Cognitive impairment in asymptomatic carotid artery stenosis is associated with abnormal segments in the Circle of Willis.

OBJECTIVE: Our group has previously demonstrated that patients with asymptomatic carotid artery stenosis (ACAS) demonstrate cognitive impairment. One proposed mechanism for cognitive impairment in patients with ACAS is cerebral hypoperfusion due to flow-restriction. We tested whether the combination of a high-grade carotid stenosis and inadequate cross-collateralization in the Circle of Willis (CoW) resulted in worsened cognitive impairment. METHODS: Twenty-four patients with high-grade (≥70% diameter-reducing) ACAS underwent carotid duplex ultrasound, cognitive assessment, and 3D time-of-flight magnetic resonance angiography (MRA). The cognitive battery consisted of nine neuropsychological tests assessing four cognitive domains: learning and recall, attention and working memory, motor and processing speed, and executive function. Raw cognitive scores were converted into standardized T-scores. A structured interpretation of the MRA images was performed with each segment of the CoW categorized as being either normal or abnormal. Abnormal segments of the CoW were defined as segments characterized as narrowed or occluded due to congenital aplasia or hypoplasia, or acquired atherosclerotic stenosis or occlusion. Linear regression was used to estimate the association between the number of abnormal segments in the CoW, and individual cognitive domain scores. Significance was set to p<0.05. RESULTS: The mean age of the patients was 66.1 + 9.6 (mean + SD) years and 79.2% (n=19) were male. A significant negative association was found between the number of abnormal segments in the CoW and cognitive scores in the learning and recall (ß = -6.5, p = 0.01), and attention and working memory (ß = -7.0, p = 0.02) domains. There was a trend suggesting a negative association in the motor and processing speed (ß = -2.4, p = 0.35) and executive function (ß = -4.5, p = 0.06) domains that did not reach significance. CONCLUSION: In patients with high-grade ACAS, the concomitant presence of increasing occlusive disease in the CoW correlates with worse cognitive function. This association was significant in the learning and recall and attention and working memory domains. While motor and processing speed and executive function also declined numerically with increasing abnormal segments in the CoW, the relationship was not significant. Since flow restriction at a carotid stenosis compounded by inadequate collateral compensation across a diseased CoW worsens cerebral perfusion, our findings support the hypothesis that cerebral hypoperfusion underlies the observed cognitive impairment in patients with ACAS.

Understanding factors associated with continuation of intrauterine device use in Gujarat and Rajasthan, India: a cross-sectional household study.

The Government of India has promoted the expansion of access to and uptake of intrauterine devices (IUDs), during both the interval (IIUD) and postpartum (PPIUD) periods, as part of its Family Planning 2020 initiative. This study, conducted by EngenderHealth as part of the Expanding Access to IUD Services in India project, examines IIUD and PPIUD continuation rates over time and investigates factors associated with IUD continuation. We recruited respondents (N = 5024) through a repeated cross-sectional household study between February and December 2019. We identified respondents using IUD client data from public health facility registers in 20 districts of Gujarat and Rajasthan. We compared continuation rates for IIUD and PPIUD adopters and used regression analyses to measure the association between continuation and demographic, quality of care, and counselling variables. IIUD continuation rates decreased from 85.6% to 78.3% and PPIUD rates decreased from 78.5% to 70.7% between month 3 and month 12. Clients experiencing side effects or other problems were 15 times more likely to discontinue IUD use than clients who did not. Clients who received IUD counselling prior to insertion were more likely to continue than those who did not. IUD continuation increased significantly in cases where both partners jointly selected the method compared to situations where women decided alone. Several sociodemographic factors were associated with continuation. Our study demonstrates the value and benefits of programmes offering IUD services emphasising quality counselling and client-centred care to increase access, uptake, and continuation.

A qualitative study of the processes by which carers of people with dementia derive meaning from caring.

