Cycloidal-spiral sampling for three-modal x-ray CT flyscans with two-dimensional phase sensitivity.

We present a flyscan compatible acquisition scheme for three-modal X-Ray Computed Tomography (CT) with two-dimensional phase sensitivity. Our approach is demonstrated using a "beam tracking" setup, through which a sample's attenuation, phase (refraction) and scattering properties can be measured from a single frame, providing three complementary contrast channels. Up to now, such setups required the sample to be stepped at each rotation angle to sample signals at an adequate rate, to prevent resolution losses, anisotropic resolution, and under-sampling artefacts. However, the need for stepping necessitated a step-and-shoot implementation, which is affected by motors' overheads and increases the total scan time. By contrast, our proposed scheme, by which continuous horizontal and vertical translations of the sample are integrated with its rotation (leading to a "cycloidal-spiral" trajectory), is fully compatible with continuous scanning (flyscans). This leads to greatly reduced scan times while largely preserving image quality and isotropic resolution.

Coronavirus Disease 2019 (COVID-19) Vaccination for Children: Position Statement of Indian Academy of Pediatrics Advisory Committee on Vaccination and Immunization Practices.

JUSTIFICATION: Data generated after the first wave has revealed that some children with coronavirus 19 (COVID-19) can become seriously ill. Multi-inflammatory syndrome in children (MIS-C) and long COVID cause significant morbidity in children. Prolonged school closures and quarantine have played havoc with the psychosocial health of children. Many countries in the world have issued emergency use authorisation (EUA) of selected Covid-19 vaccines for use in children. In India, a Subject Expert Committee (SEC) has recommended the use of Covaxin (Bharat Biotech) for children from the ages of 2-18 years. The recommendation has been given to the Drugs Controller General of India (DCGI) for final approval. OBJECTIVE: To provide an evidence-based document to guide the pediatricians on the recommendation to administer COVID vaccines to children, as and when they are available for use. PROCESS: Formulation of key questions was done by the committee, followed by review of literature on epidemiology and burden of Covid-19 in children, review of the studies on COVID vaccines in children, and the IAP stand on Covid-19 vaccination in children. The available data was discussed in the ACVIP focused WhatsApp group followed by an online meeting on 24 October, 2021, wherein the document was discussed in detail and finalized. RECOMMENDATIONS: The IAP supports the Government of India's decision to extend the COVID-19 vaccination program to children between 2-18 years of age. Children with high-risk conditions may be immunized on a priority basis. The IAP and its members should be a partner with the Government of India, in the implementation of this program and the surveillance that is necessary following the roll-out.

Revealing NOTCH-dependencies in synaptic targets associated with Alzheimer's disease.

Recent studies have identified NOTCH signaling as a contributor of neurodegeneration including Alzheimer's disease' (AD) pathophysiology. As part of the efforts to understand molecular mechanisms and players involved in neurodegenerative dementia, we employed transgenic mouse models with Notch1 and Rbpjk loss of function (LOF) mutation in pyramidal neurons of the CA fields. Using RNA-seq, we have investigated the differential expression of NOTCH-dependent genes either upon environmental enrichment (EE) or upon kainic acid (KA) injury. We found a substantial genetic diversity in absence of both NOTCH1 receptor or RBPJK transcriptional activator. Among differentially expressed genes, we observed a significant upregulation of Gabra2a in both knockout models, suggesting a role for NOTCH signaling in the modulation of E/I balance. Upon excitotoxic stimulation, loss of RBPJK results in decreased expression of synaptic proteins with neuroprotective effects. We confirmed Nptx2, Npy, Pdch8, TncC as direct NOTCH1/RBPJK targets and Bdnf and Scg2 as indirect targets. Finally, we translate these findings into human entorhinal cortex containing the hippocampal region from AD patients performing targeted transcripts analysis. We observe an increased trend for RBPJK and the ligand DNER starting in the mild-moderate stage of the disease with no change of NOTCH1 expression. Alongside, expression of the Notch targets Hes5 and Hey1 tend to rise in the intermediate stage of the disease and drop in severe AD. Similarly the newly discovered NOTCH targets, NPTX2, NPY, BDNF show an up-warding tendency during the mild-moderate stage, and decline in the severe phase of the disease. This study identifies NOTCH as a central signaling cascade capable of modulating synaptic transmission in response to excitatory insult through the activation of neuroprotective genes that have been associated to AD.

