Anosognosia in parietal lobe syndrome

Patients with right parietal lesions often deny their paralysis (anosognosia), but do they have "tacit" knowledge of their paralysis? I devised three novel tests to explore this. First, the patients were given a choice between a bimanual task (e.g., tying shoe laces) vs a unimanual one (e.g., threading a bolt). They chose the former on 17 of 18 trials and, surprisingly, showed no frustration or learning despite repeated failed attempts. I conclude that they have no tacit knowledge of paralysis (or, if such knowledge exists, it is not available for this particular task). Second, I used a "virtual reality box" to convey the optical illusion to the patient that she was moving her paralyzed left hand up and down to the rhythm of a metronome, and yet she showed no sign of surprise. Third, I irrigated patient BM's left ear canal with cold water, a procedure that is known to shift that patient's spatial frame of reference by stimulating the vestibular system. Surprisingly, this allowed her "repressed" memory of the paralysis to come to the surface; she said she had been paralyzed continuously for several days. I suggest that the vestibular stimulation produces these remarkable effects by mimicking REM sleep. These patients also employ a whole arsenal of grossly exaggerated Freudian "defense mechanisms" to account for their paralysis. To explain this, I propose that in normal individuals the left hemisphere ordinarily deals with small, local anomalies by trying to impose consistency but, when the anomaly exceeds threshold, an interaction with the right hemisphere forces a "paradigm shift." A failure of this process, in patients with right hemisphere damage, might partially account for anosognosia. Finally, I present a new conceptual framework that may help link several psychological and neurological phenomena such as Freudian defense mechanisms, vestibular stimulation, anosognosia, memory repression, visual illusions, anterograde amnesia, REM sleep, dreaming, and humor.     

Taming the killer in the kitchen: mitigating household air pollution from solid-fuel cookstoves through building design

In this study, we attempt to mitigate household air pollution (HAP) through improved kitchen design. Field surveys were conducted in ten kitchens of rural western India, which were then modelled and simulated for dynamic indoor airflow network analysis. The simulated results were statistically clustered using principal component analysis and hierarchical agglomerative clustering, to construct a cumulative built environment parameter called ‘Built Factor’ for each kitchen, and subsequently a derivative matrix was developed. Categorization of better performing kitchens from this derivative matrix enabled in deriving the built parameter thresholds for a ‘better’ kitchen design. This derived kitchen showed 60 % reduction in PM2.5 peak concentration during cooking hours. The evaluation described here is essentially a “proof of concept”, that effective building design can be an alternative way to reduce HAP without the introduction of chimneys, improved cookstoves or shifting to cleaner fuel.     

Life cycle energy and carbon footprint analysis of photovoltaic battery microgrid system in India

Electricity supply in India is from a centralized grid. Many parts of the country experience grid interruptions. Life cycle energy and environmental analysis has been done for a 27 kWp photovoltaic system which acts as grid backup for 3 h outage in an Indian urban residential scenario. This paper discusses energy requirements and carbon emission for a PV storage system for five different battery technologies in Indian context. This can be used as a metric for comparative analysis for new batteries, with an undeveloped market. The energy requirements for the components are quantified and are compared in terms of energy payback time (EPBT) and Net Energy Ratio (NER). All the calculations are done for Indian context. EPBT is found to be in the range of 2–4.5 years for all the systems, while NER is in the range of 6.6–2.52. NaS has the highest emission factor of 0.67 kgCO₂/kWh and the least for NiCd (0.091 kgCO₂/kWh). These factors can be used to select a PV battery option and to target selection of materials and systems based on the reported values.     

Adrenal chromaffin cells on microcarriers exhibit enhanced long-term functional effects when implanted into the mammalian brain

Rat adrenal chromaffin cells attached to either collagen-coated dextran (Cytodex 3) or glass bead microcarriers, both of 90-200 microns diameter, were used as dopamine-secreting implants in the caudate-putamen of rats with 6-hydroxydopamine-induced unilateral lesions of the substantia nigra. As controls, beads without cells and cells in suspension alone were implanted. Chromaffin cells adhered to microcarriers reduced apomorphine-induced rotation by 75% in lesioned animals. Animals that were lesioned but not receiving cell implants or receiving beads alone showed no reduction. Animals implanted with cells not attached to beads also showed a reduction in rotation but this effect lasted less than three months. Microcarrier-attached cells, however, maintained their effect in reducing rotation for at least eight months (rotations were reduced from a control mean of 10.9 +/- 1.4 to 3.6 +/- 1.1 turns/min) without any "drop-off" of the effect. Histological examination showed that eight months post-implant the cells pre-adhered to beads were still present and could be stained by anti-tyrosine hydroxylase antibody. Sections stained with hematoxylin-eosin showed no signs of an inflammatory response. In contrast to beads implanted into the striatum, Cytodex bead implants injected into the lateral ventricle induced a histopathological response appearing to involve the ependyma and choroid plexus. Results suggest that the striatal parenchyma but not the ventricle is amenable to studies using the microcarrier approach to transplantation.     

