A Clinically Explainable AI-Based Grading System for Age-Related Macular Degeneration Using Optical Coherence Tomography

We propose an automated, explainable artificial intelligence (xAI) system for age-related macular degeneration (AMD) diagnosis. Mimicking the physician's perceptions, the proposed xAI system is capable of deriving clinically meaningful features from optical coherence tomography (OCT) B-scan images to differentiate between a normal retina, different grades of AMD (early, intermediate, geographic atrophy (GA), inactive wet or active neovascular disease [exudative or wet AMD]), and non-AMD diseases. Particularly, we extract retinal OCT-based clinical imaging markers that are correlated with the progression of AMD, which include: (i) subretinal tissue, sub-retinal pigment epithelial tissue, intraretinal fluid, subretinal fluid, and choroidal hypertransmission detection using a DeepLabV3+ network; (ii) detection of merged retina layers using a novel convolutional neural network model; (iii) drusen detection based on 2D curvature analysis; (iv) estimation of retinal layers' thickness, and first-order and higher-order reflectivity features. Those clinical features are used to grade a retinal OCT in a hierarchical decision tree process. The first step looks for severe disruption of retinal layers' indicative of advanced AMD. These cases are analyzed further to diagnose GA, inactive wet AMD, active wet AMD, and non-AMD diseases. Less severe cases are analyzed using a different pipeline to identify OCT with AMD-specific pathology, which is graded as intermediate-stage or early-stage AMD. The remainder is classified as either being a normal retina or having other non-AMD pathology. The proposed system in the multi-way classification task, evaluated on 1285 OCT images, achieved 90.82% accuracy. These promising results demonstrated the capability to automatically distinguish between normal eyes and all AMD grades in addition to non-AMD diseases.

1026 Good Prescribing Laxatives Practice for Trauma Admissions in Orthopaedic Wards at Altnagelvin Hospital

Aim

The aim of this QIP is to firstly increase percentage of T&O admissions to Orthopaedic Wards 23+25 prescribed laxatives by 25% by 1st of December over 1 month and to increase awareness among healthcare staff.

Background

Constipation in elderly during inpatient stay is common, 50% of pts>65years will develop this due to multifactorial reasons. Correct laxatives are very important to curb this predicament.

Method

These data were assessed over the following criteria, laxatives prescribed on admission, administered following prescription, monitoring bowel output, suppositories prescribed after admission. Following each week QI cycles, appropriate interventions were made to improve the adherence and data was re-measured again.

Results

From Baseline data, only 45% of patient were prescribed laxatives and only 20% patients received the medication initially. Of this group, only 20% pts had suppositories prescribed following admission. Lastly, 40% of patients had Bowel Opened (BO)>3days ago. First intervention was educating all SHOs to ensure patients received prescription on admission. Following this, mainly laxative prescription increased by 40%, and patient received their laxatives by 2% respectively in PDSA 1.

In PDSA 2, we actively ensured educating nursing staff to encourage laxative prescriptions and to inform doctors for patients with Last BO>3days ago for suppositories prescribing. Following this, laxative prescription increased to 80% while 65% pts received their prescription. Only 15% pts had BO>3days too.

Conclusion

Regular laxatives are superior to PRN & Recommended regime is Senna+Lactulose for patient adherence. Additionally, suppositories should be given as STAT rather than Prn as well.

Oral pain and infection control strategies for treating children and adolescents in India

Introduction:

Oral and dental health form an integral part of complete well being of an individual and society at large. Promoting oral health and societal progression go hand in hand.

Aim:

To investigate dentists' attitudes about pain and infection control while treating children and adolescents by assessing their recommendations of pre- and postoperative analgesics and antibiotics, and use of local anesthesia (LA) for definitive treatment in different clinical scenarios.

Materials and Method:

A total of 400 dentists, both general dental practitioners (GDPS) as well as specialist dentists, were surveyed over a period of 2 months by using a pre-tested close-ended questionnaire. The data was statistically analyzed using Pearson's Chi-square test and backward logistic regression analysis for analysis of categorical variables and independent variables, respectively. Level of significance was set at 5%.

Results:

It was found that there was a gross overuse of antibiotics and analgesics and under use of LA by GDPs compared to specialist dentists. Postoperative antibiotics and analgesics were used more commonly than preoperative antibiotics and analgesics. These strategies were used more often in permanent teeth than primary teeth except the use of LA, which was used with equal frequency in both primary as well as permanent dentition.

Conclusion:

Dependence on antibiotics and analgesics for achieving pain and infection control in children has to be minimized and focus has to be shifted on judicious definitive treatment involving use of LA, aseptic techniques, and behavior management techniques.

