Ethics of the use of dead human bodies in anatomy teaching in India

The study of the human anatomy predominantly requires the use of remains of the dead. Unclaimed bodies are easily available in India; however, there is a lack of clear ethical guidelines governing their transport and exchange. We raise pertinent questions about the ethical implications of using unclaimed bodies in teaching anatomy, their transport, transfer and storage, ethical and legal issues regarding the voluntary donation of bodies and dry human bones, as well as the commercial aspects of body donation. We also examine existing practices in anatomy departments in India, and explore the available legal safeguards. We detail practical and ethical challenges in the existing practices and safeguards and attempt to provide solutions.

Ethics of the use of dead human bodies in anatomy teaching in India

The study of the human anatomy predominantly requires the use of remains of the dead. Unclaimed bodies are easily available in India; however, there is a lack of clear ethical guidelines governing their transport and exchange. We raise pertinent questions about the ethical implications of using unclaimed bodies in teaching anatomy, their transport, transfer and storage, ethical and legal issues regarding the voluntary donation of bodies and dry human bones, as well as the commercial aspects of body donation. We also examine existing practices in anatomy departments in India, and explore the available legal safeguards. We detail practical and ethical challenges in the existing practices and safeguards and attempt to provide solutions.

Serotonergic regulation of bipolar cell survival in the developing cerebral cortex

One key factor underlying the functional balance of cortical networks is the ratio of excitatory and inhibitory neurons. The mechanisms controlling the ultimate number of interneurons are beginning to be elucidated, but to what extent similar principles govern the survival of the large diversity of cortical inhibitory cells remains to be investigated. Here, we investigate the mechanisms regulating developmental cell death in neurogliaform cells, bipolar cells, and basket cells, the three main populations of interneurons originating from the caudal ganglionic eminence and the preoptic region. We found that all three subclasses of interneurons undergo activity-dependent programmed cell death. However, while neurogliaform cells and basket cells require glutamatergic transmission to survive, the final number of bipolar cells is instead modulated by serotonergic signaling. Together, our results demonstrate that input-specific modulation of neuronal activity controls the survival of cortical interneurons during the critical period of programmed cell death.

Spindle reorientation in response to mechanical stress is an emergent property of the spindle positioning mechanisms

Proper orientation of the mitotic spindle plays a crucial role in embryos, during tissue development, and in adults, where it functions to dissipate mechanical stress to maintain tissue integrity and homeostasis. While mitotic spindles have been shown to reorient in response to external mechanical stresses, the subcellular cues that mediate spindle reorientation remain unclear. Here, we used a combination of optogenetics and computational modeling to investigate how mitotic spindles respond to inhomogeneous tension within the actomyosin cortex. Strikingly, we found that the optogenetic activation of RhoA only influences spindle orientation when it is induced at both poles of the cell. Under these conditions, the sudden local increase in cortical tension induced by RhoA activation reduces pulling forces exerted by cortical regulators on astral microtubules. This leads to a perturbation of the balance of torques exerted on the spindle, which causes it to rotate. Thus, spindle rotation in response to mechanical stress is an emergent phenomenon arising from the interaction between the spindle positioning machinery and the cell cortex.

Radiographic extent of maxillofacial Gorham's disease and its impact on recurrence: A systematic review

OBJECTIVE

This systematic review assessed the radiographic extent of maxillofacial Gorham's disease and its impact on recurrence.

STUDY DESIGN

PubMed and Cochrane databases were searched. The key words were (Gorham Disease OR Vanishing Bone Disease OR Gorham Stout Syndrome) AND (Jaw OR Maxilla OR Mandible OR Maxillofacial).

RESULTS

Forty-one cases from 39 articles were included. Based on radiographic extent, the lesions were classified as large or small. Most cases occurred in the mandible (24), followed by a combination of maxilla and/or mandible and other bones (12), both mandible and maxilla (3), and maxilla only (2). Only mandibular cases were analyzed for radiographic extent. Of the 24 mandibular lesions, 16 were large and 8 were small. Nine of the large lesions occurred in the young age group with 2 recurrences, followed by 5 in the middle-aged group with 1 recurrence. Small lesions were nearly equally distributed over the age groups, with 2 recurrences in the middle-aged group and 1 recurrence in the adult age group. Age, sex, and lesion size had no significant effect on recurrence.

