Value-based healthcare analysis of shoulder surgery for patients with symptomatic rotator cuff tears - Calculating the impact of arthroscopic cuff repair

BACKGROUND

Surgical repair of full-thickness rotator cuff tears in symptomatic patients is known to offer significant benefits. Despite this there remains a lack of universal appreciation that such surgery offers high clinical value, with some commissioners even limiting access to it. The value-based healthcare agenda provides a means to design, deliver and measure the impact of healthcare to a defined segment of patients. The aim of this study was to measure the value of surgically repairing primary symptomatic full-thickness rotator cuff tears when outcomes and costs were assessed over an entire care pathway.

METHODS

A prospective study of patients undergoing rotator cuff tears repair was undertaken. Patients were managed using a standardised integrated care pathway. Subsequent outcomes and costs were measured over the whole care pathway. Outcomes were assessed from both traditional and patient centric re-formatted prisms.

RESULTS

Significant improvement in clinical outcomes where recognised when assessed from either the traditional or re-formatted prisms. Economic review of this approach revealed the pathway generated a sustainable and notable positive margin.

DISCUSSION

This study evidences how a well-designed value-based healthcare shoulder approach can be delivered and measured. It demonstrates rotator cuff surgery to be a high value treatment for patients with symptomatic rotator cuff tears.

Impact of intravenous tranexamic acid on patients undergoing shoulder arthroplasty surgery

Background

Shoulder arthroplasty surgery carries the risk of blood loss. The antifibrinolytic tranexamic acid (TXA) is effective in reducing blood loss in lower limb arthroplasty. The purpose of this study was to assess blood loss and associated complications following shoulder arthroplasty performed with and without TXA for both elective and trauma indications.

Methods

A cohort study was performed to assess blood loss, transfusion requirements and post-operative venous thromboembolic events (VTE) following shoulder arthroplasty undertaken with and without the use of intravenous TXA.

Results

The study consisted of 67 patients (n = 36 with TXA; n = 31 without TXA). Type of arthroplasty included reverse-shoulder arthroplasty, total-shoulder arthroplasty and hemiarthroplasty. There was no significant difference between TXA and non-TXA groups regarding blood loss (TXA group haemoglobin drop 20.6 mg/dL; non-TXA group haemoglobin drop 20.5 mg/dL; p = 0.978). There was no significant difference in measured outcomes with or without TXA use for elective or trauma indications, nor regarding type of arthroplasty.

Discussion

The use of intravenous TXA in shoulder arthroplasty was not associated with a significant reduction in blood loss or post-operative transfusion rates, nor did it impact on VTE. This result was not affected by the indication being elective or trauma nor the type of arthroplasty surgery performed.

257 The Effect of the COVID-19 Pandemic on Mental Health Associated Trauma, Admissions and Fractures at a London Major Trauma Centre

Aim

Non-injury related factors have been extensively studied in major trauma and shown to have a significant impact on patient outcomes, with mental illness and associated medication use proven to have a negative effect on bone health and fracture healing. We report the epidemiological effect of COVID-19 pandemic on mental health associated Orthopaedic trauma, fractures, and admissions to our centre.

Method

We collated data retrospectively from the electronic records of Orthopaedic inpatients in an 8-week non-COVID and COVID period analysing demographic data, referral and admission numbers, orthopaedic injuries, surgery performed and patient co-morbidities including psychiatric history.

Results

here were 824 Orthopaedic referrals and 358 admissions (6/day) in the non-COVID period with 38/358 (10.6%) admissions having a psychiatric diagnosis and 30/358 (8.4%) also having a fracture. This was compared to 473 referrals and 195 admissions (3/day) in the COVID period with 73/195 (37.4%) admissions having a documented psychiatric diagnosis and 47/195 (24.1%) a fracture. 22/38 (57.9%) and 52/73 (71.2%) patients were known to mental health services, respectively.

Conclusions

Whilst total numbers utilising the Orthopaedic service decreased, the impact of the pandemic and lockdown disproportionately affected those with mental health problems, a group already at higher risk of poorer functional outcomes and non-union. The proportion of patients with both a fracture and a psychiatric diagnosis more than doubled and the number of patients presenting due to a traumatic suicide attempt almost tripled. It is imperative that adequate support is in place for vulnerable mental health patients, particularly as we are currently experiencing the “second wave” of COVID-19.