Effect of Sugarcane Cultivar and Foliar Insecticide Treatment on Infestations of the Invasive Sugarcane Thrips, Fulmekiola serrata (Thysanoptera: Thripidae), in Florida

Fulmekiola serrata (Kobus) was observed infesting sugarcane, Saccharum spp. hybrids, in the United States for the first time in January 2017 in Florida. Field studies were conducted to determine F. serrata infestation levels on popular sugarcane cultivars and to determine the efficacy of foliar insecticide treatments that could be used for management. Cultivar evaluations comparing six and five commercial cultivars representing >46% of the sugarcane production area in Florida were conducted in 2017 and 2018, respectively. Fulmekiola serrata infestation levels did not differ among cultivars in 2017. However, infestation levels on CP 00-1101 were greater than on CP 96-1252 grown on organic soils, and infestation levels on CP 96-1252 were greater than on CPCL 97-2730 grown on mineral soils in 2018. Three insecticide evaluations, two in 2017 and one in 2018, were conducted. The pyrethroid lambda-cyhalothrin, which is registered for use on sugarcane, was consistently associated with the greatest decreases in F. serrata infestation levels. The neonicotinoids imidacloprid and thiamethoxam, as well as the butenolide flupyradifurone, decreased infestation levels but to a lesser extent than did lambda-cyhalothrin. The spinosyn spinetoram was associated with the lowest decreases in F. serrata infestation levels. Our results supported short-term F. serrata management recommendations: Popular Florida sugarcane cultivars should be considered equally susceptible to F. serrata until additional evaluations are conducted and F. serrata outbreaks can be treated with lambda-cyhalothrin when infestations stress the crop beyond acceptable levels.

RANDOMISED, CONTROLLED, BLINDED FIELD TRIAL ON THE EFFICACY OF BIOCIDE FORMULATION (BACILLUS SPP.) IN THE CONTROL OF MOSQUITO VECTORS

A randomised, controlled, blinded field trial was conducted in a large cantonment area, to study the efficacy of the biocide formulation (Bacillus spp.) indigenously produced by Central Drug Research Institute, Lucknow, India, as a mosquito larvicide, in comparison with Fenthion and Temephos. The study revealed that the biocide formulation in dosage of 5 grams per square metre brought about a very high level of control of culicine larvae from third day of application and the effect persisted till at least 28 days (median values of percentage reduction achieved being 93% to 100%). This effect was statistically significant from 7th to 28th day, as compared to Fenthion, Temephos or the biocide in dosage of 2 grams per square metre. Fenthion, on the other hand was statistically more efficacious in bringing about a quick reduction, with a 100% reduction being obtained within a day, but the effect declined to a low level by 7th day.

Comparative evaluation of the tensile bond strength of two silicone based denture liners with denture base resins

BACKGROUND

To evaluate and compare tensile bond strength of two silicone based liners with heat cure and heat cure high impact denture base resin at baseline and after storage in artificial saliva for 30 and 60 days.

METHOD

Heat cure conventional and high impact acrylic blocks (120 blocks each) prepared with final test specimen of two blocks of each resin with a liner. The baseline samples and those tested after 30 and 60 days interval stored in artificial saliva in thermal incubator, all were pulled apart in UTM at 20 mm/min. The tensile bond strength and mode of failure (adhesive/cohesive) were assessed. Mean, SD determined and analysis using one way ANOVA and paired 't' test.

RESULTS

The highest mean tensile bond strength (1.028 MPa) and the least i.e. 0.289 MPa was observed with Permaflex silicone liner against heat cure PMMA after storage in artificial saliva at 37 ± 1 °C.

CONCLUSION

The study rejected the null hypothesis because storage time in artificial saliva affected the bond strength of the resilient liners examined. The results revealed a statistically significant difference (p < 0.05) of artificial saliva storage on the bond strength of both the liners. After storage in artificial saliva for 30 days and 60 days at 37 ± 1 °C, all the specimens showed a significant reduction in the tensile bond strength.

Determination of mesiodistal width of maxillary anterior teeth using inner canthal distance

BACKGROUND

Selection of appropriately sized maxillary anterior teeth is one of the important aspects of complete denture prosthodontics. In the past several methods have been proposed, but little consensus on an effective method for anterior teeth selection has been reached. Inner canthal distance is one of the reliable anatomic dimension that may provide a valid approach to anterior teeth selection. This study was aimed to ascertain the co-relation between inner canthal distance (ICD) and combined mesiodistal width of maxillary anterior teeth.

METHOD

This study was conducted in Army Dental Centre (R & R) Delhi Cantonment between Aug 2006 to Mar 2008. Eight hundred dentate Indian subjects of four different ethnic group; Such as Rajputs, Marathas, Sikh and Tamilian. 100 males and 100 females from each race under the age group of 18-30 years formed the subjects of study. The ICD and mesio-distal width of maxillary anteriors were measured using Digital Vernier Caliper. The Data obtained was statistically analyzed.

RESULTS

A consistent ratio of 1.61 was found between ICD and combined mesiodistal width of maxillary anteriors in all four ethnic group. The mean value showed no statistically significant difference between sex. The variation in the ratio between the ethnic groups was negligible.

CONCLUSION

The findings of the study indicated that, to select the combined mesiodistal width of maxillary anterior teeth, ICD of the required patient should be multiplied by 1.61. This ratio was consistent with all the four ethnic groups irrespective of sex.