Voltage sensitivity of the osteoclast calcium receptor

We demonstrated previously that osteoclasts possess a divalent cation-sensitive "receptor", the Ca2+ receptor. Activation of the Ca2+ receptor by the surrogate cation Ni2+ was shown to elicit an increase in cytosolic [Ca2+] to a peak value followed by an exponential decline. In the present study we examined the influence of surface membrane voltage on the kinetics of Ca2+ receptor inactivation. The K+ ionophore, valinomycin was applied to intercept the declining phase of the cytosolic [Ca2+] transient elicited by application of between 50 microM- and 5 mM-[Ni2+]. This resulted in a sustained elevation of cytosolic [Ca2+] or even a 'hump' followed by a gradual decline. Such a kinetic alteration persisted in a Ca(2+)-free solution, but was abolished in high extracellular [K+] (105 mM). Thus, we demonstrate for the first time to our knowledge, a modulatory effect of membrane potential on the function of the osteoclast Ca2+ receptor.     

Interaction of calcium channel antagonists with calcium: spectroscopic and modeling studies on diltiazem and its Ca2+ complex

Using spectral techniques, the solution conformation of diltiazem was studied in acetonitrile with special reference to the effect of Ca2+ on the drug structure. Complete assignment of the proton resonances in the 1H-NMR spectrum of the drug was made using one-and two-dimensional spectral analyses. A two-dimensional 1H-NOESY spectrum (in the phase-sensitive mode) was obtained to identify the interproton connectivities in the drug molecule. A molecular modeling program involving Monte Carlo simulation and energy minimization was employed to arrive at the structure of the drug. The program was run with and without the input of the interproton distances derived from the NOESY cross peaks. Both the protocols led to a structure of the drug which was generally similar to that reported from X-ray diffraction data on crystalline diltiazem hydrochloride (Kojic-Prodic, et al. Helv. Chim. Acta 1984, 67, 916-926). However, significant differences between the two structures were seen in the orientations of the substituent groups attached to the benzothiazepine ring. Substantial changes in the circular dichroic (CD) and 1H-NMR spectra of diltiazem were observed on addition of Ca2+ up to a mole ratio of 0.5 Ca2+ per drug. Relatively large changes were seen in 1H resonances of the N-methyl protons and the methylene protons attached to the heterocyclic nitrogen. Analysis of the binding isotherms from CD data at 22 +/- 1 degrees C indicated a 2:1 drug:Ca2+ "sandwich" complex with an estimated dissociation constant of 140 microM. One-dimensional difference NOE and two-dimensional NOESY spectra revealed interproton connectivities between two drug molecules that were compatible with the sandwich complex formation. The interproton distances derived from the volume integrals of the NOESY cross peaks were used as geometrical constraints in modeling the Ca(2+)-bound conformation of diltiazem. The minimum-energy conformation corresponded to the sandwich complex where Ca2+ was coordinated to three oxygens in each of the two drug molecules. Combined with our earlier data on the ability of diltiazem to translocate Ca2+ across the lipid bilayer in synthetic liposomes (Ananthanarayanan, V.S.; Taylor, L.; Pirritano, S.Biochem. Cell Biol. 1992, 70, 608-612), the structural data presented here point to a role for Ca2+ in the interaction of diltiazem with its membrane-bound receptor.     

Decisions of the Party and the tasks of the All-Union Society of Pathologicoanatomists

The ways and forms of work of the All-Union and regional scientific societies of pathology in realization of the CPSU CC Degree "On Further Improvement of Ideological and Political Education Work" are discussed. It is suggested that the entire activity of the pathology societies be directed at the solution of the two main objectives extensive development and perfection of methodology of research work and direct participation of the pathology societies in the educational work among their members.