Comparison between three-dimensional and standard miniplates in the management of mandibular angle fractures: a prospective, randomized, double-blind, controlled clinical study.

The aim of this study was to compare the clinical and radiological outcomes of mandibular angle fractures (MAFs) managed with three-dimensional (3D) miniplates and standard miniplates (according to Champy's principles). A prospective, randomized, controlled clinical study was carried out on 20 patients with MAFs, divided into two groups. Group A patients were treated with a single 1-mm 3D titanium miniplate; group B patients were treated with a single 2.0-mm standard titanium miniplate. Patients were followed for 6 months for infection, wound dehiscence, segmental mobility, malocclusion, mouth opening, hardware failure, hardware palpability, paraesthesia, and malunion/non-union. A densitometry analysis was performed using DIGORA software on digital panoramic radiographs to evaluate bone healing. Six complications occurred, representing a total rate of 30%. Three complications occurred in group A and three in group B, with identical complication rates of 30%. No major difference in terms of the radiographic assessment was observed between the two systems. The 3D curved strut plate is an effective treatment modality for the management of MAFs, with a complication rate comparable to that found with the standard miniplate. This trial is registered at ClinicalTrials.gov, number NCT01939015.

A systematic review and meta-analysis of the clinical outcomes for various surgical modalities in the management of temporomandibular joint ankylosis.

A systematic review and meta-analysis was performed to assess the clinical outcomes of the following four methods for the management of temporomandibular joint (TMJ) ankylosis: gap arthroplasty (GA), interpositional gap arthroplasty (IPG) using the temporalis muscle, reconstruction of the TMJ using a costochondral graft (CCG), and alloplastic joint reconstruction (AJR) of the TMJ. A comprehensive electronic and manual search of the literature without date or language restriction was performed in December 2013 to identify randomized controlled trials, controlled clinical trials (CCTs), and retrospective studies with the aim of comparing the four surgical modalities for TMJ ankylosis. Sixteen publications were included: seven were CCTs and nine were retrospective. A significant difference was found between GA and IPG in maximal inter-incisal opening (MIO) and recurrence rate (P = 0.04 and P = 0.02, respectively). A significant difference was found between IPG and CCG reconstruction in MIO (P = 0.01), but no significant difference with regard to the recurrence rate (P = 0.71). There was a significant difference between costochondral joint (CCJ) and AJR for MIO and pain (P = 0.04 and P = 0.03, respectively). The results of the meta-analysis showed that IPG results in a significant improvement in MIO and lower recurrence rate when compared to GA. Also, IPG shows a greater improvement in MIO and comparable recurrence rate when compared to CCG reconstruction. GA and CCG reconstruction have a comparable recurrence rate. Lastly, CCJ provides greater MIO when compared to AJR, whereas AJR is superior to CCJ in reducing pain.

Three-dimensional versus standard miniplate fixation in the management of mandibular angle fractures: a systematic review and meta-analysis.

The aim of the present study was to test whether there is a significant difference in the clinical outcomes between standard and three-dimensional (3D) miniplate fixation in the management of mandibular angle fractures (MAFs). An electronic search without date and language restrictions was performed in October 2013. Inclusion criteria were studies in humans including randomized controlled trials, controlled clinical trials, and retrospective studies, with the aim of comparing the two techniques. Six studies were included. The meta-analyses revealed statistically significant differences for the incidence of hardware failure and postoperative trismus. There were no significant differences in the incidence of postoperative infection, malocclusion, wound dehiscence, non-union/malunion, or paresthesia. The cumulative odds ratio was 0.42, meaning that the use of 3D miniplates in the fixation of MAFs decreases the risk of the event (postoperative complication) by 58%. The results of this meta-analysis showed lower postoperative complication rates with the use of 3D miniplate fixation in comparison with the use of standard miniplate fixation in the management of MAFs.

Increase in neuronal nitric oxide synthase content of the gastroduodenal tract of diabetic rats.