Haematological alterations induced by oral subacute exposure to fenvalerate, nitrate and their combination in domestic buffalo, Bubalus bubalis

The present study investigated haematological alterations induced by oral subacute exposure to fenvalerate, nitrate and their combination in the domestic buffalo, Bubalus bubalis. Fenvalerate exposure produced significant declines in haemoglobin (Hb), total leukocyte count (TLC), total erythrocyte count (TEC) and mean corpuscular haemoglobin concentration (MCHC), and a corresponding elevation in mean corpuscular volume (MCV). Following oral exposure to sodium nitrate, significant declines in blood Hb, TLC, TEC, MCH and MCHC, and a significant elevation in MCV occurred. Combined exposure to fenvalerate and sodium nitrate produced severe effects with an appreciably more prominent decline in Hb, TLC, TEC and MCHC and a significant elevation in MCV. The percentage of methaemoglobin was observed to follow an elevating trend in animals exposed to sodium nitrate alone (0.69 %-13.8 %) and in combination with fenvalerate (0.75 %-13.7 %).

Evaluation of shear bond strength of composite resin bonded to alloy treated with sandblasting and electrolytic etching

Conservation of natural tooth structure precipitated the emergence of resin-retained fixed partial dentures. The weakest link in this modality is the bond between resin cement and alloy of the retainer. Various alloy surface treatment have been recommended to improve alloy-resin bond. This in vitro study was carried out to observe changes in the Nickel-Chromium alloy (Wiron 99, Bego) surface following sandblasting or electrolytic etching treatment by scanning electron microscope (SEM) and to evaluate the shear bond strength of a resin luting cement bonded to the surface treated alloy. 80 alloy blocks were cast and divided into four groups of 20 each. In groups-A & B, the test surfaces were treated by sandblasting with 50 and 250 μm sized aluminium oxide particles respectively. In groups-C & D, the test surfaces were first treated by sandblasting with 50 and 250 μm sized aluminium oxide particles respectively followed by electrolytic etching. Test surfaces were observed under SEM at 1,000× magnification. Two alloy blocks of each group were luted together by a resin luting cement (Rely X, 3M) and their shear bond strength was tested. The mean shear bond strength in MPa of groups-A to D were 6.44 (±0.74), 8.18 (±0.51), 14.45 (±0.59) and 17.43 (±1.20) respectively. Group-D showed bond strength that is more than clinically acceptable bond strength. It is recommended that before luting resin-retained fixed partial dentures, the fitting surface of the retainer should be electrolytically etched to achieve adequate micromechanical retention.

Modeling Supply Chain Performance: A Structural Equation Approach

Supply chain management (SCM) has become an effective tool now a day to survive in this competitive world. Organizations do their best to improve performance by adopting better supply chain (SC) performance indicators. In this paper 19 key performance indicators (KPI) were identified based on strong literature support in consultation of practitioners and consultants in the field of non-livestock retailing (NLR). NLR is the retailing of agriculture and horticulture products. The technique of factor analysis using principal component analysis with Varimax rotation has classified KPI into four factors as; inventory metrics, customer metrics, flexibility metrics and growth and learning metrics. Structural Equation Modelling (SEM) approach was used to develop and validate a model for measuring SC performance of organized NLR industry based on KPI. The data for analysis was collected from top 10 organized NLR players operating in Punjab, Chandigarh, New Delhi and Gurgaon in India. The results were subjected to rigorous statistical tests for reliability and validity. Finally, these classified KPI were presented in the form of a model to measure SC performance of organized NLR industry using SEM.

Evaluation of Four Elastomeric Interocclusal Recording Materials

BACKGROUND

The fabrication of dental prosthesis requires the transfer of interocclusal records from patient's mouth to semi-adjustable articulators using different kinds of recording media. Any inaccuracy in these interocclusal records leads to occlusal errors in the final prosthesis. This study was conducted to evaluate the dimensional changes occurring in the interocclusal recording material over a given period of time and the material's resistance to compression during the cast mounting on the articulator.

METHODS

In this in vitro study, the linear dimensional change and compressive resistance of four commercially available elastomeric interocclusal recording media was tested. Three were addition silicones and the fourth was a polyether material. Cylindrical samples of 10mm diameter of each material were prepared in three different thicknesses of 2, 4 and 6mm. Ten samples each of thickness of 2, 4 and 6mm for all four materials were prepared (total of 120 samples). The linear dimensional changes of the samples were evaluated after 24 hours of fabrication. The compressive resistance was measured when each of these was subjected to a constant compressive load of 25 Newtons.

RESULTS

The mean linear dimensional change in a horizontal plane was minimum for Kanibite Hard, an addition silicone. Ramitec showed the maximum linear dimensional change. The mean compression distance was least for Futar D Occlusion (an addition silicone) and maximum for Ramitec (a polyether). It was observed that the samples of thickness 2mm for all the materials underwent least compression.

CONCLUSION

The compressive resistance of each elastomer was inversely proportional to the thickness of the sample. This implies that minimum thickness of the recording materials should be used for recording maxillomandibular relations without sacrificing the strength of the interocclusal record.

