Resilient liner vs. clip attachment effect on peri‐implant tissues of bar‐implant‐retained mandibular overdenture: a 1‐year clinical and radiographical study

Purpose: The aim of this study was to compare between the effects of resilient liner and clip attachments of bar‐implant‐retained mandibular overdenture on peri‐implant tissues. Materials and methods: In a randomized‐controlled clinical trial, 30 edentulous male patients (mean age 62.5 years) were equally assigned to two groups. In each patient, two implants were inserted in the canine area of the mandible using a two‐stage surgical protocol. After 3 months, the implants were connected with resilient bars. Mandibular overdentures were retained to the bars with either clips (group I) or silicone‐resilient liners (group II). Peri‐implant tissues were evaluated clinically (with regard to plaque scores, gingival scores and probing depths) and radiographically (with regard to peri‐implant vertical and horizontal alveolar bone changes). Evaluations were performed at the time of overdenture insertion (T0), 6 months (T6) and 12 months (T12) after overdenture insertion. Results: After 12 months of using bar‐implant‐retained mandibular overdenture, the resilient liner attachment had significantly decreased peri‐implant plaque score, gingival score, probing depth, vertical and horizontal bone loss when compared with the clip attachment. Conclusion: Within the limitations of this study, and in terms of peri‐implant tissue health of bar‐implant‐retained mandibular overdenture, we recommend resilient liner rather than clip attachment. To cite this article:
Elsyad MA, EL Shoukouki AH. Resilient liner vs. clip attachment effect on peri‐implant tissues of bar‐implant‐retained mandibular overdenture: a 1‐year clinical and radiographical study.
Clin. Oral Impl. Res. 21 , 2010; 473–480
doi: 10.1111/j.1600‐0501.2009.01879.x     

Reduced bleeding events with subcutaneous administration of recombinant human factor IX in immune-tolerant hemophilia B dogs

Intravenous administration of recombinant human factor IX (rhFIX) acutely corrects the coagulopathy in hemophilia B dogs. To date, 20 of 20 dogs developed inhibitory antibodies to the xenoprotein, making it impossible to determine if new human FIX products, formulations, or methods of chronic administration can reduce bleeding frequency. Our goal was to determine whether hemophilia B dogs rendered tolerant to rhFIX would have reduced bleeding episodes while on sustained prophylactic rhFIX administered subcutaneously. Reproducible methods were developed for inducing tolerance to rhFIX in this strain of hemophilia B dogs, resulting in a significant reduction in the development of inhibitors relative to historical controls (5 of 12 versus 20 or 20, P <.001). The 7 of 12 tolerized hemophilia B dogs exhibited shortened whole blood clotting times (WBCTs), sustained detectable FIX antigen, undetectable Bethesda inhibitors, transient or no detectable antihuman FIX antibody titers by enzyme-linked immunosorbent assay (ELISA), and normal clearance of infused rhFIX. Tolerized hemophilia B dogs had 69% reduction in bleeding frequency in year 1 compared with nontolerized hemophilia B dogs (P =.0007). If proven safe in human clinical trials, subcutaneous rhFIX may provide an alternate approach to prophylactic therapy in selected patients with hemophilia B.     

Further delineation of the KBG syndrome caused by ANKRD11 aberrations

Loss-of-function variants in ANKRD11 were identified as the cause of KBG syndrome, an autosomal dominant syndrome with specific dental, neurobehavioural, craniofacial and skeletal anomalies. We present the largest cohort of KBG syndrome cases confirmed by ANKRD11 variants reported so far, consisting of 20 patients from 13 families. Sixteen patients were molecularly diagnosed by Sanger sequencing of ANKRD11, one familial case and three sporadic patients were diagnosed through whole-exome sequencing and one patient was identified through genomewide array analysis. All patients were evaluated by a clinical geneticist. Detailed orofacial phenotyping, including orthodontic evaluation, intra-oral photographs and orthopantomograms, was performed in 10 patients and revealed besides the hallmark feature of macrodontia of central upper incisors, several additional dental anomalies as oligodontia, talon cusps and macrodontia of other teeth. Three-dimensional (3D) stereophotogrammetry was performed in 14 patients and 3D analysis of patients compared with controls showed consistent facial dysmorphisms comprising a bulbous nasal tip, upturned nose with a broad base and a round or triangular face. Many patients exhibited neurobehavioural problems, such as autism spectrum disorder or hyperactivity. One-third of patients presented with (conductive) hearing loss. Congenital heart defects, velopharyngeal insufficiency and hip anomalies were less frequent. On the basis of our observations, we recommend cardiac assessment in children and regular hearing tests in all individuals with a molecular diagnosis of KBG syndrome. As ANKRD11 is a relatively common gene in which sequence variants have been identified in individuals with neurodevelopmental disorders, it seems an important contributor to the aetiology of both sporadic and familial cases.     