The 2021 Magnonics Roadmap

Magnonics is a budding research field in nanomagnetism and nanoscience that addresses the use of spin waves (magnons) to transmit, store, and process information. The rapid advancements of this field during last one decade in terms of upsurge in research papers, review articles, citations, proposals of devices as well as introduction of new sub-topics prompted us to present the first roadmap on magnonics. This is a collection of 22 sections written by leading experts in this field who review and discuss the current status besides presenting their vision of future perspectives. Today, the principal challenges in applied magnonics are the excitation of sub-100 nm wavelength magnons, their manipulation on the nanoscale and the creation of sub-micrometre devices using low-Gilbert damping magnetic materials and its interconnections to standard electronics. To this end, magnonics offers lower energy consumption, easier integrability and compatibility with CMOS structure, reprogrammability, shorter wavelength, smaller device features, anisotropic properties, negative group velocity, non-reciprocity and efficient tunability by various external stimuli to name a few. Hence, despite being a young research field, magnonics has come a long way since its early inception. This roadmap asserts a milestone for future emerging research directions in magnonics, and hopefully, it will inspire a series of exciting new articles on the same topic in the coming years.

The effect of the COVID-19 pandemic on mental health associated trauma, admissions and fractures at a London major trauma centre

INTRODUCTION

Non-injury-related factors have been extensively studied in major trauma and have been shown to have a significant impact on patient outcomes. Mental illness and associated medication use has been proven to have a negative effect on bone health and fracture healing.

MATERIALS AND METHODS

We collated data retrospectively from the records of orthopaedic inpatients in a non-COVID and COVID period. We analysed demographic data, referral and admission numbers, orthopaedic injuries, surgery performed and patient comorbidities, including psychiatric history.

RESULTS

There were 824 orthopaedic referrals and 358 admissions (six/day) in the non-COVID period, with 38/358 (10.6%) admissions having a psychiatric diagnosis and 30/358 (8.4%) also having a fracture. This was compared with 473 referrals and 195 admissions (three/day) in the COVID period, with 73/195 (37.4%) admissions having a documented psychiatric diagnosis and 47/195 (24.1%) having a fracture.

DISCUSSION

There was a reduction in the number of admissions and referrals during the pandemic, but a simultaneous three-fold rise in admissions with a psychiatric diagnosis. The proportion of patients with both a fracture and a psychiatric diagnosis more than doubled and the number of patients presenting due to a traumatic suicide attempt almost tripled.

CONCLUSION

While total numbers using the orthopaedic service decreased, the impact of the pandemic and lockdown disproportionately affects those with mental health problems, a group already at higher risk of poorer functional outcomes and non-union. It is imperative that adequate support is in place for patients with vulnerable mental health during these periods, particularly as we look towards a potential 'second wave' of COVID-19.

All-optical detection of interfacial spin transparency from spin pumping in β-Ta/CoFeB thin films

Generation and utilization of pure spin current have revolutionized energy-efficient spintronic devices. Spin pumping effect generates pure spin current, and for its increased efficiency, spin-mixing conductance and interfacial spin transparency are imperative. The plethora of reports available on generation of spin current with giant magnitude overlook the interfacial spin transparency. Here, we investigate spin pumping in β-Ta/CoFeB thin films by an all-optical time-resolved magneto-optical Kerr effect technique. From variation of Gilbert damping with Ta and CoFeB thicknesses, we extract the spin diffusion length of β-Ta and spin-mixing conductances. Consequently, interfacial spin transparency is derived as 0.50 ± 0.03 from the spin Hall magnetoresistance model for the β-Ta/CoFeB interface. Furthermore, invariance of Gilbert damping with Cu spacer layer thickness inserted between β-Ta and CoFeB layers confirms the absence of other interface effects including spin memory loss. This demonstrates a reliable and noninvasive way to determine interfacial spin transparency and signifies its role in generation of pure spin current by spin pumping effect.

