Expression of a cytokine, interleukin-23, in experimental periapical lesions

AIM

To investigate the expression of interleukin (IL)-23, a new member of the IL-12 family, in experimental periapical lesions.

METHODOLOGY

Periapical lesions were induced in Wistar rats by occlusal surface pulp exposure in mandibular first molars. The rats were randomly sacrificed 0, 7, 14, 21, 28, 35, 42 and 56 days after pulp exposure. The jaws that contained the first molars were obtained and routinely prepared for radiographic, histological, enzyme histochemical, immunohistochemical and double immunofluorescence analyses. Data were analysed by one-way analysis of variance and the Pearson correlation test.

RESULTS

The number of IL-23-positive cells increased from day 7 to day 35 and then gradually decreased. The number of osteoclasts increased and peaked on day 14 and then gradually decreased from day 21 to day 56. A significant positive correlation existed between the number of IL-23 positive cells and the size of bone resorption in periapical lesions from day 7 to day 56 (r = 0.875, P < 0.01).

CONCLUSIONS

Interleukin-23 can be observed and may be associated with inflammatory response and bone resorption in periapical lesions.

Comparison of spermatogenic damage induced at 6 months after ligation of the vas deferens at proximal and distal locations in the rabbit

Recent study in rabbits demonstrated that vasectomy via the inguinal canal did not result in any spermatogenic damage 3 months postoperation; this study aimed to determine whether the damage would occur in a longer term. The left or right vas deferens was ligated near the epididymal head (unilateral proximal vasectomy, 12 animals) or via the inguinal canal (unilateral distal vasectomy, 11 animals) in adult male rabbits, with a sham operation being performed on the contralateral side. Six months postoperation, testes, epididymides and vasa deferentia were removed and methacrylate resin-embedded sections prepared to evaluate spermatogenesis by histological (qualitative) and stereological (quantitative) studies. The juxta-epididymal segment of the occluded vas deferens was severely distended (filled with sperm) in 10 of the 11 animals with distal vasectomy and moderately or slightly distended in nine of the 12 animals with proximal vasectomy. Severe spermatogenic damage occurred in seven animals with proximal vasectomy (the juxta-epididymal vas moderately or slightly distended), in only one animal with distal vasectomy (the vas not severely distended). In conclusion, spermatogenic damage occurred at 6 months postvasectomy in some animals, especially those with proximal vasectomy and therefore shorter occluded reproductive tract for sperm storage; the damage was probably intra-tract pressure mediated.

The prevalence of and risk factors for non-carious cervical lesions in adults in Hubei Province, China

OBJECTIVES

To describe the prevalence of non-carious cervical lesions (NCCLs) and to assess the relative affects of risk factors on NCCLs in middle-aged and elderly people in Hubei Province, China.

DESIGN

A sample of 2,160 adults, aged 35-44 years and 65-74 years and balanced by age, gender, and urbanization, participated in the cross sectional epidemiological survey. Non-carious cervical lesions were examined using a modified Tooth Wear Index. Data were collected based on structured questionnaires that assessed general information as well as oral health.

RESULTS

The prevalence of non-carious cervical lesions was 38.8% for 35-44-year-olds and 56.6% for 65-74-year-olds. The first premolars, canines, and second premolars showed the highest prevalence of lesions, while the second molars demonstrated the least. Several risk factors such as age (OR = 2.45, p < 0.001), location (OR = 1.68, p = 0.001), frequency of toothbrushing (OR = 1.33, p = 0.016), bruxism (OR = 1.37, p < 0.001), and family income (OR = 1.44, p < 0.001) were found to be associated with lesion occurrence.

CONCLUSIONS

The prevalence of non-carious cervical lesions was relatively high in the middle-aged and elderly persons in China and was also associated with socio-behavioural risk factors.