Notch signaling in response to excitotoxicity induces neurodegeneration via erroneous cell cycle reentry.

Neurological disorders such as Alzheimer's disease, stroke and epilepsy are currently marred by the lack of effective treatments to prevent neuronal death. Erroneous cell cycle reentry (CCR) is hypothesized to have a causative role in neurodegeneration. We show that forcing S-phase reentry in cultured hippocampal neurons is sufficient to induce neurodegeneration. We found that kainic-acid treatment in vivo induces erroneous CCR and neuronal death through a Notch-dependent mechanism. Ablating Notch signaling in neurons provides neuroprotection against kainic acid-induced neuronal death. We further show that kainic-acid treatment activates Notch signaling, which increases the bioavailability of CyclinD1 through Akt/GSK3ß pathway, leading to aberrant CCR via activation of CyclinD1-Rb-E2F1 axis. In addition, pharmacological blockade of this pathway at critical steps is sufficient to confer resistance to kainic acid-induced neurotoxicity in mice. Taken together, our results demonstrate that excitotoxicity leads to neuronal death in a Notch-dependent manner through erroneous CCR.

Breast gangrene in an HIV-positive patient.

INTRODUCTION: Breast gangrene has been reported as a complication following puerperal sepsis, breast surgery, nipple piercings, warfarin toxicity, etc. We report a case of primary breast gangrene in an HIV-positive individual which, to the best of our knowledge, is the first of its kind. CASE REPORT: A 40-year-old previously healthy woman presented with fulminating left breast gangrene. She was detected to be HIV positive. Mastectomy was performed. The detailed management of the condition is discussed. CONCLUSION: Severe necrotising infections may be initial manifestations of HIV infection and patients with such infections should be screened for HIV.

Thermo-expandable intra-prostatic stent in the treatment of acute urinary retention in elderly patients with significant co-morbidities.

We assess the use of thermo-expandable intra-prostatic stent (Memokath, Engineers and Doctors A/S, Denmark) for the treatment of acute urinary retention (AUR) in men with significant co-morbidities for transurethral resection of prostate (TURP). We evaluate the pre- and post-operative complications, duration of stents in-situ and patients quality of life after the stent insertion. Patients with significant co-morbidities presenting with AUR were selected, who were unfit for TURP. The co-morbidities included ischaemic heart disease, congestive heart failure, and chronic obstructive pulmonary disease. The exclusion criteria were bladder tumour and atonic bladder. The Memokath stents were inserted using a flexible cystoscope under local anaesthesia. The patients were followed up at 3 and 6 months after the procedure and the ones who remained alive were asked to complete self-administered questionnaires and IPSS scores. Fifteen men with acute urinary retention were recruited for stent insertion with the mean age of 87 years. No peri-operative complications were recorded. Three patients died after the insertion with functional Memokath in-situ. Nine patients had good functioning stents post-operatively, and remain catheter free up to 30 months after the procedure. The mean duration of stent life was 18 months. Three long-term complications were detected, including stent migration and prostate overgrowth. The Memokath is a good option for frail elderly patients presenting with AUR. The procedure is safe and has minimal long term complications. The stent also provides a sustained good quality of life for patients and avoids the necessity of long term catheterisation.

Non seminomatous germ cell tumour of a solitary testis in a 70-year-old man: a rare case.

