Integration of two models, or dominance of one?

Hobbis and Sutton attempted to integrate Cognitive Behavior Therapy (CBT) with the Theory of Planned Behavior (TPB). The possibility of such an integration portends exciting opportunities since behavioral interventions have had limited impact on behavior change. The integration, however, may more easily occur if Hobbis and Sutton had selected a formulation of the TPB that incorporated emotional variables, which is a primary focus of CBT. Furthermore, more work may be necessary to integrate the specific cognitive constructs between CBT and the TPB. Empirical research will be necessary to validate that the integration occurred in a meaningful way.     

Does patellar rim electrocautery have deleterious effects on patellar cartilage?

BackgroundCircumpatellar electrocauterization to destroy pain receptors during total knee arthroplasty without patellar resurfacing is commonly used to decrease postoperative knee pain. We aimed to evaluate the effect of denervation with electrocauterization on patellar cartilage.MethodsTwenty rabbits were randomly assigned to two equally sized case and control groups. The rabbits in the case group underwent surgery via the anterior midline skin incision and medial parapatellar arthrotomy, followed by denervation electrocauterization at a depth of 1 mm and a distance of 3 mm from the outer border of the patella. In the control group, surgery was identical to that performed in the case group, but without patellar denervation. Twelve weeks after surgery, all rabbits were sacrificed. Range of motion, macroscopic evaluation of cartilage using modified Outerbridge scoring, and histopathological assessment using a modified histologic scoring system for cartilage were evaluated.ResultsThree rabbits died during the study. Nine cases and eight animals from the control group were included in the final evaluation. All rabbits had passive full range of motion. Mean Outerbridge score was 2.0 in the case group and 0.37 in the control group (p = 0.002). There were statistically significant differences in cellularity (p = 0.016), loss of matrix (p = 0.004), and clustering of chondrocytes (p = 0.008) between the two groups. Microscopic variables as a whole were statistically significant (p = 0.001).ConclusionsCircumpatellar electrocauterization may result in cartilage destruction. So, we encourage caution in using routine electrocauterization in patients undergoing total knee arthroplasty.Level of evidencelevel II.     

A model of spike-timing dependent plasticity: one or two coincidence detectors?

In spike-timing dependent plasticity (STDP), synapses exhibit LTD or LTP depending on the order of activity in the presynaptic and postsynaptic cells. LTP occurs when a single presynaptic spike precedes a postsynaptic one (a positive interspike interval, or ISI), while the reverse order of activity (a negative ISI) produces LTD. A fundamental question is whether the "standard model" of plasticity in which moderate increases in Ca(2+) influx through the N-methyl-D-aspartate (NMDA) channels induce LTD and large increases induce LTP, can account for the order and interval sensitivity of STDP. To examine this issue we developed a model that captures postsynaptic Ca(2+) influx dynamics and the associativity of the NMDA receptors. While this model can generate both LTD and LTP, it predicts that LTD will be observed at both negative and positive ISIs. This is because longer and longer positive ISIs induce monotonically decreasing levels of Ca(2+), which eventually fall into the same range that produced LTD at negative ISIs. A second model that incorporated a second coincidence detector in addition to the NMDA receptor generated LTP at positive intervals and LTD only at negative ones. Our findings suggest that a single coincidence detector model based on the standard model of plasticity cannot account for order-specific STDP, and we predict that STDP requires two coincidence detectors.     

Does acupuncture or Chinese herbal medicine have a role in the treatment of allergic rhinitis?

PURPOSE OF REVIEW: Complementary medicines, including acupuncture and Chinese herbal medicine, are being used increasingly for the management of allergies such as allergic rhinitis. Until relatively recently, however, evidence for the efficacy and safety of these therapies in allergic conditions has been lacking. RECENT FINDINGS: A limited number of well conducted studies, all with small sample sizes, have demonstrated the promising therapeutic potential of acupuncture and Chinese herbal medicine for allergic rhinitis. The possible additional benefit of combining the two therapies, however, is yet to be confirmed. There are concerns about the appropriateness of the sham/placebo controls that have been used in acupuncture studies and also about the safety evaluation of individual herbs and herbal formulations. In addition to well established symptom scores and specific quality of life questionnaires, the concurrent use of conventional anti-allergy medications has been utilized as an outcome measure in a number of trials that have evaluated the effectiveness of acupuncture and Chinese herbal medicine for allergic rhinitis. SUMMARY: Tentatively, it appears that acupuncture and Chinese herbal medicine can be effective treatments for allergic rhinitis. Confirmatory evidence, however, is needed from large and, ideally, multi-centre trials.     