CONCLUSIONS

Radiographic extent of the lesion does not impact recurrence, suggesting a possible existence of aggressive and nonaggressive variants of maxillofacial Gorham's disease.

Intrinsic Efficacy of Opioid Ligands and Its Importance for Apparent Bias, Operational Analysis, and Therapeutic Window

Evidence from several novel opioid agonists and knockout animals suggests that improved opioid therapeutic window, notably for analgesia versus respiratory depression, is a result of ligand bias downstream of activation of the µ-opioid receptor (MOR) toward G protein signaling and away from other pathways, such as arrestin recruitment. Here, we argue that published claims of opioid bias based on application of the operational model of agonism are frequently confounded by failure to consider the assumptions of the model. These include failure to account for intrinsic efficacy and ceiling effects in different pathways, distortions introduced by analysis of amplified (G protein) versus linear (arrestin) signaling mechanisms, and nonequilibrium effects in a dynamic signaling cascade. We show on both theoretical and experimental grounds that reduced intrinsic efficacy that is unbiased across different downstream pathways, when analyzed without due considerations, does produce apparent but erroneous MOR ligand bias toward G protein signaling, and the weaker the G protein partial agonism is the greater the apparent bias. Experimentally, such apparently G protein-biased opioids have been shown to exhibit low intrinsic efficacy for G protein signaling when ceiling effects are properly accounted for. Nevertheless, such agonists do display an improved therapeutic window for analgesia versus respiratory depression. Reduced intrinsic efficacy for G proteins rather than any supposed G protein bias provides a more plausible, sufficient explanation for the improved safety. Moreover, genetic models of G protein-biased opioid receptors and replication of previous knockout experiments suggest that reduced or abolished arrestin recruitment does not improve therapeutic window for MOR-induced analgesia versus respiratory depression. SIGNIFICANCE STATEMENT: Efforts to improve safety of µ-opioid analgesics have focused on agonists that show signaling bias for the G protein pathway versus other signaling pathways. This review provides theoretical and experimental evidence showing that failure to consider the assumptions of the operational model can lead to large distortions and overestimation of actual bias. We show that low intrinsic efficacy is a major determinant of these distortions, and pursuit of appropriately reduced intrinsic efficacy should guide development of safer opioids.

Challenges and ethical issues in the course of palliative care management for people living with advanced neurologic diseases

In the recent years, there has been an increase in awareness with regards to the role of palliative care (PC) in management of neurologic diseases. In 1996, the need to incorporate PC in the care for patients with neurologic conditions was recognized by the American Academy of Neurology (AAN) Ethics and Humanities Subcommittee. The gaps in research, education and the ability to deliver adequate PC were then acknowledged by the National Academy of Sciences with their publication of "Approaching death: improving care at the end of life" and most recently, continued goals in improving PC was highlighted by another recent publication "Dying in America: improving quality and honoring individual preferences near the end of life". The complexity of managing neurologic patients brings about challenges and ethical issues in this setting. The aim of this review is to discuss and summarize the challenges and ethical issues in the context of PC management of patients with advanced acute, rapidly progressive, slowly-progressive or degenerative neurological conditions that are commonly encountered in practice.

Inhibition Patterns the Whisking Rhythm

In this issue of Neuron, Deschênes et al. (2016) propose that rhythmic inhibition of whisker motor neurons is a key pattern generator underlying exploratory whisking. The inhibitory premotor neurons located in the brainstem reticular formation are synchronized by breathing-related oscillators.