BACKGROUND: Most individuals with dementia live in the community, receiving care from family or lay carers. Carers' wellbeing, and the quality of the care they provide, partly depends on their ability to derive meaning from caring for someone with dementia. Both carers' previous relationship with their relative and the caregiving process itself contribute to this sense of meaning. However, it remains unclear why some carers derive meaning from these sources, whereas others do not. OBJECTIVE: To further explore the processes by which carers derive a sense of meaning from caring. METHODS: Representative case sampling was used to recruit a purposive sample of 20 carers for individuals living with dementia. In-depth semi-structured interviews were audio-recorded and transcribed, and analysed using pluralist qualitative methodology. RESULTS: A framework of three sources from which carers derived meaning from caring was identified, encompassing: carers' perceptions of how 'right' or 'symmetrical' caring felt in light of their current and previous relationship with the person with dementia; maintenance of a 'protected' sense of self within the care relationship; and carers' perceptions of their 'social connectedness' outside the relationships. CONCLUSION: Holistic assessment based on this framework could help to tailor individualised provision of support, foster resilience and safeguard carers' well-being.

An efficient protocol for in vitro direct shoot organogenesis of Sesamum indicum L. using cotyledon as explant.

Establishment of a suitable regeneration protocol is a pre-requisite to carry out transformation study in Sesamum indicum L. (sesame). In this paper, different parameters of regeneration were standardised to develop an efficient protocol for in vitro plant regeneration via direct adventitious shoot organogenesis using de-embryonated cotyledons of sesame as explants. Among the various treatments of MS medium supplemented with 6-benzylaminopurine, thidiazuron and indole-3-acetic acid, maximum regeneration frequency (25.93  ±  2.21%) was obtained in BTI 4 medium (MS supplemented with 33.33 µM BAP with 2.85 µM IAA) within 6 weeks of culture. Regeneration frequency increased further (50.37 ± 2.49%) by fortifying BTI 4 with 29.43 µM silver nitrate (AG 3 medium). Pre-culture of cotyledon explants in AB 3 medium (AG 3 supplemented with 3.78 µM abscisic acid) for 14 days followed by sub-culture in AG 3 medium further improved the regeneration frequency (68.15 ± 2.68%). The highest rate of shoot regeneration (94.82 ± 1.34%) was obtained by pre-culturing 4-day-old cotyledon in a vertical position in AB 3 medium for 14 days and sub-culturing in AG 3 medium for 4 weeks. Regenerated shoots proliferated in MS medium supplemented with 4.44 µM BAP and 1.44 µM gibberelic acid (GA3). The highest frequency (65.33 ± 3.78%) of root induction was achieved by culturing the elongated shoots in MS medium supplemented with 2.69 µM α-naphthalene acetic acid (NAA) for 6 weeks. Rooted plants were acclimatised in soilrite and transferred to soil after 6-8 weeks. The rate of acclimatisation of plants was 76%.

Flavonol isolated from ethanolic leaf extract of Thuja occidentalis arrests the cell cycle at G2-M and induces ROS-independent apoptosis in A549 cells, targeting nuclear DNA.

OBJECTIVES: The K-ras gene mutation commonly found in lung adenocarcinomas contributes to their non-invasive expansion. Our main objective here was to develop a chemopreventive agent against K-ras-mutated lung adenocarcinoma cell line like-A549. MATERIALS AND METHODS: We isolated flavonol from ethanolic leaf extract of Thuja occidentalis, and evaluated its apoptotic potentials on A549 cells. They were treated with 1-10 µg/ml of flavonol and viability was tested retaining normal lung cells L-132 as control. We performed assays such as TUNEL, annexin V, cell-cycle and mitochondrial membrane potentials, by FACS analysis. ROS-mediated oxidative stress and drug-DNA interactions were analysed along with gene expression studies for p53, Bax-Bcl2, cytochrome c, the caspase cascade genes and PARP. RESULTS: Flavonol reduced A549 cell viability in a dose- and time-dependent manner (IC50 value = 7.6 ± 0.05 µg/ml following 48 h incubation) sparing normal L-132 cells. It effected G2-M phase cell cycle arrest and apoptosis, as indicated by progressive increase in the sub-G1, annexin V and TUNEL-positive cell populations. Apoptotic effects appeared to be mitochondria-dependent, caspase-3-mediated, but ROS-independent. Analysis of circular dichroism data revealed that flavonol intercalated with nuclear DNA. In vivo studies on non small cell lung carcinoma (NSCLC)-induced mice confirmed anti-cancer potential of flavonol. CONCLUSION: Flavonol-induced apoptosis apparently resulted from intercalation of cells' nuclear DNA. Flavonol inhibited growth of induced lung tumours in the mice, indicating its potential as an effective agent against NSCLC.