This study examined the changes occurring in the pattern of distribution and expression of neuronal nitric oxide synthase (nNOS)-positive nerves in the gastroduodenal tract of streptozotocin-induced diabetic rats. The ganglion cells of the myenteric plexus of the gastric antrum of normal rats contain nNOS. We also observed nNOS-positive neurons and fibres in the myenteric plexus of the duodenum of normal rats. After the onset of diabetes, the number and intensity of staining of nNOS-positive nerve profiles in the gastric antrum and duodenum did not change significantly. However, Western blotting showed a significant increase in the expression of nNOS after the onset of diabetes. In conclusion, diabetes of 4 and 32 weeks duration induced an increase in the tissue content of nNOS in the gastroduodenum of rat. The increase in the level of nNOS in the gastroduodenum of diabetic rats may explain why impaired gastric emptying is common in patients with diabetes.

L-arginine stimulates insulin secretion from the pancreas of normal and diabetic rats.

Several reports have shown that nitric oxide (NO) stimulates glucose-induced insulin secretion in the pancreas of normal rat but the effect of L-arginine (a NO donor) on insulin secretion from the pancreas of diabetic pancreas is unknown. Fragments of pancreatic tissue from normal and diabetic rats were incubated for 45 min in Krebs solution containing 100mM L-arginine. The supernatant was subsequently analyzed for the insulin content using radioimmunoassay technique. L-arginine evoked large increases in insulin secretion from the pancreas of diabetic rat. The insulin secreted from the pancreas of diabetic rat was numerically but not significantly lower compared to that of normal rat pancreas. In conclusion, L-arginine, a nitric oxide donor stimulates insulin secretion from the pancreas of diabetic rats.

Comparison of the inhibitory effects of cromakalim and pinacidil (potassium channel openers) with those of oxybutynin on stimulated guinea pig and rabbit detrusor muscle strips.

To compare the inhibitory effects of a new group of smooth muscle relaxants, the potassium channel openers cromakalim and pinacidil, with those of oxybutynin on detrusor muscle stimulation in animals. Detrusor strips of guinea pigs (n=16) and rabbits (n=20) were mounted in organ bath for recording of isometric tension. Alpha,beta-methylene ATP (10(-7), 10(-6), 10(-5) M), carbachol (10(-6), 10(-5), 3 x 10(-5), 5 x 10(-5) M) and transmural electrical-field stimulation (TES) were applied and concentration-response curves in the absence or presence of cromakalim (10(-6), 10(-5) M), pinacidil (10(-5), 5 x 10(-5) M) and oxybutynin (10(-5), 5 x 10(-5) M) were generated. All curves were displaced to the right in a concentration-dependent manner. The order of potency of inhibition was as follows: alpha,beta-methylene ATP (pinacidil>oxybutynin>cromakalim in guinea pigs; pinacidil>cromakalim>oxybutynin in rabbits); TES (pinacidil>cromakalim>oxybutynin in guinea pigs; cromakalim>oxybutynin>pinacidil in rabbits); carbachol (oxybutynin>pinacidil>cromakalim in guinea pigs; oxybutynin>cromakalim>pinacidil in rabbits). Cromakalim and pinacidil mainly inhibited purinergic-induced (alpha,beta-methylene ATP and TES) detrusor contractions.

Diabetes mellitus is associated with a decrease in vasoactive intestinal polypeptide content of gastrointestinal tract of rat.

Vasoactive intestinal polypeptide (VIP) is an inhibitory non-adrenergic, non-cholinergic transmitter, which mediate in the relaxation of sphincters of the gastrointestinal tract. The aim of this study was to determine whether there is a change in the pattern of innervation and tissue content of VIP in the rat gastroduodenum after the onset of streptozotocin (STZ)-induced diabetes mellitus. Diabetes was induced by a single intraperitoneal injection of STZ (60 mg Kg(-1)). Four weeks after the induction of diabetes mellitus, the rats were anaethetised and the pancreata were removed for further processing. VIP was localized and measured in normal and diabetic rat gastroduodenal tissues by immunohistochemistry and radioimmunoassay, respectively. VIP immunoreactivity was stronger in the ganglion cells of the submucosal and myenteric plexuses of the gastric antrum and duodenum of normal rats (n = 6) when compared to that of diabetic rats (n = 6). Moreover, the number of VIP-positive neurons was significantly lower in the gastrointestinal tract of diabetic rats compared to normal. The VIP content of the gastric antrum and duodenum of diabetic rat was significantly lower (p< 0.05) than that of normal rat. In contrast to the lower tissue levels of VIP in the gastroduodenal segment of diabetic rats, the plasma level of VIP was significantly higher (p< 0.04) in diabetic rat compared to normal. The plasma level of VIP in normal rats was comparable to that measured in normal human beings. A low tissue level of VIP in the gastroduodenal tract of diabetic rat may contribute in part to the abnormal gut motility observed in diabetic patients.