Reflex anal dilatation: effect of parting the buttocks on anal function in normal subjects and patients with anorectal and spinal disease.

Anal dilatation in response to gentle parting of the buttocks has been advocated as a sign of sexual abuse in children, but nothing is known of the physiology of this response or its existence in normal subjects, in patients with spinal disease, and in patients with a weak sphincter and whether it can be elicited after training. To answer these questions we investigated the effect of parting the buttocks on anal function. Combined anal manometry and electromyography was conducted in six normal subjects (five men, one woman, aged 19-53 years), in 18 patients with faecal incontinence (three men, 15 women, aged 30-80 years), and in seven paraplegic patients (six men, one woman, aged 25-36 years), in four of whom the posterior sacral roots had been cut. Parting the buttocks in normal subjects reduced the pressure in the anal canal from 102 (20) to 14 (3) cm H2O (mean (SEM), p less than 0.00001), but did not cause the anus to gape. This drop in pressure was associated with increased electrical activity in the external anal sphincter. Normal subjects could consciously relax the external anal sphincter and reduce the anal pressure but not so as to result in anal gaping during traction on the buttocks, even after anal dilatation. Stimulation of the anal lining by moving a probe in and out of the anal canal increased the activity of the external anal sphincter, raising anal pressures. Paraplegic patients who had lost conscious control of their external sphincters showed anal gaping when the buttocks were parted. A similar phenomenon was seen in patients with faecal incontinence who had weakness of the external anal sphincter, while incontinent patients with weakness of both sphincters showed anal gaping even at rest. Inasmuch as the results of our study can be applied to children, the data suggest that reflex anal dilatation should only be used to support a diagnosis of sexual abuse if sphincter function is otherwise normal and there is no evidence of cerebrospinal disease. Although our results do not support the notion that children could become so conditioned to repeated digital or penile penetration of the anus that they can cause the anus to gape when the buttocks are parted, neither do they exclude it.     

Atenolol offers better protection than clonidine against cardiac injury in kainic acid-induced status epilepticus

Background and Purpose

Status epilepticus is increasingly associated with cardiac injury in both clinical and animal studies. The current study examined ECG activity for up to 48 h following kainic acid (KA) seizure induction and compared the potential of atenolol and clonidine to attenuate this cardiac pathology.

Experimental Approach

Sprague-Dawley rats (male, 300–350 g) were implanted with ECG and electrocorticogram electrodes to allow simultaneous telemetric recordings of cardiac and cortical responses during and after KA-induced seizures. Animals were randomized into saline controls, and saline vehicle-, clonidine- or atenolol-pretreated KA groups.

Key Results

KA administration in the saline-pretreated group produced an immediate bradycardic response (maximal decrease of 28 ± 6%), coinciding with low-level seizure activity. As high-level seizure behaviours and EEG spiking increased, tachycardia also developed, with a maximum heart rate increase of 38 ± 7% coinciding with QTc prolongation and T wave elevation. Both clonidine and atenolol pretreatment attenuated seizure activity and reduced KA-induced changes in heart rate, QTc interval and T wave amplitude observed during both bradycardic and tachycardic phases in saline-pretreated KA animals. Clonidine, however, failed to reduce the power of EEG frequencies. Atenolol and to a lesser extent clonidine attenuated the cardiac hypercontraction band necrosis, inflammatory infiltration, and oedema at 48 h after KA, relative to the saline-KA group.

Conclusions and Implications

Severe seizure activity in this model was clearly associated with altered ECG activity and cardiac pathology. We suggest that modulation of sympathetic activity by atenolol provides a promising cardioprotective approach in status epilepticus.     

Is the transit time of a meal through the small intestine related to the rate at which it leaves the stomach?

Using non-invasive techniques, we investigated how varying the size or composition of a meal altered the rate at which it passed through the stomach and small intestine in normal volunteers. Increasing the size of the meal by doubling the absorbable components delayed gastric emptying, did not significantly influence the time taken for the head of the meal to reach the caecum, but retarded the entry of the bulk of the meal residues into the caecum. Incorporating fat in the meal slowed gastric emptying, but did not significantly affect small bowel transit time. The addition of the unabsorbable disaccharide lactulose (in place of an equivalent amount of sucrose) accelerated small bowel transit time, but did not significantly influence gastric emptying. Thus, our results indicated that changes in small bowel transit time could occur independently of changes in gastric emptying in normal healthy subjects.     