L-pGlu-(2-propyl)-L-His-L-ProNH2 attenuates 4-aminopyridine-induced epileptiform activity and sodium current: a possible action of new thyrotropin-releasing hormone analog for its anticonvulsant potential.

L-PGlu-(2-propyl)-L-His-L-ProNH2 (NP-647) is a CNS active thyrotropin-releasing hormone (TRH) analog with potential application in various CNS disorders including seizures. In the present study, mechanism of action for protective effect of NP-647 was explored by studying role of NP-647 on epileptiform activity and sodium channels by using patch-clamp methods. Epileptiform activity was induced in subicular pyramidal neurons of hippocampal slice of rat by perfusing 4-aminopyridine (4-AP) containing Mg⁺²-free normal artificial cerebrospinal fluid (nACSF). Increase in mean firing frequency was observed after perfusion of 4-AP and zero Mg⁺² (2.10±0.47 Hz) as compared with nACSF (0.12±0.08 Hz). A significant decrease in mean firing frequency (0.61±0.22 Hz), mean frequency of epileptiform events (0.03±0.02 Hz vs. 0.22±0.05 Hz of 4-AP+0 Mg), and average number of action potentials in paroxysmal depolarization shift-burst (2.54±1.21 Hz vs. 8.16±0.88 Hz of 4-AP+0 Mg) was observed. A significant reduction in peak dV/dt (246±19 mV ms⁻¹ vs. 297±18 mV ms⁻¹ of 4-AP+0 Mg) and increase (1.332±0.018 ms vs. 1.292±0.019 ms of 4-AP+0 Mg) in time required to reach maximum depolarization were observed indicating role of sodium channels. Concentration-dependent depression of sodium current was observed after exposure to dorsal root ganglion neurons to NP-647. NP-647 at different concentrations (1, 3, and 10 µM) depressed sodium current (15±0.5%, 50±2.6%, and 75±0.7%, respectively). However, NP-647 did not show change in the peak sodium current in CNa18 cells. Results of present study demonstrated potential of NP-647 in the inhibition of epileptiform activity by inhibiting sodium channels indirectly.

Intra-species variability in ITS-1 sequences of Haemonchus contortus isolated from goats in West Bengal, India.

This study evaluated the existence of different genotypes of Haemonchus contortus prevailing among goats in West Bengal, India. These parasites were isolated from the abomasum of goat intestine and the molecular characterization was performed by comparing variation of nucleotide sequences of the internal transcribed spacer 1 (ITS-1) gene region. Single-strand conformation polymorphism (SSCP) analysis of ITS-1 amplified product showed the presence of three distinct conformations both in male and female parasites. The sequence analysis of conformations showed two single nucleotide polymorphisms (SNP) in male parasites at nucleotide positions 106 and 107 and one SNP was detected in female parasites at nucleotide position 157. These nucleotide variations in different isolates did not alter the interior loop structure of the predicted secondary RNA, therefore we believe these variations may not be responsible for any evolutionary changes among conformations.

Green Synthesis of Fe and Fe/Pd Bimetallic Nanoparticles in Membranes for Reductive Degradation of Chlorinated Organics.