Toxic impacts of cypermethrin on behavior and histology of certain tissues of albino rats

In the present investigation, the behavioral, morphological, and histopathological effects of cypermethrin, a widely used synthetic pyrethroid insecticide, was ascertained in male and female albino rats (Rattus norvegicus). Cypermethrin administered at repeated oral doses of 5 and 20 mg/kg/day for 30 days produced varying degree of mild to moderate toxic symptoms and behavioral changes in both male and female rats. The lower dose produced very mild toxicosis characterized by intermittent diarrhea, decreased feed intake, and thick eye discharge, whereas higher dose displayed mild to moderate toxicosis with diarrhea, decreased feed intake, loss of body weight, dyspnoea, ataxia, eye discharge, and salivation. Two female and one male albino rats died between 23 to 28 days after displaying signs of incoordination and tremors. Repeated oral doses of cypermethrin for 30 days enhanced the relative weight of liver and heart, but significantly decreased that of brain, kidneys, and testes. Microscopically, cypermethrin produced neuronal degeneration and increase in glial cells in brain, and disorganization of hepatic laminae, increase in sinusoid, and necrosis of hepatocytes in liver. Section of kidney displayed hemorrhage and sloughing off renal epithelial cell in the convoluted tubules, shrinkage of glomeruli, and necrosis of renal tubules. Repeated administration of cypermethrin also produced hemorrhages within myocardium, disruption of branching structure, and loss of striation of cardiac tissue; thickening of alveolar septa in lungs, partial to extensive loss of various stages of spermatogenesis in testes, and loss of follicular cells and oocytes in ovaries. The study suggested that repeated oral exposure of cypermethrin has considerable harmful effects on body organs in R. norvegicus.

Clinicopathological Studies on Vitamin D(3) Toxicity and Therapeutic Evaluation of Aloe vera in Rats

A study was conducted to examine the clinical signs, hematological, biochemical and histopathological changes in vitamin D₃ toxicity at a dose rate 2 mg/kg b.wt. of vitamin D₃ and to assess the protective effect of Aloe vera in vitamin D₃ toxicity. The clinical signs observed were anorexia, progressive weight loss, difficulty in movement and respiration, diarrhea, epistaxis, subnormal body temperature and nervous signs before death. Mortality was observed in treated rats between day 10 and day 19 of treatment. The gross postmortem changes observed were severe emaciation, white chalky deposits on epicardial surface of heart, pin point white deposits on cortical surface of kidneys with pale yellow discoloration and diffused white deposits on serosal surface of stomach and intestine with bloody ingesta in lumen. The hematological changes included non-significant increase in hemoglobin and total leukocyte count and significant increase in relative neutrophil count. The biochemical changes observed were significant increase in plasma concentration of calcium, phosphorus and blood urea nitrogen, whereas a significant decrease in the concentration of albumin and total plasma protein was observed. The histopathological lesions included calcification of various organs, viz., tongue, stomach, intestines, kidney, heart, aorta, larynx, trachea, lungs, spleen, choroid plexus arteries of brain and vas deferens. The Aloe vera juice (2.5% in drinking water) has no protective effect on vitamin D₃ toxicity (2 mg/kg b.wt.).

A Case of Intranasal Hemangioma and Concurrent Tetracycline-induced Ulcerative Gastritis in Dogs

Incidence of drug-induced gastritis and ulceration in human medicine is well established. Besides, unilateral hemangioma, a unique concurrent case of tetracycline induced gastric toxicity in a dog, characterized by gastritis and ulceration is being reported here. Grossly, the appearance of gastric ulcers mimicked the appearance of Italian pizza. Histological examination further supported drug-induced etiology in this case. This is probably the one of the few cases in the annals of veterinary medicine to be documented as drug-induced gastric toxicity in dog.

Neuropathological studies of chickens following exposure to chlorpyrifos

The objective of this study was to determine the putative neuropathological effects in young chickens after administration of a single dose of 55 mg/kg bw chlorpyrifos. The gross lesions of the nervous system comprised of congestions in the brain. Microscopic examination of brain showed mild congestion of cerebral blood vessels and mild perivascular cuffing of lymphomononuclear cells in the cerebral cortex and necrosis of the neurons. The interesting findings were the presence of cytoplasmic vacuolations of cerebral neurons and swelling of the endothelial cell of the cerebral capillaries. Cerebellum showed congestion and hemorrhages in the granular layer and necrosis of Purkinje cell. Sciatic nerve exhibited mild edema, swelling and degeneration of axons, and swelling of Schwann cells. There was a significant inhibition of plasma cholinesterase enzyme activity in chickens administered with chlorpyrifos compared to chickens of control group. The study revealed that administration of chlorpyrifos produces neuropathological lesions in chickens shortly after exposure.