Does the shape of Plasmodium falciparum gametocytes have a function?

The gametocytes of Plasmodium falciparum have a characteristic banana-shape. One could wonder if this shape has been retained by selection forces because it favored transmission. By increasing the surface to volume ratio, the elongation that takes place during the maturation of P. falciparum gametocytes increases the susceptibility of gametocytes to rheological forces. This may facilitate their exit from the bone marrow and their subsequent impaction in the cutaneous capillaries that are lined with sequestered asexual parasites. The asymmetric curvature of gametocytes may tend to present gametocytes perpendicularly to the axis of the blood flow, thus increasing their chance to be retained and accumulate where they can be absorbed by the vector.     

Does the motor branch of the long head of the triceps brachii arise from the radial nerve?

Anatomy textbooks say that the motor branch of the long head of the triceps brachii (LHT) arises from the radial nerve. Some clinical observations of traumatic injuries of the axillary nerve with associated paralysis of the LHT have suggested that the motor branch of the LHT may arise from the axillary nerve. This anatomic study was performed, using both cadaver anatomical dissections and a surgical study, to determine the exact origin of the motor branch of the LHT. From the adult cadaver specimens (group I), 20 posterior cords were dissected from 10 subjects (eight embalmed, two fresh) using 3.5× magnification. The axillary nerve was followed from its onset to the posteromedial part of the surgical neck of the humerus and the radial nerve. We looked for the origin of the proximal branch of the LHT by a meticulous double anterior and posterior dissection. From the surgical group (group II), 15 posterior cords were dissected from 15 patients suffering from a C5-C6 injured paralysis, without paralysis of the LHT. During the surgical procedure, we looked for the origins of the motor branch of the LHT with a nerve stimulator. In group I, the motor branch of the LHT arose in 13 cases from the axillary nerve near its origin, in five cases from the terminal division of the posterior cord itself, and in two cases from the posterior cord 10 mm before its terminal division into the radial and axillary nerves. In no case did we find the motor branch of the LHT arising from the radial nerve. In eight cases, we found some accessory branches that arose near the principal branch. In group II, the motor branch of the LHT arose in 11 cases from the axillary nerve near its origin and in four cases from the terminal division of the posterior cord itself. The motor branch of the LHT never originated from the radial nerve. In four cases, we found some accessory branches that arose near the principal branch of the LHT. These results reveal that the motor branch of the LHT seems to originate most often from the axillary nerve. This contribution could be relevant for surgical treatment of traumatic nerve injuries.     

Suicides and serious suicide attempts: two populations or one?

BACKGROUND: Few studies have examined the extent to which populations of suicides and attempted suicides are similar, or different. This paper compares suicides and serious suicide attempts in terms of known risk factors for suicidal behaviour. METHODS: Using case-control methodology, risk factors for suicidal behaviour were examined in 202 individuals who died by suicide, 275 individuals who made medically serious suicide attempts and 984 randomly selected control subjects. Based on data from significant others, measures used spanned sociodemographic factors, childhood experiences, psychiatric morbidity and psychiatric history, exposure to recent stressful life events and social interaction. RESULTS: Multiple logistic regression identified the following risk factors that were common to suicide and serious suicide attempts: current mood disorder; previous suicide attempts; prior outpatient psychiatric treatment; admission to psychiatric hospital within the previous year; low income; a lack of formal educational qualifications; exposure to recent stressful interpersonal, legal and work-related life events. Suicides and suicide attempts were distinguished in the following ways: suicides were more likely to be male (OR = 1.9, 95% CI 1.1, 3.2); older (OR = 1.03, 95% CI 1.02, 1.04); and to have a current diagnosis of non-affective psychosis (OR = 8.5, 95% CI 2.0, 35.9). Suicide attempts were more likely than suicides to have a current diagnosis of anxiety disorder (OR = 3.5, 95% CI 1.6, 7.8) and to be socially isolated (OR = 2.0, 95% CI 1.2, 3.5). These findings were confirmed by discriminant function analysis, which identified two functions that described the three subject groups: the first function discriminated the two suicide groups from control subjects on a dimension corresponding to risk factors for suicide; the second function discriminated suicide from suicide attempt subjects on a series of factors including gender, non-affective psychosis and anxiety disorder. CONCLUSIONS: Suicides and medically serious suicide attempts are two overlapping populations that share common psychiatric diagnostic and history features, but are distinguished by gender and patterning of psychiatric disorder.     