Membranes containing reactive nanoparticles (Fe and Fe/Pd) immobilized in a polymer film (polyacrylic acid, PAA-coated polyvinylidene fluoride, PVDF membrane) are prepared by a new method. In the present work a biodegradable, non-toxic -"green" reducing agent, green tea extract was used for nanoparticle (NP) synthesis, instead of the well-known sodium borohydride. Green tea extract contains a number of polyphenols that can act as both chelating/reducing and capping agents for the nanoparticles. Therefore, the particles are protected from oxidation and aggregation, which increases their stability and longevity. The membrane supported NPs were successfully used for the degradation of a common and highly important pollutant, trichloroethylene (TCE). The rate of TCE degradation was found to increase linearly with the amount of Fe immobilized on the membrane, the surface normalized rate constant (k(SA)) being 0.005 L/m(2)h. The addition of a second catalytic metal, Pd, to form bimetallic Fe/Pd increased the k(SA) value to 0.008 L/m(2)h. For comparison purposes, Fe and Fe/Pd nanoparticles were synthesized in membranes using sodium borohydride as a reducing agent. Although the initial k(SA) values for this case (for Fe) are one order of magnitude higher than the tea extract synthesized NPs, the rapid oxidation reduced their reactivity to less than 20 % within 4 cycles. For the green tea extract NPs, the initial reactivity in the membrane domain was preserved even after 3 months of repeated use. The reactivity of TCE was verified with "real" water system.

Feasibility study of a smart pen for autonomous detection of concentration lapses during reading.

We implemented a portable smart pen system capable of detecting lapses in concentration during reading. An accelerometer and a microcontroller are embedded within a pen casing to record data as a user reads sections of text using the pen as a pointer. When a substantial pause in reading is detected, the system generates an appropriate warning or alarm. An accompanying software program can communicate with the pen through a USB interface to customize system parameters, record relevant data, and graph collected data over time. The overall effectiveness of a prototype system was tested on 11 normal volunteers and 3 persons with attention deficit disorder (ADD). The prototype system had probability of false alarm of 19%, and sensitivity of 82%. With further refinement, this system could enable patients with attention deficit/hyperactivity disorder maintain concentration during reading in a variety of environments.

Inhibition of human two-pore domain K+ channel TREK1 by local anesthetic lidocaine: negative cooperativity and half-of-sites saturation kinetics.

TWIK-related K+ channel TREK1, a background leak K+ channel, has been strongly implicated as the target of several general and local anesthetics. Here, using the whole-cell and single-channel patch-clamp technique, we investigated the effect of lidocaine, a local anesthetic, on the human (h)TREK1 channel heterologously expressed in human embryonic kidney 293 cells by an adenoviral-mediated expression system. Lidocaine, at clinical concentrations, produced reversible, concentration-dependent inhibition of hTREK1 current, with IC(50) value of 180 muM, by reducing the single-channel open probability and stabilizing the closed state. We have identified a strategically placed unique aromatic couplet (Tyr352 and Phe355) in the vicinity of the protein kinase A phosphorylation site, Ser348, in the C-terminal domain (CTD) of hTREK1, that is critical for the action of lidocaine. Furthermore, the phosphorylation state of Ser348 was found to have a regulatory role in lidocaine-mediated inhibition of hTREK1. It is interesting that we observed strong intersubunit negative cooperativity (Hill coefficient = 0.49) and half-of-sites saturation binding stoichiometry (half-reaction order) for the binding of lidocaine to hTREK1. Studies with the heterodimer of wild-type (wt)-hTREK1 and Delta119 C-terminal deletion mutant (hTREK1(wt)-Delta119) revealed that single CTD of hTREK1 was capable of mediating partial inhibition by lidocaine, but complete inhibition necessitates the cooperative interaction between both the CTDs upon binding of lidocaine. Based on our observations, we propose a model that explains the unique kinetics and provides a plausible paradigm for the inhibitory action of lidocaine on hTREK1.

Glutamate transporter blockade affects Ca(2+) responses in astrocytes.