Percutaneous injuries among health care workers. The real value of human immunodeficiency virus testing of 'donor' blood

A decision analysis was conducted to examine whether health care workers should receive short-term (42 days) zidovudine treatment following percutaneous exposure to blood, as well as to determine the value of testing "donor" (patient's) blood. Three alternative options were analyzed: treat all, treat none, and test. In the treat all option, all health care workers receive short-term zidovudine therapy immediately after exposure; in the treat none option, no one receives zidovudine; and in the test option, donor blood is tested, and if it is human immunodeficiency virus (HIV) positive, zidovudine is given. Baseline variables were obtained from the literature. Each outcome was expressed as a utility; this is a method of quantifying the values that persons place on different health states. The results showed that the test option was preferred. Sensitivity analyses indicated that even if the risk of seroconversion were zero or the effectiveness of zidovudine were zero or the drug were withheld, this option was preferred, thus indicating some value of testing other than merely identifying health care workers who should receive zidovudine. In the baseline analysis, this was derived from the fact that approximately 95% of the health care workers would be reassured by a negative test; ie, only approximately 5% of donors are HIV positive. If the prevalence of HIV seropositivity exceeded 42%, the treat none option was preferred. This was found to be due to the fact that increased numbers of health care workers would be told that they were exposed to HIV-positive blood. The "worrying factor" associated with such an exposure was such that above 42% HIV seropositivity, the treat none option was preferred overall. Thus, the real value of testing donor blood is in identifying those persons (greater than 95%) who could be told that they were exposed to HIV-negative blood, that is, reducing their worrying factor to zero. Because acquired immunodeficiency syndrome is a fatal disease, and given that zidovudine is the only available therapeutic option at present, the drug has an important role to play if its effectiveness is greater than zero.     

Estrogen represses whereas the estrogen-antagonist ICI 182780 stimulates placental CRH gene expression

CRH and estrogens, produced by placental trophoblasts, have been suggested to play pivotal roles in the control of human parturition. Estrogen has been shown to affect hypothalamic CRH expression. Therefore, we evaluated 17 beta-estradiol (E2) in the regulation of CRH gene expression in placental cells. E2 inhibited CRH mRNA expression in a dose-dependent manner, which paralleled the decrease in CRH protein levels in culture media. A complete estrogen receptor (ER) antagonist, ICI 182780, not only blocked repression of CRH mRNA levels by E2, but up-regulated CRH mRNA and protein synthesis. An ER alpha-mixed agonist/antagonist and ER beta antagonist, 4-hydroxytamoxifen, also down-regulated CRH gene expression. Using quantitative RT-PCR, we found that placental trophoblasts express predominantly the ER alpha form of the receptor. Transient transfection assays conducted in the choriocarcinoma cell line JEG-3 demonstrated that E2 repressed CRH promoter activity, whereas the antagonist ICI 182780 up-regulated CRH promoter activity when ER alpha was cotransfected. These studies demonstrate that E2 represses placental CRH gene expression through an ER alpha-mediated mechanism. Estrogen may therefore modulate placental CRH production, influencing the rate of rise of maternal plasma CRH concentrations and potentially the length of gestation.     

Oral prostaglandin (PGE2) therapy for chronic viral hepatitis B and C

The cytoprotective effects of prostaglandins have been utilized in the prevention of hepatitis B virus reactivation after liver transplantation. This pilot study evaluated the effects of oral prostaglandin E₂ (PGE₂) in chronic viral hepatitis B and C. Twenty patients with chronic hepatitis B and 20 patients with chronic hepatitis C received 4mgday^–1 PGE₂ for 6 months. The lymphocyte antiviral enzyme 2',5'-oligoadenylate synthetase (2',5'-OAS) and peripheral blood monocyte procoagulant activity (PCA) were measured before, during and after the treatment. Three of 20 hepatitis B and five of 20 hepatitis C patients withdrew from the study. Eight of 17 hepatitis B patients responded: in seven of these eight patients, serum alanine aminotransferase (ALT) levels normalized; loss of viral replication was sustained in all eight patients; and seroconversion from hepatitis Be antigen (HBeAg) to hepatitis Be antibody (HBeAb) positivity occurred in seven patients over the 48-week duration of this study. In 14 of the 15 hepatitis C patients, hepatitis C virus (HCV) RNA remained detectable and the serum ALT levels remained elevated. 2',5'-OAS levels and PCA values did not correlate with other markers of response to PGE₂ therapy in either chronic hepatitis B or C. In summary, PGE₂ was associated with sustained loss of viral replication in 47% of chronic hepatitis B patients; no beneficial effects were apparent in chronic hepatitis C.