Parallel pathways from whisker and visual sensory cortices to distinct frontal regions of mouse neocortex

The spatial organization of mouse frontal cortex is poorly understood. Here, we used voltage-sensitive dye to image electrical activity in the dorsal cortex of awake head-restrained mice. Whisker-deflection evoked the earliest sensory response in a localized region of primary somatosensory cortex and visual stimulation evoked the earliest responses in a localized region of primary visual cortex. Over the next milliseconds, the initial sensory response spread within the respective primary sensory cortex and into the surrounding higher order sensory cortices. In addition, secondary hotspots in the frontal cortex were evoked by whisker and visual stimulation, with the frontal hotspot for whisker deflection being more anterior and lateral compared to the frontal hotspot evoked by visual stimulation. Investigating axonal projections, we found that the somatosensory whisker cortex and the visual cortex directly innervated frontal cortex, with visual cortex axons innervating a region medial and posterior to the innervation from somatosensory cortex, consistent with the location of sensory responses in frontal cortex. In turn, the axonal outputs of these two frontal cortical areas innervate distinct regions of striatum, superior colliculus, and brainstem. Sensory input, therefore, appears to map onto modality-specific regions of frontal cortex, perhaps participating in distinct sensorimotor transformations, and directing distinct motor outputs.

Dental complications of herpes zoster: Two case reports and review of literature

Herpes zoster (HZ) (shingles) results due to reactivation of varicella-zoster virus. Unusual dental complications like osteonecrosis, exfoliation of teeth, periodontitis, and calcified and devitalized pulps, periapical lesions, and resorption of roots as well as developmental anomalies such as irregular short roots and missing teeth may arise secondary to involvement of 2nd or 3rd division of trigeminal nerve by HZ. Such cases pose both a diagnostic as well as a therapeutic challenge. We report two such rare dental complications of HZ-spontaneous tooth exfoliation and osteonecrosis of the maxilla in a 70-year-old female patient; and multiple periapical pathoses affecting right half of the mandibular teeth in a 45-year-old female patient. Both the patients did not have any associated systemic illness. The aim of this paper was to compare the present cases with all the 46 cases of osteonecrosis and 6 cases of multiple periapical pathoses secondary to trigeminal zoster reported in literature till date The article also throws light that the occurrence of such dental complications of HZ is not entirely dependent on the immune status of the host.

Parallel pathways from motor and somatosensory cortex for controlling whisker movements in mice

Mice can gather tactile sensory information by actively moving their whiskers to palpate objects in their immediate surroundings. Whisker sensory perception therefore requires integration of sensory and motor information, which occurs prominently in the neocortex. The signalling pathways from the neocortex for controlling whisker movements are currently poorly understood in mice. Here, we delineate two pathways, one originating from primary whisker somatosensory cortex (wS1) and the other from whisker motor cortex (wM1), that control qualitatively distinct movements of contralateral whiskers. Optogenetic stimulation of wS1 drove retraction of contralateral whiskers while stimulation of wM1 drove rhythmic whisker protraction. To map brainstem pathways connecting these cortical areas to whisker motor neurons, we used a combination of anterograde tracing using adenoassociated virus injected into neocortex and retrograde tracing using monosynaptic rabies virus injected into whisker muscles. Our data are consistent with wS1 driving whisker retraction by exciting glutamatergic premotor neurons in the rostral spinal trigeminal interpolaris nucleus, which in turn activate the motor neurons innervating the extrinsic retractor muscle nasolabialis. The rhythmic whisker protraction evoked by wM1 stimulation might be driven by excitation of excitatory and inhibitory premotor neurons in the brainstem reticular formation innervating both intrinsic and extrinsic muscles. Our data therefore begin to unravel the neuronal circuits linking the neocortex to whisker motor neurons.

A rapid and low-cost microscopic observation drug susceptibility assay for detecting TB and MDR-TB among individuals infected by HIV in South India

BACKGROUND

The converging epidemics of HIV and tuberculosis (TB) pose one of the greatest public health challenges of our time. Rapid diagnosis of TB is essential in view of its infectious nature, high burden of cases, and emergence of drug resistance.

OBJECTIVE

The purpose of this present study was to evaluate the feasibility of implementing the microscopic observation drug susceptibility (MODS) assay, a novel assay for the diagnosis of TB and multi-drug-resistant tuberculosis (MDR-TB) directly from sputum specimens, in the Indian setting.

MATERIALS AND METHODS

This study involved a cross-sectional, blinded assessment of the MODS assay on 1036 suspected cases of pulmonary TB in HIV-positive and HIV-negative patients against the radiometric method, BD-BACTEC TB 460 system.