In vivo changes in antioxidant system and protective role of selenium in chlorpyrifos-induced subchronic toxicity in bubalus bubalis

Chlorpyrifos, an organophosphate, is one of the widely used insecticides for control of pests in various agricultural and animal husbandry operations. The objective of the present investigation was to assess the effect of subchronic exposure of chlorpyrifos on the antioxidant status of buffalo calves and to perceive the role of selenium in cases of chlorpyrifos toxicity. Chlorpyrifos at a dose rate of 0.05mg/kg per day for 20 consecutive weeks, significantly elevated the enzymic activity of glutathione peroxidase (GPx) (54.8%), glutathione reductase (GR) (79.4%), glutathione-S-transferase (GST) (34.2%), glucose-6-phosphate dehydrogenase (G6PD) (33.2%), superoxide dismutase (SOD) (19.3%) and catalase (CAT) (63.8%). The altered antioxidant status was well evident from the depleting glutathione levels and a two-fold rise in the extent of lipid peroxidation. Supplementation of selenium in the form of sodium selenite @ 0.05mg/kg per day for 20 weeks in chlorpyrifos intoxicated calves had a marked beneficial effect on the overall antioxidant potential of the animals as evident by no significant alteration in the extent of lipid peroxidation, levels of blood glutathione and activities of various antioxidant enzymes viz. GST, GR, SOD, CAT and G6PD. There was only a significant increase in the activity of GPx to the tune of 27.4%. Therefore, on the basis of the present investigation it can be suggested that oxidative stress is one of the main mechanism involved in chlorpyrifos toxicity and supplementation with sodium selenite in such cases can have significant beneficial and therapeutic effects.

Plasma Concentrations, Pharmacokinetics and Urinary Excretion of Gatifloxacin after Single Intravenous Injection in Buffalo Calves

The pharmacokinetics and urinary excretion of gatifloxacin were investigated after a single intravenous injection of 4 mg/kg body weight in buffalo calves. The therapeutic plasma drug concentration was maintained for up to 12 h. Gatifloxacin rapidly distributed from blood to tissue compartments, which was evident from the high values of the distribution rate constant, alpha1 (11.1 +/- 1.06 h(-1)) and the rate constant of transfer of drug from central to peripheral compartment, k12 (6.29 +/- 0.46 h(-1)). The area under the plasma drug concentration-time curve and apparent volume of distribution were 17.1 +/- 0.63 (microg.h)/ml and 3.56 +/- 0.95 L/kg, respectively. The elimination half-life (t (1/2 beta)), total body clearance (ClB) and the ratio of drug present in tissues and plasma (T/P) were 10.4 +/- 2.47 h, 235.1 +/- 8.47 ml/(kg.h) and 10.1 +/- 2.25, respectively. About 19.7% of the administered drug was excreted in urine within 24 h. A satisfactory intravenous dosage regimen for gatifloxacin in buffalo calves would be 5.3 mg/kg at 24 h intervals.

Gabapentin in the treatment of fibromyalgia: A randomized, double-blind, placebo-controlled, multicenter trial

OBJECTIVE

To assess the efficacy and safety of gabapentin in patients with fibromyalgia.

METHODS

A 12-week, randomized, double-blind study was designed to compare gabapentin (1,200-2,400 mg/day) (n=75 patients) with placebo (n=75 patients) for efficacy and safety in treating pain associated with fibromyalgia. The primary outcome measure was the Brief Pain Inventory (BPI) average pain severity score (range 0-10, where 0=no pain and 10=pain as bad as you can imagine). Response to treatment was defined as a reduction of >or=30% in this score. The primary analysis of efficacy for continuous variables was a longitudinal analysis of the intent-to-treat sample, with treatment-by-time interaction as the measure of effect.

RESULTS

Gabapentin-treated patients displayed a significantly greater improvement in the BPI average pain severity score (P=0.015; estimated difference between groups at week 12=-0.92 [95% confidence interval -1.75, -0.71]). A significantly greater proportion of gabapentin-treated patients compared with placebo-treated patients achieved response at end point (51% versus 31%; P=0.014). Gabapentin compared with placebo also significantly improved the BPI average pain interference score, the Fibromyalgia Impact Questionnaire total score, the Clinical Global Impression of Severity, the Patient Global Impression of Improvement, the Medical Outcomes Study (MOS) Sleep Problems Index, and the MOS Short Form 36 vitality score, but not the mean tender point pain threshold or the Montgomery Asberg Depression Rating Scale. Gabapentin was generally well tolerated.

CONCLUSION

Gabapentin (1,200-2,400 mg/day) is safe and efficacious for the treatment of pain and other symptoms associated with fibromyalgia.

A placebo-controlled multi-centred evaluation of an anaesthetic gel (Oraqix) for periodontal therapy

AIMS

Six Canadian dental schools investigated the ability of a thermosetting gel containing 25 mg/g prilocaine and 25 mg/g lidocaine as active agents to produce analgesia in periodontal pockets utilizing a randomized, double-blind, placebo-controlled study.

MATERIALS AND METHODS

The study consisted of 130 patients, each of whom received the active or placebo gel in periodontal pockets in one quadrant of the mouth for 30 s prior to periodontal debridement (scaling and root planing). Pain was measured using both a 100-mm Visual Analogue Scale (VAS) and a Verbal Rating Scale (VRS).

RESULTS

The median VAS pain score for the patients treated with the anaesthetic gel was 5 mm (range 0-85 mm) as opposed to 13 mm (range 0-79 mm) in the placebo-treated patients (P=0.015). There was no significant difference in the percentage of patients reporting no or mild pain (78% and 76% for the anaesthetic gel and placebo, respectively). No significant differences were seen in patient demographics, or mandible versus maxilla.