Using Ascertainment for Targeted Resequencing to Increase Power to Identify Causal Variants

Researchers continue to use genome-wide association studies (GWAS) to find the genetic markers associated with disease. Recent studies have added to the typical two-stage analysis a third stage that uses targeted resequencing on a randomly selected subset of the cases to detect the causal single-nucleotide polymorphism (SNP). We propose a design for targeted resequencing that increases the power to detect the causal variant. The design features an ascertainment scheme wherein only those cases with the presence of a risk allele are selected for targeted resequencing. We simulated a disease with a single causal SNP to evaluate our method versus a targeted resequencing design using randomly selected individuals. The simulation studies showed that ascertaining individuals for the targeted resequencing can substantially increase the power to detect a causal SNP, without increasing the false-positive rate.

Effect of alendronate on alveolar bone resorption and angiogenesis in rats with experimental periapical lesions

AIM

To investigate the effects of systemically administered alendronate, one of the most potent bisphosphonates (BPs), on alveolar bone resorption and angiogenesis in rats subjected to experimental periapical lesions over two time periods.

METHODOLOGY

Forty adult Sprague-Dawley (SD) rats were divided equally into control and experimental groups, and the pulp chambers of mandibular first molars of all rats were exposed to the oral environment to induce periapical lesions. The experimental group received daily subcutaneous injections of alendronate at a dose of 0.25 mg kg(-1), whereas the control group received only the saline vehicle. These injections were initiated 1 week before the periapical lesion induction and then continued daily throughout the entire experimental period. After 2 or 4 weeks following pulp exposure, the rats were killed, and the mandibles were examined histologically for periapical bone loss area, number of microvascular vessels (NMV) and tartrate-resistant acid phosphatase (TRAP) activity.

RESULTS

Overall, periapical bone loss area and the number of TRAP-positive cells (osteoclasts) were significantly decreased at 2 and 4 weeks, respectively, after daily subcutaneous injection of alendronate compared with the control group (P < 0.05). There was no significant decrease change in NMV (P > 0.05).

CONCLUSIONS

Administration of alendronate to rats might inhibit alveolar bone resorption associated with periapical disease, which might not lead to impairment of angiogenesis. However, because of the differences between rats and humans, one has to consider the possible consequences of this treatment in the clinic.

Significance of perihematomal edema in acute intracerebral hemorrhage: the INTERACT trial

BACKGROUND

Uncertainty surrounds the effects of cerebral edema on outcomes in intracerebral hemorrhage (ICH).

METHODS

We used data from the INTERACT trial to determine the predictors and prognostic significance of "perihematomal" edema over 72 hours after ICH. INTERACT included 404 patients with CT-confirmed ICH and elevated systolic blood pressure (BP) (150-220 mm Hg) who had the capacity to commence BP lowering treatment within 6 hours of ICH. Baseline and repeat CT (24 and 72 hours) were performed using standardized techniques, with digital images analyzed centrally. Predictors of growth in edema were determined using generalized estimating equations, and its effects on clinical outcomes were estimated using a logistic regression model.

RESULTS

Overall, 270 patients had 3 sequential CT scans available for analyses. At baseline, there was a highly significant correlation between hematoma and perihematomal edema volumes (r(2) = 0.45). Lower systolic BP and baseline hematoma volume were independently associated with absolute increase in perihematomal edema volume. History of hypertension, baseline hematoma volume, and earlier time from onset to CT were independently associated with relative increase in edema volume. Both absolute and relative increases in perihematomal edema growth were significantly associated with death or dependency at 90 days after adjustment for age, gender, and randomized treatment, but not when additionally adjusted for baseline hematoma volume.

CONCLUSIONS

The degree of, and growth in, perihematomal edema are strongly related to the size of the underlying hematoma of acute intracerebral hemorrhage, and do not appear to have a major independent effect in determining the outcome from this condition.

Six-year incidence of lower extremity arterial disease and associated risk factors in Type 1 diabetic African-Americans

AIMS

To report the 6-year incidence of, and risk factors for, lower extremity arterial disease (LEAD) in African-Americans with Type 1 diabetes mellitus.