RESULTS

Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of the MODS assay in detecting MTB among TB suspected patients were 89.1%, 99.1%, 94.2%, 95.8%, respectively. In addition, in the diagnosis of drug-resistant TB, the MODS assay was 84.2% sensitive for those specimens reporting MDR, 87% sensitivity for those specimens reporting INH mono-resistance, and 100% sensitive for specimens reporting RIF mono-resistance. The median time to detection of TB in the MODS assay versus BACTEC was 9 versus 21 days (P<0.001).

CONCLUSION

Costing 5 to 10 times lesser than the automated culture methods, the MODS assay has the potential clinical utility as a simple and rapid method. It could be effectively used as an alternative method for diagnosing TB and detection of MDR-TB in a timely and affordable way in resource-limited settings.

Cowden syndrome- Clinico-radiological illustration of a rare case

Cowden syndrome (CS) or multiple hamartoma syndrome is an infrequent genodermatoses, which is inherited as an autosomal dominant trait resulting from the mutation in the Phosphatase and Tensin homolog gene on the arm 10q and is principally characterized by multiple hamartomas with an increased risk of development of malignancies. Facial and oral signs are remarkable in the form of multiple papules and trichilemmomas on the face. We report one such rare case of CS in a 19-year-old patient who was diagnosed on the basis of her oral mucosal lesions and was further investigated and diagnosed with other hamartomas. The present case report signifies the responsibility of the oral physician in the early diagnosis of this progressive pathological syndrome as it leaves its footmark in the oral cavity in the form of oral mucosal lesions.

Dystonia in a Patient with Melanoma Metastatic to the Brain Treated with High-Dose Interleukin-2, Radiation Therapy, and Levetiracetam

Dystonia has been described as a potential toxicity of radiation therapy. Management of this rare movement disorder is targeted in symptom improvement. We report a case of a 46-year-old female patient who developed dystonia during treatment of melanoma metastatic to the brain and discuss potential causes of and therapies for this rare complication.

Prediction by promoter logic in bacterial quorum sensing

Quorum-sensing systems mediate chemical communication between bacterial cells, coordinating cell-density-dependent processes like biofilm formation and virulence-factor expression. In the proteobacterial LuxI/LuxR quorum sensing paradigm, a signaling molecule generated by an enzyme (LuxI) diffuses between cells and allosterically stimulates a transcriptional regulator (LuxR) to activate its cognate promoter (pR). By expressing either LuxI or LuxR in positive feedback from pR, these versatile systems can generate smooth (monostable) or abrupt (bistable) density-dependent responses to suit the ecological context. Here we combine theory and experiment to demonstrate that the promoter logic of pR – its measured activity as a function of LuxI and LuxR levels – contains all the biochemical information required to quantitatively predict the responses of such feedback loops. The interplay of promoter logic with feedback topology underlies the versatility of the LuxI/LuxR paradigm: LuxR and LuxI positive-feedback systems show dramatically different responses, while a dual positive/negative-feedback system displays synchronized oscillations. These results highlight the dual utility of promoter logic: to probe microscopic parameters and predict macroscopic phenotype.

Bacterial cells constantly communicate with one another by exchanging chemical signals, which constitute a rich source of information about the proximity of friends or foes in the environment. These signals can be used to coordinate the actions of cells across a population. For example, pathogenic bacteria infecting a host can remain quiescent, only becoming virulent once they attain a sufficient cell density. Such coordination, regulated by so-called quorum-sensing systems, works on the following principle: every cell in the population secretes a specific chemical signal; the more cells there are, the more signal is generated; when individual cells sense that the signal has crossed some threshold, they launch a response. The nature of the response depends on the detailed molecular wiring of the secretion and sensing system, which can vary from species to species. It is often impossible to determine all these molecular details for any given system. Borrowing ideas from control theory, we show that this internal wiring can be largely ignored, and these systems can be considered as ‘black boxes’. Our experiments demonstrate that the measured input-output logic of the black box, which we term ‘promoter logic’, is sufficient to predict the diverse responses of different quorum-sensing systems.