Brief pretreatment of astrocytes in culture with glutamate (500 microM for 20 min), was earlier shown to significantly enhance the Ca(2+) responses to a depolarizing pulse. It is known that malfunction of glutamate transporters increases extracellular glutamate concentration. We hypothesized that pretreatment of astrocytes with glutamate in conditions where the glutamate transporter activity is blocked should cause further elevation of the Ca(2+) responses to a depolarizing pulse. To test the hypothesis we pretreated astrocytes in culture (primary rat astrocyte cultures) with glutamate (500 microM) and glutamate transport inhibitor, threo-beta-hydroxy-aspartate (200 microM, TBHA) or glutamate (500 microM) in Na(+) free extracellular solution for 20 min. The Ca(2+) responses were elicited by depolarization of the astrocyte to evoke voltage-gated Ca(2+) currents. Paradoxical attenuation of the Ca(2+) transients was observed when the glutamate pretreatment was done in conditions that blocked glutamate transport, accompanied by faster rise and decay times. When the experiments were done on astrocyte pairs that were pretreated with glutamate and TBHA, we observed attenuated Ca(2+) responses in the adjoining cell when compared with the depolarized cell. The results were contrary to our earlier observation of heightened responses in the adjoining cell of the astrocyte pair, in cells pretreated with glutamate alone. The attenuated Ca(2+) responses in astrocytes would imply decrease in the vesicular release of glutamate and ATP. Extracellular glutamate concentration dependent regulation of the Ca(2+) signaling mechanism thus seems to operate in astrocytes, which may be important in regulating the neurotoxic accumulation of glutamate in the extracellular space and the synapse.

Time-dependent molecular memory in single voltage-gated sodium channel.

Excitability in neurons is associated with firing of action potentials and requires the opening of voltage-gated sodium channels with membrane depolarization. Sustained membrane depolarization, as seen in pathophysiological conditions like epilepsy, can have profound implications on the biophysical properties of voltage-gated ion channels. Therefore, we sought to characterize the effect of sustained membrane depolarization on single voltage-gated Na+ channels. Single-channel activity was recorded in the cell-attached patch-clamp mode from the rNa(v)1.2 alpha channels expressed in CHO cells. Classical statistical analysis revealed complex nonlinear changes in channel dwell times and unitary conductance of single Na+ channels as a function of conditioning membrane depolarization. Signal processing tools like weighted wavelet Z (WWZ) and discrete Fourier transform analyses attributed a "pseudo-oscillatory" nature to the observed nonlinear variation in the kinetic parameters. Modeling studies using the hidden Markov model (HMM) illustrated significant changes in kinetic states and underlying state transition rate constants upon conditioning depolarization. Our results suggest that sustained membrane depolarization induces novel nonlinear properties in voltage-gated Na+ channels. Prolonged membrane depolarization also induced a "molecular memory" phenomenon, characterized by clusters of dwell time events and strong autocorrelation in the dwell time series similar to that reported recently for single enzyme molecules. The persistence of such molecular memory was found to be dependent on the duration of depolarization. Voltage-gated Na+ channel with the observed time-dependent nonlinear properties and the molecular memory phenomenon may determine the functional state of the channel and, in turn, the excitability of a neuron.

Ataxia and deafness in a young male: an unusual aetiology.

We report here a case of 18 year old male with tremors of hands, deafness, tendency to fall while walking, drowsiness and double vision of total duration 1(1/2) years. He had internuclear ophthalmoplegia, broken saccades, hypertonia and hyperreflexia of all four limbs, intention tremors, signs of gait and limb ataxia. Pupillary reactions and fundus examination were normal and signs of meningeal irritation or sensory neurological deficit were absent. MRI head and cervical spine with gadolinium enhancement revealed demyelination as evident from multiple oblong foci isointense on T1-weighted images and hyperintense on T2-weighted and fluid attenuated inversion recovery sequences in corpus callosum, sub-cortical white matter, right thalamus, pons and periaqueductal region of midbrain. Ill-defined linear hyperintense signals were observed in cervical spinal cord. No skeletal abnormality was noted in the skull or cervical spine. Oligoclonal bands were present in the cerebrospinal fluid. Brainstem auditory evoked potentials were abnormal, although visual evoked potentials were in normal range. A diagnosis of primary progressive multiple sclerosis (PPMS) was made fulfilling the revised criteria as laid down. In view of its presentation, it is a unique case of PPMS from India.