Disturbances in the propagation of the slow wave during acute local ischaemia in the feline small intestine.

OBJECTIVE AND DESIGN: The normal aborad propagation of the slow wave in the small intestine is easily distorted by pacing, hypoxia or transection. We studied whether acute local ischaemia would also induce serious conduction disturbances and ectopic pacemaking. METHODS: After general anaesthesia and a mid-abdominal incision, a multi-electrode array of 240 extracellular electrodes was positioned on the serosal surface of an exteriorized intestinal loop. Simultaneous recordings of all 240 surface electrodes was performed during a control period and for 5-10 min following local acute arterial occlusion. After the experiments activation maps were constructed describing the pattern of propagation of the slow waves. RESULTS: During control periods, the activation maps showed homogeneous aborad conduction of the slow wave. During acute ischaemia, local areas of inexcitability developed rapidly, merging together to form lines of conduction block. This in turn often provoked the appearance of subsidiary ectopic pacemakers. The location of the conduction blocks as well as that of ectopic pacemakers was highly variable and could disappear and reappear at other sites. CONCLUSION: Within minutes, acute ischaemia disturbed the organized homogeneous aborad propagation of the slow wave leading to pronounced inhomogeneous depression of conduction, local inexcitability, conduction block and the appearance of subsidiary pacemakers.

Flow cytometric cell cycle kinetics and quantitative measurement of c-erbB-2 and mutant p53 proteins in normal, hyperplastic, and malignant endometrial biopsies.

OBJECTIVES: The purpose of this study is to biologically characterize endometrial hyperplasia by investigating changes in DNA ploidy pattern, the expression of c-erbB-2 p185 and mutant p53 proteins. METHODS AND RESULTS: Our results show that all normal endometria (n = 62) were exclusively diploid and 2 (2.5%) of 79 endometrial hyperplasias and 22 (68.8%) of 32 endometrial carcinomas were aneuploid. Upper 95% normal values for synthetic phase fraction (SPF), c-erbB-2 and p53 were applied as cut-off values to discriminate between normal and malignant endometria. When 9%, 3.2 HNU (Human Neu Unit)/microgram protein, and 0.39 ng/mg protein were used as cut-off values for SPF. c-erbB-2, and p53 respectively, 13.9%, 20.2%, and 0% of endometrial hyperplasia and 50%, 56.3%, and 12.5% of endometrial carcinoma showed raised levels of the corresponding parameters. CONCLUSIONS: Our results indicate that subsets of endometrial hyperplasia are biologically different as evidenced by the presence of DNA aneuploidy, high SPF and c-erbB-2 overexpression, which may provide biological markers for assessing progression to endometrial carcinoma.

Wave mapping: detection of co-existing multiple wavefronts in high-resolution electrical mapping.

High-resolution mapping makes it possible to reconstruct and display the conduction pattern of the action potential as it propagates through cardiac or smooth muscles. During slow and regular activity, time mapping of the spread of activation muscles. During slow and regular activity, time mapping of the spread of activation is relatively simple and straightforward. However, when frequencies are high or conduction is slow, such as seen during atrial fibrillation or found in the pregnant uterus, the tracking of individual waves may become more difficult and uncertain. In order to reconstruct the pathway of a single wave, a search and sorting routine was developed which makes it possible to distinguish, track and display individual wavelets. The algorithm is able to detect variations in conduction block, spontaneous shifts in the location of the pacemaker and changes in the direction of conduction. It is less sensitive when two or more wavefronts intermingle in space and time, such as during collision or fusion. Wave mapping is especially useful, in addition to current time mapping, in sorting quickly through the large amount of data produced by high-resolution mapping of electrical activities in cardiac and smooth muscle.