We report a rare case of a 70-year-old patient who presented with undifferentiated malignant teratoma arising from a solitary testis. The literature review highlights the rarity of such tumour in this age group, and this may represent the oldest reported patient with non seminomatous germ cell tumour of testicle.

Therapeutic potential of yoga practices in modifying cardiovascular risk profile in middle aged men and women.

AIMS OF STUDY: To study effect of yoga on the physiological, psychological well being, psychomotor parameter and modifying cardiovascular risk factors in mild to moderate hypertensive patients. METHODS: Twenty patients (16 males, 4 females) in the age group of 35 to 55 years with mild to moderate essential hypertension underwent yogic practices daily for one hour for three months. Biochemical, physiological and psychological parameters were studied prior and following period of three months of yoga practices, biochemical parameters included, blood glucose, lipid profile, catecholmines, MDA, Vit. C cholinesterase and urinary VMA. Psychological evaluation was done by using personal orientation inventory and subjective well being. RESULTS: Results showed decrease in blood pressure and drug score modifying risk factors, i.e. blood glucose, cholesterol and triglycerides decreased overall improvement in subjective well being and quality of life. There was decrease in VMA catecholamine, and decrease MDA level suggestive decrease sympathetic activity and oxidant stress. CONCLUSION: Yoga can play an important role in risk modification for cardiovascular diseases in mild to moderate hypertension.

Sphingomyelinase converts lipoproteins from apolipoprotein E knockout mice into potent inducers of macrophage foam cell formation.

The apoE knockout (E0) mouse is one of the most widely used animal models of atherosclerosis, and there may be similarities to chylomicron remnant-induced atherosclerosis in humans. Although the lesions of these mice contain large numbers of cholesteryl ester (CE)-laden macrophages (foam cells), E0 plasma lipoproteins are relatively weak inducers of cholesterol esterification in macrophages. Previous in vivo work has suggested that arterial wall sphingomyelinase (SMase) may promote atherogenesis in the E0 mouse, perhaps by inducing subendothelial lipoprotein aggregation and subsequent foam cell formation. The goal of the present study was to test the hypothesis that the modification of E0 lipoproteins by SMase converts these lipoproteins into potent inducers of macrophage foam cell formation. When d<1.063 E0 lipoproteins were pretreated with SMase and then incubated with E0 macrophages, cellular CE mass and stimulation of the cholesterol esterification pathway were increased approximately 5-fold compared with untreated lipoproteins. SMase-treated E0 lipoproteins were more potent stimulators of cholesterol esterification than either E0 lipoproteins in the presence of lipoprotein lipases or oxidized E0 lipoproteins. The uptake and degradation of SMase-treated E0 lipoproteins by macrophages were saturable and specific and substantially inhibited by partial proteolysis of cell-surface proteins. Uptake and degradation were diminished by an anti-apoB antibody and by competition with human S(f) 100-400 hypertriglyceridemic VLDL, raising the possibility that a receptor that recognizes apoB-48 might be involved. In conclusion, SMase-modification of E0 lipoproteins, a process previously shown to occur in lesions, may be an important mechanism for foam cell formation in this widely studied model of atherosclerosis. Moreover, the findings in this report may provide important clues regarding the atherogenicity of chylomicron remnants in humans.

A randomized, double-blind, parallel-group, comparative safety, and efficacy trial of oral co-artemether versus oral chloroquine in the treatment of acute uncomplicated Plasmodium falciparum malaria in adults in India.