METHODS

African-Americans (n = 483) with Type 1 diabetes were re-examined 6 years after an original visit. At both visits, patients underwent a structured clinical interview which included history of amputation or leg angioplasty because of poor circulation in lower extremities; ocular examination; masked grading of seven stereoscopic fundus photographs; and blood pressure measurements. Biological tests included blood and urine assays.

RESULTS

Of the 483 patients who had a 6-year follow-up, 457 had no LEAD at the baseline examination. Of these 457 patients, 26 (5.7%) developed LEAD over the 6-year follow-up. Six-year incidence of LEAD was significantly associated with baseline older age (P = 0.0002) and longer duration of diabetes (P < 0.0001). Multiple logistic regression analysis showed that baseline longer duration of diabetes, male gender, higher systolic blood pressure, retinopathy severity, and presence of foot ulcers were significant and independent risk factors for incidence of LEAD.

CONCLUSIONS

Blood pressure control and prevention and treatment of foot ulcers may be helpful in reducing the morbidity associated with LEAD in African-Americans with Type 1 diabetes.

The ischemic preconditioning paradox in deceased donor liver transplantation-evidence from a prospective randomized single blind clinical trial

While animal studies show that ischemic preconditioning (IPC) is beneficial in liver transplantation (LT), evidence from few smaller clinical trials is conflicting. From October 2003 to July 2006, 101 deceased donors (DD) were randomized to 10 min IPC (n = 50) or No IPC (n = 51). Primary objective was efficacy of IPC to decrease reperfusion (RP) injury. Both groups had similar donor risk index (DRI) (1.54 vs. 1.57). Aminotransferases on days 1 and 2 were significantly greater (p < 0.05) in IPC recipients. In multivariate analyses, IPC had an independent effect only on day 2 aspartate transferase. Prothrombin time, bilirubin and histological injury were similar in both groups. IPC had no significant effect on plasma TNF-alpha, IL-6 and IL-10 in the donor and TNF-alpha and IL-6 in the recipient. In contrast, IPC recipients had a significant rise in systemic IL-10 levels after RP (p < 0.05) and had fewer moderate/severe rejections within 30 days (p = 0.09). Hospital stay was similar in both groups. One-year patient and graft survival in IPC versus No IPC were 88% versus 78% (p = 0.1) and 86 versus 76% (p = 0.25), respectively. IPC increases RP injury after DDLT, an 'IPC paradox'. Other potential benefits of IPC are limited. IPC may be more effective in combination with other preconditioning regimens.

Risk factors for coronary disease and stroke in previously hospitalized African-Americans with Type 1 diabetes: a 6-year follow-up

AIMS

To report the 6-year incidence of, and risk factors for, cardiovascular disease (CVD), either coronary disease or stroke, in previously hospitalized African-Americans with Type 1 diabetes mellitus.

METHODS

African-Americans (n = 483) with Type 1 diabetes were re-examined as part of a 6-year follow-up. At both visits, patients underwent a structured clinical interview, which included history of either coronary disease or stroke, ocular examination and masked grading of seven stereoscopic fundus photographs, blood pressure measurements, and administration of the Beck Depression Inventory. Biological measurements included blood and urine assays.

RESULTS

Of the 483 patients who had a 6-year follow-up, 449 had no evidence of CVD at the baseline examination. Of these 449 patients, 51 (11.4%) developed any CVD-42 (9.3%) coronary disease and 14 (3.1%) a stroke. Six-year incidence of any CVD was significantly associated with older age (P < 0.0001) and longer duration of diabetes (P < 0.0001) at baseline. Multiple logistic regression showed that baseline older age, higher body mass index, higher diastolic blood pressure, proteinuria, retinopathy severity and being depressed were significant and independent risk factors for incidence of any CVD.

CONCLUSION

Six-year incidence of CVD is high in previously hospitalized African-Americans with Type 1 diabetes. Risk factors appear to include older age, higher body mass index, higher diastolic blood pressure, proteinuria, retinopathy severity and depression.