensitivity of two physiological markers for hot flushes were investigated. One marker, proposed by Freedman, is an increase of sternal skin conductance, the second marker, proposed by Swartzman, is a physiological profile which consists of skin conductance changes in combination with circulation changes. In our laboratory 20 menopausal women, 15 with frequent hot flushes and 5 without hot flushes, and 5 women with regular menstrual cycles were continuously monitored for 2.5 h on subjective hot flush experience, sternal and palmar skin conductance, dorsal and palmar finger temperature and pulse blood volume. Increase in sternal skin conductance proved to be very specific in contrast to Swartzman's physiological profile, although it was less sensitive. Receiver operating characteristics revealed that an increase combined with a preceding decrease in sternal skin conductance as most specific for, and most sensitive to, subjectively reported hot flushes. This was confirmed by a cross-validation with 34 "flushing' menopausal women.

Polymerase chain reaction detection of 8 putative periodontal pathogens in subgingival plaque of gingivitis and advanced periodontitis lesions.

A 16S rRNA-based polymerase chain reaction (PCR) detection method was used to determine the prevalence of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Campylobacter rectus, Eikenella corrodens, Porphyromonas gingivalis, Prevotella intermedia. Prevotella nigrescens and Treponema denticola in subgingival specimens of 50 advanced periodontitis, 50 adult gingivitis and 50 pediatric gingivitis subjects. The optimal PCR conditions were determined for each study species. Agarose gel electrophoresis of PCR products from each study species revealed a single band of the predicted size. Restriction enzyme digestion of amplicons confirmed the specificity of the amplification. PCR detection limits were in the range of 25-100 cells. No cross-reactivity with other oral micro-organisms or nonspecific amplification was observed. The prevalence by PCR in advanced periodontitis, adult gingivitis and pediatric gingivitis subjects was 30%, 14% and 14% for A. actinomycetemcomitans, 86%, 18% and 8% for B. forsythus, 74%, 52% and 78% for C. rectus, 80%, 70% and 66% for E. corrodens, 70%, 10% and 14% for P. gingivalis, 58%, 12% and 18% for P. intermedia, 52%, 20% and 22% for P. nigrescens, and 54%, 16% and 16% for T. denticola, respectively. The prevalence was higher in the advanced periodontitis group than in both adult gingivitis and pediatric gingivitis for A. actinomycetemcomitans, B. forsythus, P. gingivalis, P. intermedia, P. nigrescens and T. denticola at P < 0.01, and for E. corrodens at P < 0.05. The prevalence of C. rectus was significantly higher in the advanced periodontitis group than in the adult gingivitis group at P < 0.01. Matching results between PCR and culture occurred in 28% (B. forsythus) to 71% (A. actinomycetemcomitans) of the samples; the major discrepancy occurred in the PCR-positive/culture-negative category. Matching results between PCR and DNA probe methods were found in 84% of the subjects (B. forsythus) and 70% (P. gingivalis). Odds ratio analysis revealed statistically significant positive associations between 17 of the 28 possible combinations (P < 0.01). This study demonstrated the utility of a 16S rRNA-based PCR detection method for identifying important subgingival microorganisms. The results indicated a strong association between the study species and periodontitis. Several previously unreported symbiotic relationships were found between the 8 species tested.

Effect of high fat feeding on glucose tolerance in neonatally streptozotocin-treated rats at 3 and 6 months of age.

In the rat, a high fat intake is believed to be associated with an increased risk for the development of glucose intolerance by inducing insulin resistance. The aim of this study was to investigate whether reduced insulin production may also play a role. Rats were treated with 0, 30, 60, and 90 mg of streptozotocin (STZ)/kg of body weight on the day of birth (0, 30, 60, and 90 nSTZ rats). At 3 or 6 months of age, glucose tolerance was assessed by the intravenous glucose tolerance test (IVGTT). STZ dose-dependently decreased first- and second-phase insulin responses and correspondingly impaired glucose tolerance. Following a 3-week high fat diet (HFD: 60% of calories as corn oil), insulin responses were higher in control as well as in STZ-treated rats both at 3 and 6 months of age. In 3-month-old rats this was accompanied by unchanged or increased glucose levels following the glucose load, whereas in 6-month-old 0 and 30 nSTZ rats glucose tolerance was slightly improved. After 6 weeks of HFD in 6-month-old rats, glucose tolerance was impaired compared to that after 3 weeks of HFD despite higher insulin responses. Continuing the HFD for up to 12 weeks further impaired glucose tolerance, but insulin responses were decreased compared to those after 6 weeks of HFD. These results indicate that very low dose neonatal STZ administration impairs glucose tolerance through decreased overall insulin responses. This may possibly be due to a reduction of B-cell number rather than an alteration of B-cell function. No clear evidence exists that a high fat intake per se negatively influences glucose-induced insulin responses, but this may become apparent after longer periods of high fat feeding.