In India, treatment of acute, uncomplicated Plasmodium falciparum malaria is becoming increasingly difficult due to resistance to chloroquine, thus there is a need for new antimalarial drugs. CGP 56697 (co-artemether), a new drug, is a combination of artemether and lumefantrine in a single oral formulation (one tablet = 20 mg of artemether plus 120 mg of lumefantrine). In a double-blind study, 179 patients with acute uncomplicated P. falciparum malaria were randomly assigned to receive either CGP (n = 89) given as a short course of 4 x 4 tablets over a 48-hr period or chloroquine (n = 90) given as four tablets (one tablet = 150 mg of chloroquine base) initially, followed by two tablets each at 6-8, 24, and 48 hr. Due to a death in the chloroquine group and a decrease in the chloroquine cure rate to < 50% (based on the blinded overall cure rate at that time), recruitment was terminated prematurely. CGP 56697 showed a superior 28-day cure rate (95.4% versus 19.7%; P < 0.001), time to parasite clearance (median = 36 versus 60 hr; P < 0.001), and resolution of fever (median = 18 versus 27 hr; P = 0.0456). This drug provides a safe, effective, and rapid therapy for the treatment of acute uncomplicated P. falciparum malaria.

Creation of a mouse model for non-neurological (type B) Niemann-Pick disease by stable, low level expression of lysosomal sphingomyelinase in the absence of secretory sphingomyelinase: relationship between brain intra-lysosomal enzyme activity and central nervous system function.

Most lysosomal storage diseases result in neurodegeneration, but deficiencies in the same enzymes can also lead to syndromes without neurologic manifestations. The hypothesis that low levels of residual, intra-lysosomal enzymatic activities in the central nervous system (CNS) are protective has been difficult to prove because of inconsistencies in assays of tissue samples. Experimental correction of lysosomal enzyme deficiencies in animal models suggests that low-level enzymatic activity may reduce CNS pathology, but these results are difficult to interpret owing to the partial and transient nature of the improvements, the presence of secretory hydrolases, and other confounding factors. Using a novel transgenic/knockout strategy to manipulate the intracellular targeting of a hydrolase, we created a mouse that stably expresses low levels of lysosomal sphingomyelinase (L-SMase) in the complete absence of secretory sphingomyelinase (S-SMase). The brains of these mice exhibited 11.5-18.2% of wild-type L-SMase activity, but the cerebellar Purkinje cell layer, which is lost by 4 months of age in mice completely lacking L- and S-SMase, was preserved for at least 8 months. The L-SMase activities in other organs were 1-14% of wild-type levels, and by 8 months of age all peripheral organs had accumulated sphingomyelin and demonstrated pathological intracellular inclusions. Most importantly, L-SMase-expressing mice showed no signs of the severe neurologic disease observed in completely deficient mice, and their life span and general health were essentially normal. These findings show that stable, continuous, low-level expression of intra-lysosomal enzyme activity in the brain can preserve CNS function in the absence of secretory enzyme or other confounding factors.

Acute systemic inflammation up-regulates secretory sphingomyelinase in vivo: a possible link between inflammatory cytokines and atherogenesis.

Inflammation plays a critical role in atherogenesis, yet the mediators linking inflammation to specific atherogenic processes remain to be elucidated. One such mediator may be secretory sphingomyelinase (S-SMase), a product of the acid sphingomyelinase gene. The secretion of S-SMase by cultured endothelial cells is induced by inflammatory cytokines, and in vivo data have implicated S-SMase in subendothelial lipoprotein aggregation, macrophage foam cell formation, and possibly other atherogenic processes. Thus, the goal of this study was to seek evidence for S-SMase regulation in vivo during a physiologically relevant inflammatory response. First, wild-type mice were injected with saline or lipopolysaccharide (LPS) as a model of acute systemic inflammation. Serum S-SMase activity 3 h postinjection was increased 2- to 2.5-fold by LPS (P < 0.01). To determine the role of IL-1 in the LPS response, we used IL-1 converting enzyme knockout mice, which exhibit deficient IL-1 bioactivity. The level of serum S-SMase activity in LPS-injected IL-1 converting enzyme knockout mice was approximately 35% less than that in identically treated wild-type mice (P < 0.01). In LPS-injected IL-1-receptor antagonist knockout mice, which have an enhanced response to IL-1, serum S-SMase activity was increased 1. 8-fold compared with LPS-injected wild-type mice (P < 0.01). Finally, when wild-type mice were injected directly with IL-1beta, tumor necrosis factor alpha, or both, serum S-SMase activity increased 1. 6-, 2.3-, and 2.9-fold, respectively (P < 0.01). These data show regulation of S-SMase activity in vivo and they raise the possibility that local stimulation of S-SMase may contribute to the effects of inflammatory cytokines in atherosclerosis.