CONCLUSIONS

The VAS pain scores showed that the anaesthetic gel 5% was statistically more effective than the placebo in reducing pain during periodontal debridement.

Predictors of functional outcome in elderly patients undergoing posterior lumbar spine surgery

To ascertain the predictors of functional outcome in elderly patients undergoing posterior lumbar spinal decompression and fusion, a modified low back outcome score questionnaire survey in 83 elderly patients (49 men, 34 women) was carried out at our hospital. The average follow-up was 35.8 months (range: 22-57 months). The outcomes were as follows: excellent to good, 83%; fair, 7%; and poor, 10%. Multiple regression analysis revealed that significant predictors of unfavorable outcome included coexistence of other bone and joint degenerative disorders (p < 0.001) and history of heart disease (p < 0.01). Patients who had undergone previous lumbar surgery had significantly lower modified low back outcome score than those without previous lumbar spine surgery (p < 0.05). The modified low back outcome score questionnaire system is a reliable method in elderly patients.

Demineralized bone matrix, bone morphogenetic proteins, and animal models of spine fusion: an overview

Preclinical investigations on the use of bone morphogenetic proteins (BMP) in the spine have yielded promising results. This has led to the preliminary introduction of these growth factors in controlled clinical trials. Initial data made available suggest that these differentiating factors will play a major role in the treatment of spinal disorders in the future. This article reviews key preclinical studies and their results that formed the basis for introduction into clinical trials. Non-primate and non-human primate models of spine fusion with BMP are reviewed objectively, and important issues regarding carrier, dose, and site of implantation are discussed. Finally, exciting new gene therapy research is discussed, with comments made on its applicability for the future.

Sudden sensorineural hearing loss after spinal surgery under general anesthesia

Two patients, ages 72 and 71, who underwent lumbar decompressive surgery for spinal stenosis, were evaluated for postoperative sudden sensorineural hearing loss (SSHL). After two uncomplicated spinal procedures, both patients developed SSHL immediately after surgery. Hearing loss was moderate to profound in these two patients. None of the patients had a significant otologic history. Nitrous oxide administration, Valsalva maneuvers during general anesthesia, and transient drops in cerebrospinal fluid pressure stemming from spinal decompression may, in some combination, lead to an implosive force on the inner ear, causing SSHL. Further causes of postlumbar surgery SSHL may include microemboli or viral infections. SSHL is a rare but possible complication after nonotologic, noncardiac bypass surgery; only 26 cases of SSHL after this surgery have been reported. We encourage the continued reporting of sudden sensorineural hearing loss after spinal surgery.

A practical guide to tobacco cessation in dental offices

Tobacco use is an important risk factor for advanced periodontitis, poor response to periodontal therapy, oral neoplasms, and dental implant failure. Given the effect of tobacco use on oral health, the dental office may be an ideal place for tobacco cessation intervention, especially since a large proportion of smokers visit their dentist on a regular basis. This paper reviews various tobacco cessation strategies for the dental office and provides practical information on assessing patients' readiness to quit and choosing appropriate tobacco cessation interventions.

Proactive management of air quality

Traditional air resource management systems have difficulty in addressing global issues, sustainable development, direct citizen participation, and integration with broad economic interests. As reactive management systems, they tend to be compliance-driven, static, and rigid. In contrast, proactive management systems are principle-driven, innovative, and flexible. Bridge scientists play a key role in supporting the transformation of raw data into wise action. Decision-makers need to integrate social values with knowledge about emissions, atmospheric processes, and potential environmental effects using the primary tools of measurements, monitoring, and modeling. The Alberta Clean Air Strategic Alliance, a unique partnership of governments, industry, and public interest groups formed in 1994, operates a comprehensive air management system that is capable of addressing air issues of greater complexity and uncertainty. Its success is measured by the satisfaction of its diverse stakeholders and by the number and scope of its initiatives.

Correlation between vertebral body rotation and two-dimensional vertebral bone density measurement

The aim of this study was to determine the effect of vertebral rotation, as seen in idiopathic scoliosis, on bone mineral density determination for the lumbar spine. Bone mineral content, biplanar vertebral segment area and calculated bone mineral density of each vertebra from L1 to L4 were obtained for a human cadaveric specimen. The average density for the entire L1-L4 segment was also recorded. This was done with the spine in the midline position as well as in rotation up to a maximum of 60 degrees either side of the midline. The spine was rotated in each direction using 10 degrees increments and two bone density readings were done at each rotation interval. The measured biplanar vertebral segment area increased with increasing rotation from 0 degrees to 50 degrees but decreased after 50 degrees of rotation (r = 0.73, p<0.001). The bone mineral density was significantly negatively correlated with the degree of rotation (r = -0.92, p<0.001). The decrease in measured bone mineral density was nearly 20% when the lumbar spine was rotated from neutral to 60 . This study demonstrates that degree of spinal rotation influences apparent bone mineral density by increasing the apparent vertebral segment area. The measurement change may be as high as 20%. This fact should be considered when investigating scoliotic patients with vertebral segment rotation.