Characterization of contryphans from Conus loroisii and Conus amadis that target calcium channels.

Distinctly different effects of two closely related contryphans have been demonstrated on voltage-activated Ca(2+) channels. The peptides Lo959 and Am975 were isolated from Conus loroisii, a vermivorous marine snail and Conus amadis, a molluscivore, respectively. The sequences of Lo959 and Am975 were deduced by mass spectrometric sequencing (MALDI-MS/MS) and confirmed by chemical synthesis. The sequences of Lo959, GCP(D)WDPWC-NH(2) and Am975, GCO(D)WDPWC-NH(2) (O: 4-trans-hydroxyproline: Hyp), differ only at residue 3; Pro in Lo959, Hyp in Am975, which is identical to contryphan-P, previously isolated from Conus purpurascens, a piscivore; while Lo959 is a novel peptide. Both Lo959 and Am975 undergo slow conformational interconversion under reverse-phase chromatographic conditions, a characteristic feature of all contryphans reported thus far. Electrophysiological studies performed using dorsal root ganglion neurons reveal that both peptides target high voltage-activated Ca(2+) channels. While Lo959 increases the Ca(2+) current, Am975 causes inhibition. The results establish that subtle sequence effects, which accompany post-translational modifications in Conus peptides, can have dramatic effects on target ion channels.

Astrocytes in 17beta-estradiol treated mixed hippocampal cultures show attenuated calcium response to neuronal activity.

Glial cells in the brain are capable of responding to hormonal signals. The ovarian steroid hormone 17beta-estradiol, in addition to its actions on neurons, can directly affect glial cells. Estrogen receptors have been described on both neurons and astrocytes, suggesting a complex interplay between these two in mediating the effects of the hormone. Astrocytes sense and respond to neuronal activity with a rise in intracellular calcium concentration ([Ca(2+)](i)). Using simultaneous electrophysiology and calcium imaging techniques, we monitored neuronal activity evoked astrocyte ([Ca(2+)](i)) changes in mixed hippocampal cultures loaded with fluo-3 AM. Action potential firing in neurons, elicited by injecting depolarizing current pulses, was associated with ([Ca(2+)](i)) elevations in astrocytes, which could be blocked by 200 microM MCPG and also 1 microM TTX. We compared astrocytic ([Ca(2+)](i)) transients in control and 24-hour estradiol treated cultures. The amplitude of the ([Ca(2+)](i)) transient, the number of responsive astrocytes, and the ([Ca(2+)](i)) wave velocity were all significantly reduced in estradiol treated cultures. ([Ca(2+)](i)) rise in astrocytes in response to local application of the metabotropic glutamate receptor (mGluR) agonist t-ACPD was attenuated in estradiol treated cultures, suggesting functional changes in the astrocyte mGluR following 24-h treatment with estradiol. Since astrocytes can modulate synaptic transmission by release of glutamate, the attenuated ([Ca(2+)](i)) response seen following estradiol treatment could have functional consequences on astrocyte-neuron signaling.

FM1-43 measurements of local exocytotic events in rat melanotrophs.

We have explored the existence of fusion- and secretion-competent sites on the plasma membrane of peptide secreting rat pituitary melanotrophs at rest, and following stimulation with glutamate. We monitored changes in fluorescence of FM1-43, a styryl dye which labels plasma membrane. The results show spontaneous local increases in FM1-43 reporting changes in membrane surface area due to cumulative exocytosis. Addition of glutamate, further increased the occurrence of these events. Statistical analysis of local FM1-43 fluorescence changes suggests that this is due to the recruitment of inactive exocytotic domains and due to the stimulation of already active exocytotic domains.

An uncommon cause of scleroderma.