Comparative study between different diagnostic techniques in huge splenomegaly cases in El-Minia Province.

Fifty four patients presenting by huge splenomegaly were admitted to Tropical Medicine Department, El-Minia University Hospital. Tissue biopsy revealed pure bilharziasis due to S. hematobium in 10 (19%) cases, liver cirrhosis in 23 (42%), mixed schistosomiasis and cirrhosis in 8 (15%), hepatoma in 3 (6%), lymphoma in 6 (11%) and hematological diseases in the form of chronic myeloid leukemia in 2 (3.5%) and thalassemia major in 2 (3.5%) cases. The sensitivity and specificity of abdominal ultrasonography was 100% and 97% in cases of schistosomiasis, 100% and 100% in cases of hepatoma, 87% and 100% in cases of liver cirrhosis, 33% and 100% in cases of lymphoma respectively. There was a positive significant correlation between endoscopic variceal grading, portal vein diameter, splenic vein diameter, size of the spleen and the grading of the portal tract thickenings. The pathological and ultrasonographic diagnosis was the same in 38 (70%) cases. Splenogram was characteristic but not diagnostic in cases of schistosomiasis and liver cirrhosis. It was diagnostic and similar to peripheral blood picture in the 2 cases of chronic myeloid leukemia and was normal in cases of thalassemia major. Splenic aspiration was able to diagnose all cases of lymphomas. It can be considered as a useful adjunct to the usual diagnostic procedures, both in staging and follow up, especially in cases presenting only by splenomegaly.

Micropapillary variant of transitional cell carcinoma of the urinary bladder. Histologic pattern resembling ovarian papillary serous carcinoma.

Eighteen cases of transitional cell carcinoma (TCC) of the urinary bladder containing a micropapillary component (MPC) (> 90%, three cases; 50-90%, nine cases; < 50%, six cases) are presented. The patients' mean age was 66.6 years (range, 47-81 years) with a male predominance (male-to-female ratio of 5:1). The MPC was part of the surface noninvasive TCC in 16 cases and part of the invasive portion of the TCC in all 18 cases. Eight patients had metastases, each with a predominant (> or = 50%) MPC in the metastases; local recurrence was documented in one case, and the tumor was locally invasive into pelvic structures in three cases. Histologically, the surface MPC comprised slender, delicate filiform processes or small papillary clusters of tumor cells, whereas the deep MPC was composed of infiltrating tight clusters of micropapillary aggregates that were often present within lacunae. Vascular-lymphatic invasion was consistently present in the micropapillary areas. The cytologic features of the MPC were those of grade 3 TCC. A concurrent TCC in situ was identified in 10 cases, noninvasive papillary TCC component in all cases, and glandular differentiation of the invasive TCC in five cases. The initial stage at presentation was usually high stage: one patient with stage A, nine with stage B, six with stage C, and two with stage D. Follow-up data (mean, 44.8 months; range, 6-96 months) indicated that four patients were alive with disease, seven patients were dead of disease, and there was no evidence of disease in seven patients. In five cases, DNA ploidy analyzed by static image analysis showed nondiploid indices within the micropapillary TCC component, and in three cases the DNA index of the MPC (noninvasive, invasive, or at metastatic site) exceeded the DNA index of the noninvasive papillary TCC. In conclusion, the presence of a MPC in TCC is associated with high-grade and high-stage TCC with a tendency to vascular invasion. Our data suggest that a surface MPC in bladder biopsy specimens is a poor prognostic histologic feature and, if the biopsy does not contain muscularis propria, deeper biopsies should be recommended to determine the presence of muscle invasion.

Spatial and temporal variations in local spike propagation in the myometrium of the 17-day pregnant rat.