Sphingomyelinase, an enzyme implicated in atherogenesis, is present in atherosclerotic lesions and binds to specific components of the subendothelial extracellular matrix.

Atherosclerotic lesions contain an extracellular sphingomyelinase (SMase) activity that hydrolyzes the sphingomyelin of subendothelial low density lipoprotein (LDL). This SMase activity may promote atherosclerosis by enhancing subendothelial LDL retention and aggregation, foam cell formation, and possibly other atherogenic processes. The results of recent cell-culture studies have led to the hypothesis that a specific molecule called secretory SMase (S-SMase) is responsible for the SMase activity known to be in lesions, although its presence in atheromata had not been examined directly. Herein we provide immunohistochemical and biochemical support for this hypothesis. First, 2 different antibodies against S-SMase detected extracellular immunoreactive protein in the intima of mouse, rabbit, and human atherosclerotic lesions. Much of this material in lesions appeared in association with the subendothelial matrix. Second, binding studies in vitro demonstrated that (125)I-S-SMase adheres to the extracellular matrix of cultured aortic smooth muscle and endothelial cells, specifically to the laminin and collagen components. Third, in its bound state, S-SMase retains substantial enzymatic activity against lipoprotein substrates. Overall, these data support the hypothesis that S-SMase is an extracellular arterial wall SMase that contributes to the hydrolysis of the sphingomyelin of subendothelial LDL. S-SMase may therefore be an important participant in atherogenesis through local enzymatic effects that stimulate subendothelial retention and aggregation of atherogenic lipoproteins.

Expression of the divergent transcription unit containing the yeast PET122 and OXA1 genes.

The nuclear PET122 gene of S. cerevisiae encodes a mitochondrial-localized protein that activates initiation of translation of the mitochondrial mRNA from the COX3 gene, which encodes subunit III of cytochrome c oxidase. The PET122 locus contains two divergent transcription units: one is involved in expression of PET122 mRNA and the mRNA for an adjacent gene OXA1, which is also required for cytochrome c oxidase biogenesis, and the other is involved in expression of an antisense RNA that is complementary to about two thirds of the PET122 mRNA and an adjacent gene YER152C of unknown function. Steady state levels of OXA1, PET122 sense and PET122 antisense RNAs were measured after growth of yeast cells under catabolite repressing or derepressing conditions, or after deletion of portions of the 5' flanking DNA of the genes. The results reported here indicate that the PET122 and OXA1 genes are unconventional in terms of the control of their transcription. Neither possesses a canonical TATA element and they exhibit no apparent need for native upstream DNA. These results raise the interesting possibility that PET122 and OXA1 transcription is controlled by downstream DNA, perhaps located within the coding regions of the respective genes.

Poor gametocytocidal activity of 45 mg primaquine in chloroquine-treated patients with acute, uncomplicated, Plasmodium falciparum malaria in Mumbai (Bombay): an issue of public-health importance.