Does low-intensity pulsed ultrasound stimulate maturation of tissue-engineered cartilage?

Traumatic events are a primary cause of local lesions of articular cartilage. Tissue engineered, cartilage-like structures represent an alternative to current treatment methods. The time necessary for tissue maturation and the mechanical quality of the regenerate at implantation are both critical factors for clinical success. Low-intensity pulsed ultrasound has proven to accelerate chondrogenesis in vitro. The goal of this study was to evaluate whether low-intensity pulsed ultrasound is capable of accelerating the process of cartilage maturation and increasing regenerate stability. Hyaline-like cartilage specimens were generated in vitro and subcutaneously implanted in the backs of nude mice. Twenty-eight animals received 20 min of low-intensity pulsed ultrasound treatment daily, and 28 animals received a sham treatment. Specimens were explanted after 1, 3, 6, and 12 weeks, mechanically tested with the use of an indentation test, histologically examined, and processed for RT-PCR. The Young's moduli significantly increased from 3 to 12 weeks, and at 6 weeks were comparable to those of native articular cartilage. In histological examination, specimens showed neocartilage formation. There was no significant difference between ultrasound-treated and sham-treated groups. The mechanical stability of the neocartilage specimens increased with treatment time and reached values of native cartilage after 6 weeks in vivo. Low-intensity pulsed-ultrasound stimulation showed no stimulatory effect on tissue maturation. In contrast, ultrasound-treated specimens showed a reduced Col 2 expression at 1 week and were significantly less stiff compared to native cartilage at 6 and 12 weeks. An acceleration of the maturation of tissue-engineered neocartilage in a clinical setting by means of low-intensity pulsed ultrasound therefore appears rather unrealistic.     

Post-natal molecular adaptations in anteromedial and posterolateral bundles of the ovine anterior cruciate ligament: one structure with two parts or two distinct ligaments?

The human anterior cruciate ligament (ACL) is a composite structure of two anatomically distinct bundles: an anteromedial (AM) and posterolateral (PL) bundles. Tendons are often used as autografts for surgical reconstruction of ACL following severe injury. However, despite successful surgical reconstruction, some people experience re-rupture and later development of osteoarthritis. Understanding the structure and molecular makeup of normal ACL is essential for its optimal replacement. Reportedly the two bundles display different tensions throughout joint motion and may be fundamentally different. This study assessed the similarities and differences in ultrastructure and molecular composition of the AM and PL bundles to test the hypothesis that the two bundles of the ACL develop unique characteristics with maturation. ACLs from nine mature and six immature sheep were compared. The bundles were examined for mRNA and protein levels of collagen types I, III, V, and VI, and two proteoglycans. The fibril diameter composition of the two bundles was examined with transmission electron microscopy. Maturation does alter the molecular and structural composition of the two bundles of ACL. Although the PL band appears to mature slower than the AM band, no significant differences were detected between the bundles in the mature animals. We thus reject our hypothesis that the two ACL bundles are distinct. The two anatomically distinct bundles of the sheep ACL can be considered as two parts of one structure at maturity and material that would result in a structure of similar functionality can be used to replace each ACL bundle in the sheep.     

Matrix model of clinical psychology: applause or the sound of one hand clapping?

The matrix model as proposed by C.R. Snyder and T.R. Elliott (this issue, pp.1033-1054) is a welcome refocusing of clinical psychology for the 21st century. Yet, limitations to the model are that (a) it shifts attention to the target of interventions (i.e., "clients") and virtually ignores the function of the interventionist; (b) it might not be the best way to characterize "clients"; and (c) training might take longer than 5 years. Overall, it is a heuristic model; will it be accepted?     

Does radiation-induced fibrosis have an important role in pathophysiology of the osteoradionecrosis of jaw?

Osteoradionecrosis of the mandible is a serious complication following radiation therapy with or without surgical intervention for malignancies of the head and neck. The acknowledged clinical presentation of osteoradionecrosis is pain, fistulae of mucosa or skin, complete devitalization of bone and pathological fractures. Radiation-induced fibrosis is an irreversible pathological process, which leads to damages in lung, skin, intestine, and pelvic cavity after radiotherapy. Studies have proved that radiation-induced fibrosis is involved in the pathological onset, development, maintenance of osteoradionecrosis and there is dose-effect relationship between them, so the authors hypothesize that radiation-induced fibrosis plays an important role in osteoradionecrosis. Studies need to perform to look for more efficient methods of managing and preventing the osteoradionecrosis.     