Dental Restorative Materials Based on Thiol-Michael Photopolymerization

Step-growth thiol-Michael photopolymerizable resins, constituting an alternative chemistry to the current methacrylate-based chain-growth polymerizations, were developed and evaluated for use as dental restorative materials. The beneficial features inherent to anion-mediated thiol-Michael polymerizations were explored, such as rapid photocuring, low stress generation, ester content tunability, and improved mechanical performance in a moist environment. An ester-free tetrafunctional thiol and a ultraviolet-sensitive photobase generator were implemented to facilitate thiol-Michael photopolymerization. Thiol-Michael resins of varied ester content were fabricated under suitable light activation. Polymerization kinetics and shrinkage stress were determined with Fourier-transform infrared spectroscopy coupled with tensometery measurements. Thermomechanical properties of new materials were evaluated by dynamic mechanical analysis and in 3-point bending stress-strain experiments. Photopolymerization kinetics, polymerization shrinkage stress, glass transition temperature, flexural modulus, flexural toughness, and water sorption/solubility were compared between different thiol-Michael systems and the BisGMA/TEGDMA control. Furthermore, the mechanical performance of 2 thiol-Michael composites and a control composite were compared before and after extensive conditioning in water. All photobase-catalyzed thiol-Michael polymerization matrices achieved >90% conversion with a dramatic reduction in shrinkage stress as compared with the unfilled dimethacrylate control. One prototype of ester-free thiol-Michael formulations had significantly better water uptake properties than the BisGMA/TEGDMA control system. Although exhibiting relatively lower Young's modulus and glass transition temperatures, highly uniform thiol-Michael materials achieved much higher toughness than the BisGMA/TEGDMA control. Moreover, low-ester thiol-Michael composite systems show stable mechanical performance even after extensive water treatment. Although further resin/curing methodology optimization is required, the photopolymerized thiol-Michael prototype resins can now be recognized as promising candidates for implementation in composite dental restorative materials.

Robotic surgery in trauma and orthopaedics: a systematic review

The use of robots in orthopaedic surgery is an emerging field that is gaining momentum. It has the potential for significant improvements in surgical planning, accuracy of component implantation and patient safety. Advocates of robot-assisted systems describe better patient outcomes through improved pre-operative planning and enhanced execution of surgery. However, costs, limited availability, a lack of evidence regarding the efficiency and safety of such systems and an absence of long-term high-impact studies have restricted the widespread implementation of these systems. We have reviewed the literature on the efficacy, safety and current understanding of the use of robotics in orthopaedics.

Meticillin-resistant Staphylococcus aureus screening in Wales: survey of practices in adult critical care units in Welsh hospitals

Screening for meticillin-resistant Staphylococcus aureus (MRSA) carriage in critical care units remains a controversial issue. This cross-sectional study reviewed the MRSA screening policies in adult critical care units in Welsh hospitals. Data were collected by structured questionnaires. The study showed a degree of variability in practice from universal screening to no screening at all. It is recommended that local MRSA policies should be reviewed, bearing in mind the local prevalence of colonization and infection; and compliance with basic infection control strategies should not only be directed at MRSA infection, but also at other healthcare-associated infections.

The value of ultrasound in assessing displacement of a medial clavicular physeal separation in an adolescent

We describe a case of medial clavicular physeal separation with posterior displacement of the metaphysis in a 13-year-old girl, focusing on the role played by ultrasound in the diagnosis, planning of treatment and post-reduction follow-up. On clinical examination and conventional radiography, the injury is essentially indistinguishable from a sternoclavicular dislocation or a fracture of the medial aspect of the clavicle; however, the pathogenesis is different, consisting in medial physeal separation and 'degloving' of the inner cancellous bone of the metaphysis from the surrounding periosteal collar with posterior metaphyseal dislocation. In our case, attempted closed reduction failed, and the injury required open reduction with relocation of the clavicle into the periosteal sleeve followed by suturing of the periosteal tear.

Classification of the morphology of the acromioclavicular joint using cadaveric and radiological analysis

The aim of this study was to establish a classification system for the acromioclavicular joint using cadaveric dissection and radiological analyses of both reformatted computed tomographic scans and conventional radiographs centred on the joint. This classification should be useful for planning arthroscopic procedures or introducing a needle and in prospective studies of biomechanical stresses across the joint which may be associated with the development of joint pathology.

We have demonstrated three main three-dimensional morphological groups namely flat, oblique and curved, on both cadaveric examination and radiological assessment. These groups were recognised in both the coronal and axial planes and were independent of age.