Hydroxyurea-induced hypersensitivity pneumonitis: A case report and literature review

Hydroxyurea is a cytotoxic agent indicated in the treatment of a variety of malignant and nonmalignant conditions. Apart from dose-related bone marrow suppression, this antineoplastic agent is generally well tolerated. This report describes a patient with chronic myeloid leukemia who developed severe pneumonitis within four weeks of beginning therapy with hydroxyurea. Pathological examination of a lung specimen obtained by video-assisted thoracoscopic lung biopsy revealed extensive active alveolar and interstitial inflammation, and poorly formed granulomas. After the cessation of hydroxyurea and treatment with systemic corticosteroids, both clinical and radiological resolution of pneumonitis occurred. Physicians using hydroxyurea must be aware of its potentially life-threatening pulmonary toxicity.

Incidental durotomy in spine surgery

STUDY DESIGN

Retrospective review of a large series of patients who underwent spinal surgery at a single institution during a 10-year period.

OBJECTIVES

To further clarify the frequency of incidental durotomy during spine surgery, its treatment, associated complications, and results of long-term clinical follow-up.

SUMMARY OF BACKGROUND DATA

Incidental durotomy is a relatively common occurrence during spinal surgery. There remains significant concern about it despite reports of good associated clinical outcomes. There have been few large clinical series on the subject.

METHODS

A retrospective review was conducted of clinical and surgical records and radiographic data for consecutive patients who underwent spinal surgery performed by the two senior surgeons from January 1989 through December 1998.

RESULTS

A total of 2144 patients were reviewed, and 74 were found to have dural tears occurring during or before surgery. Incidental durotomy occurred at the time of surgery in 66 patients (3.1% overall incidence). Incidence varied according to the specific procedure performed but was highest in the group that underwent revision surgery. The incidence of clinically significant durotomies occurring during surgery but not identified at the time was 0.28%. All dural tears that occurred during surgery and were recognized (60 of 66) were repaired primarily. Pseudomeningoceles developed in five of the remaining six patients. All six patients had subsequent surgical repair of dural defects because of failure of conservative therapy. A mean follow-up of 22.4 months was available and showed good long-term clinical results for all patients.

CONCLUSIONS

Incidental durotomy, if recognized and treated appropriately, does not lead to long-term sequelae.

Association between findings of provocative discography and vertebral endplate signal changes as seen on MRI

Provocative discography is a controversial diagnostic tool for pathologic discs. Modic has identified vertebral endplate signal changes on magnetic resonance imaging (MRI) that are thought to signify advanced discogenic degeneration. These two distinct diagnostic tools are examined to determine if there is association between them. Fifty-three consecutive patients who underwent both investigations were retrospectively reviewed. In discs that had negative T1 MRI findings, 28.2% of patients had concordant pain and 17.3% had discordant pain. In discs with positive T1 MRI findings, 34.8% of patients had concordant pain and 17.4% had discordant pain. 79.5% and 74.4% of levels with patient concordant pain on discography had no endplate changes on T1- and T2 weighted MR images, respectively (compared with 84.5% and 81.7%, respectively, for levels with no patient pain on discography). Our data showed no significant relationship between these distinct diagnostic tools. Further investigation of their relative roles in this application is recommended.

Gene therapy for spine fusion

Gene therapy is a novel therapeutic modality for repair and regeneration of musculoskeletal tissues, including the spine. Various methods for therapeutic gene transfer are presented in this article. Several studies in which gene transfer has been used specifically to enhance spine fusion in animal models are reviewed.

Current concepts in intervertebral disc restoration

A current focus of treatment for degenerative disk disease is the restoration of the intervertebral disk. This article summarizes the structure and function of the intervertebral disk, the pathogenesis of its degeneration, and the clinical relevance of degenerative disk disease. Current literature relating to intervertebral disk replacement and regeneration is reviewed.

Surgical options in the management of residual foot problems in poliomyelitis

Although poliomyelitis is not encountered in the Western countries, it is still endemic in the underdeveloped world. Because the foot commonly is involved, an understanding of the causative factors and the available options of treatment is essential before surgical intervention. It is important to note that inadequate or improper surgical procedures potentially can lead to more disability; a well-planned approach to the foot problem, after considering the patient as a whole and understanding the principles involved, is the best option.

The use of rhBMP-2 in interbody fusion cages. Definitive evidence of osteoinduction in humans: a preliminary report

STUDY DESIGN

A prospective randomized controlled human clinical pilot trial.

OBJECTIVES

To determine the feasibility of using rhBMP-2/collagen as a substitute for autogenous bone graft inside interbody fusion cages to achieve arthrodesis in humans.

SUMMARY OF BACKGROUND DATA

Preclinical studies have shown rhBMP-2 to be an effective substitute for autogenous bone graft, but there are no studies to date documenting such efficacy for human spine fusion.

METHODS

Fourteen patients with single-level lumbar degenerative disc disease refractory to nonoperative management were randomized to receive lumbar interbody arthrodesis with a tapered cylindrical threaded fusion cage filled with rhBMP-2/collagen sponge or autogenous iliac crest bone. Patients were evaluated with radiographs, sagittally reformatted computed tomography scans, and Short Form-36 and Oswestry outcome questionnaires.