Intramedullary femoral nails: one or two lag screws? A preliminary study

Failures of proximal femoral nails that treat unstable femoral fractures have been reported. In this communication, a finite element model to include a proximal femoral nail within a fractured femur was used to carry out preliminary investigations into configurations of single or double lag screws. The effects of the different types of fracture were investigated. The results show that in order to share the load evenly between two lag screws, a good configuration seems to be to have a slightly larger screw above the lower screw. This also ameliorates stresses in the nail at the lag screw insertion holes. However, using two screws in this way can lead to large stresses in the cancellous bone in the femoral head, and these stresses may be significant in the initiation of cut-out.     

Does antimicrobial use increase the rate of antimicrobial resistance? A one year experience

Antimicrobial resistance has been a challenge in all countries. The aim of this study is to ascertain the risk factors that predispose patients to infections with extended spectrum beta lactamase (ESBL)-producing gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA). Patients who were treated in the secondary care hospital due to infections in 2009 and their isolates were evaluated retrospectively. In total, 174 patients and their 189 isolates, which contained 36 ESBL-producing gram-negative bacteria, 112 non-ESBL-producing gram-negative bacteria, and 41 gram-positive bacteria were evaluated retrospectively. Hospitalisation in the previous 3 months, comorbidity, and usage of amoxicillin-clavulanate in the previous 3 months were determined to be the risk factors associated with infections by the ESBL-producing gram-negative bacteria. Hospitalisation was found to be a risk factor for infection with MRSA. Hospitalisation and underlying conditions increase the colonisation with resistant bacteria and resistance rates in the patients, hospitals and communities. An infection control programme should be contemplated not only for hospitals, but also for the greater community.     

The couple's decision-making in IVF: one or two embryos at transfer?

BACKGROUND: The aim of this study was to evaluate the decision-making process and factors that contribute to the decision of IVF participants to choose one or two embryos at transfer. METHODS: Two hundred and seventy-four IVF patients equally distributed in males and females were personally interviewed using a semi-structured questionnaire which included 82 items. RESULTS: In the whole study population, previous childbirth [odds ratio (OR) 2.1; 95% confidence interval (CI) 1.9-3.6], and spare embryos to freeze (OR 23.6; 95% CI 11.2-54.5) emerged as the most important variables in patients who had one embryo transferred, while previous IVF treatments (OR 0.3; 95% CI 0.1-0.6) and the assumed increased pregnancy chance (OR 0.1; 95% CI 0.05-0.3) were the most important decision-making factors among those who had two embryos. The women were more satisfied with the information (83 versus 71%; P = 0.02), and more aware of the risks with twin pregnancies (77 versus 66%; P = 0.03) than the males. The women were also more concerned about their age. Knowledge about risks of multiple pregnancies was higher in females (77%) than in males (66%, P = 0.03). CONCLUSION: The results of this study indicate that despite good information about the risks for complications with multiple pregnancies, many patients wish to have two embryos transferred. Spare embryos to freeze, improvement of pregnancy rate in single embryo transfer and young age of the woman are predictive of choosing single embryo transfer. However, the final decision must always be made in agreement with the physician.     

Reference assays for Clostridium difficile infection: one or two gold standards?

Accurate diagnosis of Clostridium difficile infection (CDI) is essential for optimal treatment, prevention and control. There are two reference assays for CDI diagnosis: the cell cytotoxicity assay (CCTA) and toxigenic culture (TC). Importantly, these tests actually detect different targets: CCTA detects the presence of C difficile toxins (primarily toxin B, but also toxin A), whereas TC detects the presence in the stool of C difficile with the potential to produce toxin. Not surprisingly studies comparing the results of these assays show imperfect agreement. Thus, a faecal sample may be CCTA negative but TC positive, and this raises the crucial question about the clinical significance of the presence of C difficile with the capacity to produce toxin but no actual detectable free toxin. A positive TC result indicates that a patient with diarrhoea is potentially infectious. TC also has the advantage that the cultured isolate is available for typing and for susceptibility testing. In general, however, CCTA has been shown to be a better test for the laboratory confirmation of CDI, although additional culture may be needed to optimise sensitivity. Crucially, when these reference assays are used to determine the accuracy of alternative diagnostic tests, care should be taken to compare methods with their appropriate standard (ie, compare tests that target equivalent end-points). Such issues have contributed to the variable and often suboptimal performance of rapid diagnostic tests for CDI. Further research is urgently needed to improve knowledge of the utility of routine diagnostic tests in CDI and the factors that influence their performance.