Detailed spatial analysis of propagation of individual action potential was performed during spontaneous bursts of activity in the isolated 17-day pregnant rat myometrium. Use was made of high-resolution mapping with simultaneous recordings from 240 extracellular electrodes. Positioning of the electrode assembly by itself did not have any adverse effects, and no differences were found in the period or duration of spontaneous bursts recorded with and without the electrode assembly touching the tissue. The spread of propagation of individual action potentials was reconstructed at several moments during myometrial spike bursts. Both the direction and the sequence of activation of the myometrium were found to be highly variable and depended on 1) the level and spatial dispersion of excitability and 2) whether conduction occurred predominantly in the longitudinal or the circumferential direction. Furthermore, conduction was frequently complicated by the spontaneous occurrence of 1) lines of conduction block, 2) focal sites of pacemaking, or 3) merging of two or more wavelets into a single wave. In contrast, when the myometrium was divided into small segments, activity became much more regular, and both the location of the pacemaker and the direction of propagation were much more stable than in the whole myometrium. In conclusion, spontaneous spatial variations in local spike propagation at the preterm stage could provide for the necessary asynchrony in activation and play a role in the prevention of forceful contractions and premature labor.

Multielectrode mapping of slow-wave activity in the isolated rabbit duodenum.

The technique of multiple simultaneous recordings from a large number of extracellular electrodes (> 100) is currently used in the study of normal and abnormal electrical conduction in the heart and the genesis of cardiac arrhythmias. To investigate whether such a system could also be applied in gastrointestinal electrophysiology, several studies were performed with this technique on segments of isolated rabbit duodenum. A multiple-electrode assembly consisting of 240 silver wires was positioned on the serosal surface of the duodenum, and the recorded signals were, after suitable processing, stored. Thereafter, analysis of all simultaneously recorded slow waves during a selected period of time was performed to reconstruct the pattern of conduction in the duodenum. The first results show that there is a considerable variation in conduction pattern, which is determined by the site of the natural pacemaker. Several experiments were performed to rule out possible deleterious effects of positioning the multiple-electrode assembly on the duodenum. Furthermore, prolonged periods of recording did not influence propagation speed and pattern provided that the positioning of the multiple electrode assembly was performed with care. Entrainment of the natural pacemaker was possible by applying electrical stimuli through 2 of the 240 extracellular electrodes during simultaneous recordings. In conclusion, multisite extracellular mapping of gastrointestinal smooth muscle is possible and can be used to study origin and spread of slow-wave activity.

Hemodynamic and catecholamine responses to laryngoscopy with vs. without endotracheal intubation.

To study the relationship between the intensity of the stimulus exerted against the base of the tongue during direct laryngoscopy and the magnitude of associated hemodynamic and catecholamine responses, a study was conducted in 40 ASA I or II patients. Laryngoscopy lasting 40 s was performed with a size 3 Macintosh blade connected to a force-displacement transducer. The intensity of the stimulus exerted during laryngoscopy is expressed by the product of its average force (N) and duration (s) and given as impulse in Ns. Highly significant relationships were found between the impulse during laryngoscopy and the maximal hemodynamic and catecholamine responses. Also, when laryngoscopy was followed by orotracheal intubation, significant relationships were found with steeper slopes of the regression lines for systolic blood pressure, heart rate and plasma epinephrine concentrations. A more rapid regression of hemodynamic data was seen in intubated patients, whereas their plasma catecholamine concentrations regressed more slowly. The mechanisms of the responses to laryngoscopy and orotracheal intubation are proposed to be by somato-visceral reflexes. Stimulation of proprioceptors at the base of the tongue during laryngoscopy induces impulse-dependent increases of systemic blood pressure, heart rate and plasma catecholamine concentrations. Subsequent orotracheal intubation recruits additional receptors that elicit augmented hemodynamic and epinephrine responses as well as some vagal inhibition of the heart.

Vascular effects of some opioid receptor agonists.