In the city of Mumbai (formerly Bombay), chloroquine (CQ) continues to be recommended as the drug of first choice for the treatment of Plasmodium vivax and P. falciparum infections, even though > 50% of local isolates of P. falciparum are resistant to it. Primaquine, an 8-aminoquinoline is also given to patients with falciparum malaria, in a single, 45-mg dose, to kill the gametocytes and so reduce transmission. The gametocytocidal activity of supervised primaquine (45 mg given on day 8) was investigated in 90 patients who had been treated with CQ. Of these, 15 were found to be CQ-sensitive patients, 61 were resistant (49, eight and four considered RI, RII and RIII, respectively) and 14 were lost before completion of the follow-up. The mean (S.D.) baseline gametocytaemias in the CQ-sensitive and RI-resistant cases were 665.1 (411.3) and 1537.4 (1045.5)/microliter, respectively. Despite supervised primaquine treatment, four of the 15 CQ-sensitive patients and 32 of the 49 patients found to be RI-resistant had gametocytes on day 29. There therefore appears to be a need to review the current, gametocytocidal, primaquine-dosage schedule and to re-treat patients who remain gametocytaemic with higher doses of primaquine, as an important, transmission-blocking strategy.

Multiple forms of arginase are differentially expressed from a single locus in Neurospora crassa.

The Neurospora crassa catabolic enzyme, arginase (L-arginine amidinohydrolase, EC 3.5.3.1), exists in multiple forms. Multiple forms of arginase are found in many vertebrates, but this is the only reported example in a microbial organism. The two major forms are structurally similar with subunit sizes of 36 and 41 kDa, respectively. The larger form is produced by mycelia growing in arginine-supplemented medium. Both forms are localized in the cytosol. The structural gene for arginase, aga, has been cloned and sequenced; it contains a 358-codon open reading frame with three in-frame ATGs at the amino terminus. Mutagenesis of these ATGs revealed that the first ATG initiates the 41-kDa protein and the third ATG initiates the 36-kDa protein. Mutation of the second ATG has no effect on translation. Northern analysis demonstrated that a 1.4-kilobase (kb) transcript is synthesized in minimal medium and both a 1.4- and 1.7-kb transcript are produced in arginine-supplemented medium. Primer extension identified the 5' ends of each transcript and demonstrated that the first and third ATG of the open reading frame are the initial AUGs of the 1.7- and 1. 4-kb mRNA, respectively. The results suggest that a basal promoter produces the 1.4-kb transcript and an arginine "activated" promoter is responsible for the 1.7-kb transcript. Tandem promoters are rare in eukaryotic organisms, and they often regulate developmental or tissue-specific gene expression. The possibility that arginase has a role in differentiation in N. crassa is being investigated.

Human vascular endothelial cells are a rich and regulatable source of secretory sphingomyelinase. Implications for early atherogenesis and ceramide-mediated cell signaling.

We recently reported that macrophages and fibroblasts secrete a Zn2+-dependent sphingomyelinase (S-SMase), which, like lysosomal SMase, is a product of the acid SMase gene. S-SMase may cause subendothelial retention and aggregation of lipoproteins during atherogenesis, and the acid SMase gene has been implicated in ceramide-mediated cell signaling, especially involving apoptosis of endothelial cells. Because of the central importance of the endothelium in each of these processes, we now sought to examine the secretion and regulation of S-SMase by vascular endothelial cells. Herein we show that cultured human coronary artery and umbilical vein endothelial cells secrete massive amounts of S-SMase (up to 20-fold more than macrophages). Moreover, whereas S-SMase secreted by macrophages and fibroblasts is almost totally dependent on the addition of exogenous Zn2+, endothelium-derived S-SMase was partially active even in the absence of added Zn2+. Secretion of S-SMase by endothelial cells occurred both apically and basolaterally, suggesting an endothelial contribution to both serum and arterial wall SMase. When endothelial cells were incubated with inflammatory cytokines, such as interleukin-1beta and interferon-gamma, S-SMase secretion by endothelial cells was increased 2-3-fold above the already high level of basal secretion, whereas lysosomal SMase activity was decreased. The mechanism of interleukin-1beta-stimulated secretion appears to be through increased routing of a SMase precursor protein through the secretory pathway. In summary, endothelial cells are a rich and regulatable source of enzymatically active S-SMase, suggesting physiologic and pathophysiologic roles for this enzyme.