Motor control by sensory cortex

Classical studies of mammalian movement control define a prominent role for the primary motor cortex. Investigating the mouse whisker system, we found an additional and equally direct pathway for cortical motor control driven by the primary somatosensory cortex. Whereas activity in primary motor cortex directly evokes exploratory whisker protraction, primary somatosensory cortex directly drives whisker retraction, providing a rapid negative feedback signal for sensorimotor integration. Motor control by sensory cortex suggests the need to reevaluate the functional organization of cortical maps.

Frosted cylindrical lens induced artefact on Humphrey automated perimetry

BACKGROUND

The aim of this study was to assess the effect of a cylindrical corrective lens with frosted sides on Humphrey automated perimetry performed with a translucent spectacle occluder in the contralateral eye.

METHODS

Ten healthy volunteers with cylindrical refractive errors of more than 1.50 DC had Humphrey visual fields (30-2) measured with the contralateral eye occluded with either a translucent spectacle occluder or an opaque patch. The order of testing with each occluder was randomised. Additionally, visual field examination with the opaque patch was performed on three volunteer subjects with deep-set eyes to establish the clinical significance of the frosted cylindrical lens induced artefact (CLA). The back vertex distances for the correcting lenses were measured for all tests.

RESULTS

Eight out of 10 volunteers tested with the translucent occluder demonstrated CLA, which was absent when the opaque patch was used. The presence of an artefact corresponding to the axis of the cylinder was observed, when the vertex distance was more than 15 mm. Three subjects with deep-set eyes presented with CLA, even with the use of an opaque patch.

DISCUSSION

Cylindrical lens artefacts can occur with increasing vertex distance when using a translucent spectacle occluder instead of an opaque patch. CLA is also seen in subjects with deep-set eyes.

Flavivirus West Nile (Sarafend) egress at the plasma membrane

West Nile (Sarafend) virus was distinctly observed to bud from the plasma membrane rather than mature intracellularly. This has been observed with transmission electron microscopy. Using conventional scanning electron microscopy, budding at the plasma membrane especially at the filopodia was clearly illustrated. Immunogold labelling against the virus envelope protein was also performed to confirm this mode of exit. The gold particles were observed to be located at the sites where virus budding was seen under the field emission scanning electron microscope.

Brefeldin A affects West Nile virus replication in Vero cells but not C6/36 cells

A fungal metabolite brefeldin A (BFA) was used to study virus-host interaction in glycoprotein processing in West Nile virus-infected Vero and C6/36 cells. The results indicated that as little as 1 microgram/ml of BFA resulted in complete breakdown in the Golgi organelle in infected Vero cells. This led to modifications of the glycoproteins which could not be efficiently used in infectious virion formation. In contrast, as much as 10 micrograms/ml of BFA in culture medium did not affect either glycoprotein formation or production of infectious particles in C6/36 cells. The results showed that in Vero cells, the transport of glycoproteins to the Golgi apparatus is important in West Nile virus infection. It also showed that BFA could be used as a tool to understand further the trafficking of glycoprotein from the ER to Golgi in flavivirus infection in Vero cells.

Role of endogenous prostaglandins in volume expansion and during furosemide infusion in conscious dogs

The renal effects of two structurally dissimilar inhibitors of prostaglandin synthesis (Meclofenamate and RO-20-5720) were studied in conscious, chronically instrumented dogs during mild volume expansion and during a constant infusion of furosemide. When either inhibitor was administered following volume expansion, urinary excretion of PGE2 and urine flow rate were reduced by more than 50%. In contrast, renal plasma flow fell by less than 10% while glomerular filtration rate, sodium excretion, and plasma renin activity (PRA) were unchanged. In separate studies, infusion of furosemide increased renal plasma flow, urine flow rate, sodium excretion, PRA, and urinary excretion of PGE2, while glomerular filtration rate decreased. Administration of inhibitors of prostaglandin synthesis during constant infusion of furosemide reduced the urinary excretion of PGE2 to control levels, as renal plasma flow and glomerular filtration rate fell below control level. Despite these hemodynamic alterations, the furosemide-induced diuresis and increase in PRA were only partly attenuated by prostaglandin inhibition. It is concluded that in conscious dogs, intrarenal prostaglandins modulate urine flow rate during mild volume expansion and play a major role in mediating the renal hemodynamic effects of furosemide.