The human immunodeficiency virus (HIV) pandemic is nearly 20 years old. HIV infection is characterized by profound immunodeficiency resulting in an increased incidence of opportunistic infections and neoplasms. However, the greatest paradox is the occurrence of certain autoimmune disorders in the setting of HIV. These include diffuse interstitial lymphocytosis syndrome (DILS), reactive arthritis, systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA). It has also been seen that even in the absence of these well-defined diseases, various rheumatological manifestations such as arthralgias, arthritis, myopathy, vasculitis, and sicca syndrome are commonly associated with HIV. To the best of our knowledge, the association of HIV with scleroderma has not previously been reported.

Candidemia--an under-recognized nosocomial infection in Indian hospitals.

OBJECTIVE: To study the occurrence of candidemia as a nosocomial infection in a large Indian teaching hospital and to evaluate the predisposing factors for development of such infections. METHODS: One hundred and one hospitalized patients that developed signs and symptoms of nosocomial bloodstream infections were screened for candidemia and were analyzed for the various predisposing factors like the age of the patient, the duration of hospitalization before the development of fever, neutropenia, use of chemotherapeutic agents, central venous catheters, broad spectrum antibiotics, infection with HIV, diabetes mellitus, use of corticosteroids, administration of total parenteral nutrition, haemodialysis, use of mechanical ventilation, hematological or other malignancies, underlying disease, and any surgical procedure performed on the patient. Candidemic patients were followed up for outcome and the effect of nosocomial candidemia on mortality was assessed and analyzed statistically. RESULTS: Out of the 101 patients, seven patients had candidemia, an incidence in study population of 6.9%. Three (42.8%) were infected with albicans and the rest with non-albicans candidemia. All the patients with candidemia were admitted in the Intensive Care Units. Amongst the risk factors, the length of hospitalization (p = 0.018), broad-spectrum antibiotics (p = 0.045), central venous catheters (p = 0.005), mechanical ventilation (p = 0.0139) and total parenteral nutrition (p = 0.001) were found to be significantly related to acquisition of nosocomial candidemia. Mortality in the candidemic patients was influenced only by the age of the patients (p = 0.001). Although the mortality amongst the candidemic patients was twice as much as that of the patients not having this infection, still the difference did not reach significance (p = 0.117). CONCLUSION: Candidemia is an important problem in Indian hospitals. Diagnostic delays could be shortened by more active screening for candidemia especially in the intensive care settings. The rising incidence of non-albicans candidemia in the United States probably is true here as well. There should be a concerted effort to control known risk factors especially in intensive care units.

Inhibition of human TREK-1 channels by caffeine and theophylline.

Caffeine (1,3,7-trimethylxanthine) and theophylline (1,3-dimethylxanthine) are used for therapeutic purposes and can cause life-threatening convulsive seizures due to systemic toxicity. The mechanisms for the epileptogenicity of caffeine and theophylline are not clear. TWIK-related K(+) channels (TREK-1) are highly expressed in the human central nervous system and have a major role in the control of neuronal excitability by regulating the resting membrane potential. In view of their physiological significance, inhibition of TREK-1 channels may be implicated in caffeine- and theophylline-induced seizures. We thus investigated, using whole-cell patch-clamp technique, modulation of hTREK-1 channels expressed in Chinese hamster ovary (CHO) cells by caffeine and theophylline. Caffeine and theophylline produced reversible inhibition of TREK-1 channels in a concentration-dependent manner. The half-maximal inhibitory concentrations (IC(50)) for caffeine and theophylline were 377+/-54microM and 486+/-76microM, respectively. Caffeine and theophylline depolarized the membrane potential of CHO(TREK-1) cells in a reversible and concentration-dependent manner. Inhibition by caffeine (5mM) and theophylline (2mM) was attenuated in TREK-1 channels with mutation of the PKA consensus sequence at serine 348, suggesting the involvement of cAMP/PKA pathway in the inhibitory process. Inhibition of TREK-1 channels and consequent membrane depolarization may contribute to the convulsive seizures induced by toxic levels of caffeine and theophylline.