Outcome analysis of surgery for disorders of the rotator cuff: a comparison of subjective and objective scoring tools

A consecutive series of 372 patients who underwent surgery for disorders of the rotator cuff involving arthroscopic subacromial decompression and open or arthroscopic repairs of the cuff were prospectively investigated as to the comparability of subjective and objective assessment scores of shoulder function. Assessments were made before operation and at 3, 6, 12, 18 and 24 months after surgery using the Disabilities of the Arm, Shoulder, and Hand score, the Oxford shoulder score and the Constant-Murley score, which was used as a reference. All scores were standardised to a scale of 0 to 100 for comparison. Statistical analysis compared the post-operative course and the mean score for the subjective Disabilities to the Arm, Shoulder and Hand score and Oxford shoulder score, with the objective Constant score at each interval. A strong correlation was evident between both subjective scores and the Constant score. We concluded that both the subjective scores would be useful substitutes for the Constant score, obviating the need for a trained investigator and the specialist equipment required to perform the Constant score.

Lowering anti-dsDNA antibodies--what's new?

Antibodies to dsDNA are specific to SLE and are pathogenic, both due to their ability to deposit in tissues through a variety of mechanisms, and to their ability, when present in immune complexes, to activate inflammatory cells. The relationship of serum anti-dsDNA antibody levels to disease activity is a complex one and the factors that determine whether or not such antibodies will be pathogenic in an individual SLE patient are incompletely understood. Although anti-dsDNA antibodies can be made by naïve B cells and B cells belonging to the B1 and marginal zone subsets, pathogenic anti-dsDNA antibodies have the hallmarks of germinal center development and exposure to T cell help, including accumulation of somatic mutations and class switching to the IgG isotype. Epitope spreading may result in aquisition of cross-reactivities with multiple target organ antigens and aquisition of a memory phenotype will allow these B cells to acquire antigen presentation functions that amplify the autoreactive response. In the early stages of disease, or after remission induction protocols, autoreactive B cells may be susceptible to treatments that target T cell costimulation or that deplete or tolerize naïve and mature B cells. Therapeutic approaches targeting innate immune responses or regulatory T cells are starting to be tested in pre-clinical models. In later disease stages, memory and plasma cell accumulation may render patients more resistant to this type of therapeutic approach. Deposition of anti-dsDNA antibodies in target tissues can stimulate an inflammatory cascade that leads to tissue damage. A number of murine models have now been developed that show that interruption of this cascade can prevent or reverse such damage. This type of approach may be beneficial for individuals with established disease. As we learn more about the specific defects that cause SLE, it may become possible to individualize therapy based on patient specific biologic markers.

Quercetin: critical evaluation as an antileishmanial agent in vivo in hamsters using different vesicular delivery modes

Chemotherapy is still a major challenge for in vivo drug targeting to macrophages. Toxicity remains the major obstacle for the most potent drugs already known in the therapy of leishmaniasis. Thus, new drugs and new delivery systems are sought. By using different vesicular delivery modes e.g. liposomes, niosomes, microspheres and nanoparticles, attempts have been made to deliver an indigenous antileishmanial compound, quercetin, to treat experimental leishmaniasis in the hamster model so as to increase its efficacy as well as to reduce the toxicity. At equivalent quercetin concentration, the nanocapsulated quercetin was found to be the most potent in reducing the parasite burden in the spleen as well as in reducing hepatotoxcity and renaltoxicity compared to free drug or drug in other vesicular forms. An inverse relationship between the efficacy and the size of the vesicles was established. Such a drug vehicle formulation especially in the nanocapsulated form may be considered for clinical trials.

Bacopasaponin C: critical evaluation of anti-leishmanial properties in various delivery modes

Bacopasaponin C, an indigenous glycoside, was isolated from Indian medicinal plant Bacopa monniera (b. brahmi) and was tested for antileishmanial properties both in free and in various delivery modes, e.g., niosomes, microspheres, and nanoparticles that are used now as alternatives to more commonly used liposomes. The different vesicles were prepared by published protocols. The percent intercalation of Bacopasaponin C in liposomes, niosomes, and micropspheres determined at its absorption maximal (lambda(max) = 238 nm, epsilon = 8.6 x 10(3) M(-1) x cm(-1)) was found to be 30; for nanoparticles it was 50. At equivalent dose of 1.75 mg/kg body weight, every third day for a total of 6 doses in 15 days, Bacopasaponin C in all the vesicular forms was found to be very active. An inverse linear relationship between the efficacy and the size of the vesicles was established. As analyzed from tissue histology, blood pathology, and specific tests related to normal liver and kidney functions, Bacopasaponin C in each of the four vesicular forms was found to be without any side effects. Thus, because of its indigenous origin and non-toxic nature, Bacopasaponin C could very well be considered for application in the clinic through these alternative delivery modes.