RESULTS

All 11 patients who received rhBMP-2 were judged by three independent radiologists to have solid fusions (at 6, 12, and 24 months postimplantation), whereas only 2 of the 3 control patients, who received the standard treatment of autogenous iliac crest bone, were deemed to be fused. The Oswestry Disability Questionnaire scores of the rhBMP-2 group improved sooner (after 3 months) than those of the autograft group, with both groups demonstrating similar improvement at 6 months. Short Form 36 scores continued to improve up to 24 months.

CONCLUSION

The arthrodesis was found to occur more reliably in patients treated with rhBMP-2-filled fusion cages than in controls treated with autogenous bone graft, although the sample size was limited. There were no adverse events related to the rhBMP-2 treatment. This study is one of the first to show consistent and unequivocal osteoinduction by a recombinant growth factor in-humans.

Anterior lumbar interbody fusion with osteoinductive growth factors

Anterior intervertebral fusion increasingly is used as a treatment for discogenic or intersegmental pathologic diseases of the lumbar spine. This is in part attributable to the evolution and refinement of laparoscopic and minimally invasive surgical techniques that now can be used to access the anterior spinal column. It also is attributable to the availability of newer generation intervertebral fixation devices such as the threaded titanium cages or threaded allograft bone dowels, both of which are technically simpler to implant. Recently, limited clinical studies of intervertebral lumbar fusion have examined the use of these devices combined with osteoinductive growth factors as substitutes for autogenous bone graft. Early clinical results of lumbar fusion using threaded intervertebral implants filled with recombinant human bone morphogenetic protein-2 have been favorable. Higher fusion rates, shorter operative times, and shorter hospital stays have been reported in the initial series. Clinical trials involving larger cohorts with various spinal applications for osteoinductive molecules currently are in progress.

Bone grafting for spinal fusion

At least 250,000 spinal fusions are performed in the United States each year, nearly all requiring implantation of bone graft material. The preferred technique for most of these operations is the transplantation of structured or morcellized autologous corticocancellous bone from the iliac crest. Further, because of the increasing frequency of spinal fusion surgery during the 1990s, arthrodesis of the spine has become the most common reason for autologous bone graft harvest. This article reviews the current clinical status of autogenous bone grafts and alternative materials in spinal fusion surgery.

The placement of lumbar pedicle screws using computerised stereotactic guidance

Computer-assisted frameless stereotactic image guidance allows precise preoperative planning and intraoperative localisation of the image. It has been developed and tested in the laboratory.

We evaluated the efficacy, clinical results and complications of placement of a pedicle screw in the lumbar spine using this technique. A total of 62 patients (28 men, 34 women) had lumbar decompression and spinal fusion with segmental pedicle screws. Postoperative CT scans were taken of 35 patients to investigate the placement of 330 screws. None showed penetration of the medial or inferior wall of a pedicle. Registration was carried out 66 times. The number of fiducial points used on each registration averaged 5.8 (4 to 7) The mean registration error was 0.75 mm (0.32 to 1.72).

This technique provides a safe and reliable guide for placement of transpedicular screws in the lumbar spine.

The placement of lumbar pedicle screws using computerised stereotactic guidance

Computer-assisted frameless stereotactic image guidance allows precise preoperative planning and intraoperative localisation of the image. It has been developed and tested in the laboratory. We evaluated the efficacy, clinical results and complications of placement of a pedicle screw in the lumbar spine using this technique. A total of 62 patients (28 men, 34 women) had lumbar decompression and spinal fusion with segmental pedicle screws. Postoperative CT scans were taken of 35 patients to investigate the placement of 330 screws. None showed penetration of the medial or inferior wall of a pedicle. Registration was carried out 66 times. The number of fiducial points used on each registration averaged 5.8 (4 to 7) The mean registration error was 0.75 mm (0.32 to 1.72). This technique provides a safe and reliable guide for placement of transpedicular screws in the lumbar spine.

Cervical flexion and extension radiographs in acutely injured patients

Flexion and extension lateral radiographs of the cervical spine may suggest signs of ligamentous and soft tissue injuries in a potentially unstable spine. However, patients with acute injuries and severe pain and muscle spasms may not be able to move their necks effectively, severely compromising the diagnostic yield of the radiographs. In addition, there are reports of serious neurologic injuries occurring with the use of these radiographs in acutely injured patients. The purpose of this study was to determine the effectiveness and yield of obtaining cervical spine flexion and extension radiographs in the emergency department on acutely injured patients. Review of all patients with cervical flexion and extension radiographs presenting to a Level 1 trauma center was performed. All radiographs were judged based on the adequacy of flexion and extension movement and positive findings indicative of instability by the radiologist in the emergency room. The radiographs of one patient (0.34%) revealed positive findings of instability. Of the 290 flexion and extension radiographs, 97 (33.5%) of them showed such little or inadequate flexion or extension movement that cervical stability could not be assessed. Flexion and extension cervical radiographs should not be obtained routinely in the emergency department because 1/3 of these studies will be inadequate because of pain and muscle spasms experienced by patients. Patients with cervical injuries may not be able to fully flex and extend their necks; this may lead to false reassurance to patients who actually have had an inadequate study to diagnose potential instability.