Opioid peptides have been implicated in shock-associated hypotension. Our aim was to find out whether opioid agonists have direct vasodilator actions on vascular smooth muscle. The study was conducted on rat abdominal aortic rings. In rings precontracted with either norepinephrine, prostaglandin F2 alpha, or high potassium Krebs (HPK), the effects of the opioid agonists tested (morphine, U50488H, ethylketocyclazocine (EKC), and bremazocine) depended on the precontracting agent used. HPK-precontracted rings were relaxed by all agonists tested. In norepinephrine-precontracted rings, all caused contraction at low concentrations and relaxation at high concentrations except bremazocine, which caused only relaxation. In prostaglandin F2 alpha-precontracted rings, U50488H produced contraction at low concentrations and relaxation at high concentrations while EKC caused only relaxation and morphine or bremazocine caused only contraction. All relaxant responses were endothelium-independent and were antagonized by verapamil but not by a number of antagonists including naloxone. MR2266, propranolol, diphenhydramine, cimetidine, and indomethacin. They may reflect calcium channel blockade. Morphine-induced vasoconstriction was antagonized by high concentrations of of naloxone or mepyramine and may be due to release of histamine by a naloxone-sensitive mechanism. We conclude that (a) the opioid agonists tested exert direct actions on vascular smooth muscle; (b) the nature of the response depended not only on the agonist used and its concentration but also on the agent used to precontract the tissue; and (c) it is unlikely that direct actions of endogenous opioids contribute to the shock-associated hypotension because high doses were needed to elicit them.

Electrical basis of excitation and inhibition of human colonic smooth muscle.

Excitation and inhibition of electrical activities of the musculature of the human colon and the consequent changes in motor activities were studied in vitro. The mechanisms of excitation and inhibition were very different from those of the small intestine and colons from animal models. Carbachol increased spiking activity and the frequency of bursts of electrical oscillations in longitudinal muscle. Each longitudinal muscle contraction was related to a burst of electrical oscillations. Carbachol induced one of three patterns of activity in circular muscle: (a) continuous electrical oscillatory activity (14-24 cpm) with spikes, associated with tonic contraction; (b) bursts of such electrical activity, associated with broad phasic contractions; or (c) prolonged membrane potential depolarizations (frequency 1-3 cpm) with superimposed intense spiking activity, associated with phasic contractions. Isoproterenol inhibited all electrical and mechanical activities in both muscle layers. These results may provide a better understanding of (a) the origins of the variable patterns of electrical and motor activities and (b) the relationship between electrical and mechanical activities of the human colon musculature.

Vagal control of canine postprandial upper gastrointestinal motility.

The role of the vagus nerves in the control of postprandial motility in the upper gastrointestinal tract was investigated in four dogs by use of a bilateral cervical cooling blockade technique. On administration of food, the fasting migrating motor complex (MMC) was replaced by the postprandial (feeding) pattern. Feeding pattern duration varied in a dose-dependent manner with either total volume or calories of food. During the feeding pattern, oscillations in lower esophageal sphincter (LES) pressure occurred at time intervals equivalent to the MMC cycle period. Twenty-one control feeding experiments and 17 postprandial vagal blockade experiments were performed, with a minimum of three of each type in each dog. Vagal blockade, initiated at times ranging from 15 min to 4 h after feeding and maintained for up to 5 h, abolished the postprandial activity in the upper gastrointestinal tract. During postprandial vagal blockade, LES pressure was abolished and bursts of contractions were observed only in the upper small bowel, a pattern resembling that observed during vagal blockade in the fasted state. These bursts occurred at the expected times relative to, and their cycle period was not significantly different from, that of the MMCs recorded prior to feeding. Vagal blockade started prior to feeding prevented initiation of the fed pattern, which appeared immediately on termination of the blockade. We conclude that initiation and maintenance of the postprandial pattern in the upper gastrointestinal tract with concurrent inhibition of the fasting MMC normally require vagal integrity. The "clock" controlling the MMC cycle period is not reset by feeding, but its effect on motility is suppressed.

The Ehlers-Danlos syndrome and colonic perforation. Report of a case and physiologic assessment of underlying motility disorder.

The Ehlers-Danlos syndrome is a genetically determined disorder of connective tissue which is generally known for its features of fragile, hyperextensible skin, hypermobile joints, and tissue fragility. Less commonly, colorectal complications can occur, including bleeding, prolapse, and diverticulitis. A rare case of colonic perforation associated with Ehlers-Danlos syndrome is presented. Additionally, in vitro electromyographic studies of the colonic tissue were performed which suggested a possible link between abnormal myogenic activity and the colonic perforations. The authors recommend that treatment be either a permanent colostomy or a subtotal colectomy with anastomosis to the rectum for similar cases.