A green Hunsdiecker reaction: synthesis of beta-bromostyrenes from the reaction of alpha,beta-unsaturated aromatic carboxylic acids with KBr and H2O2 catalysed by Na2MoO4.2H2O in aqueous medium

Reaction of alpha,beta-unsaturated aromatic carboxylic acids with KBr and H2O2 in the presence of Na2MoO4.2H2O in aqueous medium affords beta-bromo alkenes in high yield.

Changes in morphology of Paecilomyces japonica and their effect on broth rheology during production of exo-biopolymers

The influence of Paecilomyces japonica pellet morphology on fermentation broth rheology and exobiopolymer production was investigated in a 5-1 jar fermenter. Rapid formation of pellets was observed after the first day of fermentation; and these slowly increased in size and roughness. This, together with the increase in biomass concentration, altered the transport characteristics and broth rheology towards a pseudoplastic nature which, in turn, influenced cell growth and exo-biopolymer production. At mild agitation, high aeration and optimum substrate concentration, pellets were the most predominant morphological form, compared with free mycelia. The broth rheology showed pseudoplastic behavior; and the fungal morphology was closely related to the rheological properties.

Liposomal antioxidants in combating ischemia-reperfusion injury in rat brain

Liposome-encapsulated antioxidants have been tested in vivo to prevent oxidative attack during cerebral ischemia and reperfusion. Oxidative stress is a causal factor in the neuropathogenesis of ischemic-reperfusion injury. From the therapeutic point of view free chemical antioxidants were almost ineffective to protect cerebral tissues from those oxidative attacks. Thus an attempt has been made to prevent the oxidative damage due to the cerebral ischemic insult by the introduction of chemical antioxidants, ascorbic acid and alpha-tocopherol either encapsulated or intercalated in small unilamellar liposomes. The effectiveness of antioxidant-loaded liposomes was tested against an experimental in vivo rat model of global cerebral ischemia. Oxidative free radical attack on cerebral tissues by the ischemic insult and brief reperfusion was accounted for by the amount of diene production per unit of tissue protein. Diene production in ischemic reperfused rat brain increases almost twofold over that of the normal rats. Prevention of excess diene production has been attributed to rats when they were treated either with L-ascorbic acid-encapsulated liposomes or alpha-tocopherol intercalated liposomes 2 hours prior to the cerebral ischemic insult. Complete restriction of excess diene generation has also been achieved when a mixture of alpha-tocopherol and L-ascorbic acid-encapsulated liposomes were injected 3 hours before the ischemic infraction.

Production of inulooligosaccharides from chicory extract by endoinulinase from Xanthomonas oryzae No. 5

Inulooligosaccharides (IOS) production from chicory extract was carried out using endoinulinase obtained from a new isolate, Xanthomonas oryzae No. 5. The IOS production from chicory extract was maximum when 50 g/liter of chicory extract was utilized as the substrate. As the substrate concentration increased, the IOS production accordingly decreased probably due to substrate inhibition. For a comparative study, enzyme reactions were carried out from pure inulin as substrate. Though total IOS contents indicated higher IOS yield with pure inulin compared to that of chicory extract, the distribution of inulooligosaccharide components between pure inulin and chicory extract was not significantly different; i.e. DP5 and higher oligosaccharides are major products in case of both chicory extract and pure inulin as substrate. A considerable amount of oligofructose (about 30%, w/w), which were originally present in chicory extract, resulted in the change of the enzyme kinetics. A reaction pH 7 was found to be most suitable for enzyme reaction. The initial reaction rates increased with increasing enzyme dosage, although the relative composition of the IOS produced remain unchanged.

Extractive fermentation for improved production of endoglucanase by an intergeneric fusant of Trichoderma reesei/Saccharomyces cerevisiae using aqueous two-phase system

Extractive aqueous two-phase fermentation of endoglucanase, a key enzyme for the conversion of cellulosic substances to fermentable sugars, from an intergeneric fusant of Trichoderma reesei/Saccharomyces cerevisiae is a meaningful approach for better production and simple recovery of this enzyme. A phase composition of 6.5% (w/w) dextran and 7.5% (w/w) polyethylene glycol 6000, having a partition coefficient of 2.89 and 1.31 for endoglucanase from an intergeneric fusant of T. reesei/S. cerevisiae and T. reesei (WT) (being a control in this study), respectively, was chosen for extractive fermentation of the enzyme. Endoglucanase production is higher in medium containing polyethylene glycol (PEG) 6000 than in medium without PEG 6000. Comparative analysis of endoglucanase fermentation by fusant and T. reesei was carried out in shake culture and environment-controlled bioreactor conditions. The fusant produced 0.43U of endoglucanase (overall production: 0.34U) in the top phase of an aqueous two-phase system (ATPS), compared to 0.3U in medium without the phase system in shake culture. In a batch reactor, the endoglucanase level for the fusant in the top phase of ATPS was 0.49U (overall production: 0.40U), compared to 0.38U produced in medium without aqueous two-phase components. To corroborate this study, T. reesei produced 8.41U of endoglucanase (overall production: 5.96U) in the top phase of ATPS, compared to 7.18U in the medium without the phase system in shake culture. On the other hand, in a batch bioreactor, T. reesei produced 10.13U of endoglucanase (overall production: 6.90U) in the top phase of ATPS, compared to 8.56U of the enzyme in medium without aqueous two-phase components. The lower overall enzyme production by T. reesei in the two-phase system might be due to limitation in oxygen transfer to the dispersed phase where the enzyme is produced. A higher cell concentration and a reduced lag phase was obtained in ATPS, compared to a similar medium without phase forming polymers for both the intergeneric fusant of T. reesei/S. cerevisiae and T. reesei.

Targeting of liposomal andrographolide to L. donovani-infected macrophages in vivo

Despite the rapid development in medicinal and pharmaceutical technology, the targeting of drugs to phagocytic cells in macrophage-related diseases still remains a major unsolved problem. By using the mannosyl-fucosyl receptors on macrophages, attempts were made to target antileishmanial drugs encapsulated in mannosylated or fucosylated liposomes to treat experimental leishmaniasis in the hamster model. Mannosylated liposomes were found to be more potent in delivering antileishmanial drugs to phagocytic cells. Liposomes loaded with an indigenous drug, andrographolide, a labdane diterpenoid isolated from Indian medicinal plant Andrographis paniculata, were prepared and tested against experimental leishmaniasis in a hamster model. Mannosylated liposomes loaded with the drug were found to be most potent in reducing the parasitic burden in the spleen as well as in reducing the hepatic and renal toxicity. In addition, mannosylated drug-loaded liposome-treated animals showed a normal blood picture and splenic tissue histoarchitecture when compared with those treated with free drug or regular liposomal drug. Such a drug-vehicle formulation may be considered for clinical trials.

Aqueous two-phase: the system of choice for extractive fermentation

Extractive fermentation in aqueous two-phase systems is a meaningful approach to overcome low product yield in a conventional fermentation process, and by proper design of the two-phase system it is possible to obtain the product in a cell-free stream. The characteristics of an aqueous two-phase system, various polymers used for forming an aqueous two-phase system, the physicochemical parameters of the aqueous two-phase system, partitioning of biomolecules and cell mass and the effect of individual phase forming polymers on cell growth and product formation are reviewed in this article. The various extractive fermentation processes are also summarised here. At the end, the economic viability and scope of aqueous two-phase fermentation are briefly discussed in relation to the wider application of this topic.

Quantitative structure-activity relationship study on some nonpeptidal cholecystokinin antagonists

A quantitative structure-activity relationship (QSAR) analysis has been performed on a series of 1,4-benzodiazepine derivatives, which were found to act as antagonists of cholecystokinin (CCK), a gastrointestinal peptide hormone. The CCK acts with three different receptor subtypes termed as CCK-A, CCK-B, and gastrin receptor, which can be found in peripheral system, brain, and stomach, respectively. With all the three subtypes, the binding of the compounds is found to significantly depend on the lipophilicity of the compounds and their ability to form the hydrogen bonds with the receptor. However, the binding sites in CCK-A receptor seem to be slightly rigid as compared to those in CCK-B or gastrin receptor. The latter two appear to have similar binding features.

Villous adenomas and carcinoma of the duodenum in Gardner's syndrome

Patients with Gardner's syndrome are increasingly found to have polyps on routine upper gastrointestinal endoscopy, and their risk of developing periampullary carcinoma is between 3-12%. We report a 45 year old man with Gardner's syndrome who presented with periampullary carcinoma 5 years after colectomy. Review of the literature amassed another 21 cases of periampullary carcinoma in patients with Gardner's syndrome.